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Towards Cleaner TechnologiesA process story on biomass gasifiers for

heat applications in small and micro enterprises

TH E RMA L G A S I F I E R T E AM

Core TeamSunil DhingraSanjay Mande

P RamanS N Srinivas

Technical Support Team Field Implementation Team

Vinayak B Kulkarni E Joseph

Kusum Lata Raj Kumar

Gaurav Mishra M L Sharma

Yabbati Nagaraju (From 2002) Gurvinder Singh (till 1997)

N K Ram L B Thakur

H H Ninga Setty U Vellaikannu

Group LeaderV V N Kishore

Collaborating Manufacturers

List of firms who have been closely involved withmanufacture and installation of TERI gasifiers atdifferent stages of the process

2M Industries, MumbaiChanderpur Works, YamunanagarFigu Engineering Works, RanipoolParamount Enviroenergies, KottayamPunjab Engineering WorksRolltech Engineering Projects, New DelhiSilkTex Industries, KanakapuraUrjex Boilers, MeerutVijay Engineering Enterprises, BangaloreWestern India Carbonics Pvt Ltd, Junagarh

Facilitation/Management TeamSomnath Bhattacharjee, TERI (till 2003)H V Dayal, TERI (till 2002)H R Girija, SDC (till 2003)Pierre Jaboyedoff, Sorane SaP J Joseph (1996–1999)Veena Joshi, SDCM K Halpeth, TERI (from 2002)Urs Heierli, SDC (till 1999)Sameer Maithel, TERI (till 2006)Ajay Mathur, TERI (till 2000)C K Rao, ISPS (from 1999)Girish Sethi, TERI

Financial and Management Support

Swiss Agency for Development and Cooperation, IndiaIndo-Swiss Project Sikkim, GangtokSERI-2000, Bangalore

In addition, support has also been received from:Ministry of New and Renewable Energy (MNRE)Wuppertal Institute for Climate, Environment and

Energy, GermanyHimachal Pradesh Forest Sector Reform Project, Shimla

Collaborating Organizations

List of organizations who have been associated with theprocess in different capacities and at different stages

Bapuji Institute of Engineering and Technology,Davangere

BVB College of Engineering and Technology, HubliCentral Silk Technological Research Institute, BangaloreDepartment of Horticulture, SikkimDepartment of Sericulture – Andhra Pradesh,

Karnataka, Tamil NaduGram Vikas, MohudaI J Raju and Associates, New DelhiIndustrial Design Center, IIT, MumbaiNagarik Seva Mandal, AmbernathPioneer Magnesia Works, KharagodaRadha Soami Satsang, BeasRubber Board, KottayamSorane SA, SwitzerlandSymbiotec Research Associates, Bangalore

Towards Cleaner TechnologiesA process story on biomass gasifiers for

heat applications in small and micro enterprises

EditorsSanjay MandeV V N Kishore

NarratorR P Subramanian

Series EditorsGirish Sethi

Pierre JaboyedoffVeena Joshi

© The Energy and Resources Institute andSwiss Agency for Development and Cooperation, 2007

ISBN 81-7993-107-2

This document may be reproduced in whole or in part and in any form foreducational and non-profit purposes without special permission, providedacknowledgement of the source is made. SDC and TERI would appreciate receiving acopy of any publication that uses this document as a source.

Suggested format for citationMande S and Kishore V V N (eds). 2007Towards Cleaner Technologies: a process story on biomass gasifiers for heatapplications in small and micro enterprisesNew Delhi: The Energy and Resources Institute. 280 pp.

Published byT E R I PressThe Energy and Resources Institute Tel. 2468 2100 or 4150 4900Darbari Seth Block Fax 2468 2144 or 2468 2145IHC Complex, Lodhi Road India +91 • Delhi (0) 11New Delhi – 110 003 E-mail [email protected] Web www.teriin.org

Printed in India at I G Printers Pvt Ltd, New Delhi

CONTENTS

Foreword v

Preface vii

INTRODUCTION 1Small and micro enterprises in India 1The protected years 2Liberalization challenges 4

The environmental imperative 4A partnership is forged 5

SDC—human and institutional development 5TERI—global vision, local focus 6

The macro-level study 7The scope for intervention 8

Screening workshop, December 1994 9Getting started 10

Cluster-level intervention 10Finding the right technology 11Participatory technology 12Capacity building: key to sustainability 12

Structuring the interventions 13Action research 13

Competence pooling 15

vi Contents

CHARTING THE COURSE 17Energy from biomass 17Biomass-based enterprises 18Biomass gasification 20Exploring new avenues: TERI and gasifier technology 23The silk route 24

Overview 24Process—from silkworm egg to raw silk 26Silk reeling units: field realities 31SDC and TERI—early activities 32TERI’s field survey 34Exploring options 35

The spice route 36Overview 36Enter: SDC and TERI 43Exploring options 44

INTO THE FIELD 47Silk reeling 47

From lab to field: hindupur yarn 49Ramanagaram yarn: participatory approach 56Siddlaghatta yarn: low-cost approach 86Rewinding the reel—a barrier analysis 96

Silk dyeing 102Development of gasifier-based dyeing oven 102Manufacture and marketing 106

Large cardamom curing 109Developing the gasifier 114Test marketing of improved-quality cardamom 137Training and awareness generation 139Developing a commercial version 142One step forward, two steps back 143

Applications: the larger web 147Salt of the earth: Kharagoda 147Large-scale cooking in rural areas 164Green brick drying 166Beas: gasifier for community cooking 166Hot water for hotels 170Gasifiers for midday meals 171

Gasifier-based cremation 173Gasifiers for drying rubber 182

Taking stock 186Technology development and dissemination 186Potential for gasifier technology—manufacturers’ views 190Future potential and challenges 192

THE WAY FORWARD 195

ANNEXURES: TECHNOLOGY SOLUTIONS FOR SERICULTURE 201

Annexure 1: Overview of sericulture 203History of silk 203State presence in the indian silk industry 205

Central Silk Board 206Central Silk Technological Research Institute 206Central Sericultural Research and Training Institute 206Cocoon markets 207Silk exchanges 207

Making raw silk from cocoons—process 208Rearing cocoons 208Reeling the cocoons 209

Annexure 2: Field survey of silk reeling ovens 213Energy audits 217

Annexure 3: The Hindupur experience 222From lab to field 222

Mark 0: proof of concept 222Mark 1: laboratory model 225Mark 1: field model 226

Annexure 4: The Ramanagaram experience 236From field to commercial model 236

Mark 2: improved field model 236Mark 3: industrial prototype 244Mark 4: commercial prototype 249

viii

Annexure 5: The Siddlaghatta experience 252Background 252Technology development 254

Mark 0 254Mark 0-F 254

BIBLIOGRAPHY 261

CONTRIBUTORS 271

ABBREVIATIONS 279

India annually produces about 400 million tonnes of a variety of biomass,which on a tonnage basis is on a scale comparable with coal production.Most of these biomass materials are consumed for heat generation, as hasbeen the practice since the dawn of human history.

The single largest use of biomass in India is for cooking and other house-hold purposes. Besides, there are over one million SMiEs (small and microenterprises) that burn biomass fuels. However, unlike coal, which is usedwith conversion efficiencies of over 80% in boilers and other equipment, theconversion efficiency with biomass is still quite low at about 10%. The resultis a huge wastage of an important natural resource. Also, biomass combus-tion in traditional devices produces smoke, carbon monoxide, and otherhealth-damaging emissions. It is thus imperative to use the available biomassresources more efficiently and in a clean manner. Gasification technologyoffers considerable scope for achieving this goal.

Biomass gasification as a technology emerged during the Industrial Revo-lution, and was successfully used for running automobiles, lighting publicplaces, cooking in urban households, and generating power during theSecond World War, largely in European countries. It re-emerged in the wakeof the oil crisis in the 1970s in India and in a few other developing countriessuch as the Philippines; the technology’s main application at that stage wasseen in small-scale power generation for purposes such as irrigation pump-ing. In recent years, however, interest has been rekindled in biomass gasifica-tion, particularly among developing countries that are rich in biomassresources and that find themselves caught between rising prices of fossilfuels on the one hand and development needs on the other.

TERI began to work in the field of gasification in 1984 in a small way at itsField Research Unit at Pondicherry, and later organized and expanded its

FOREWORD

x

activities in Delhi. A gasifier demonstration unit was set up on a lawn in thecapital’s posh Jorbagh area; a car garage served as a small workshop; and anattached bathroom was converted into a fuel-testing lab! With initial helpfrom MNRE (Ministry of New and Renewable Energy), research and fieldactivities were implemented in the village of Dhanawas in Haryana.

A number of exploratory activities were undertaken to introduce thetechnology as a fuelwood-saving measure in plantations (such as for carda-mom curing, tea drying, and so on), and as a replacement for furnace oilused in boilers in small industries (herb-based products, tobacco processing,etc.). It was apparent that, besides applications in small power-generatingsystems, judicious use of biomass gasification technology could result infuelwood savings – with implications of reduced deforestation – as well assavings in furnace oil/diesel/LPG (liquefied petroleum gas)—with implica-tions of increased energy security.

During the same period, SDC (Swiss Agency for Development and Coop-eration) was active in the sericulture sector. SDC was supporting efforts bythe government to improve mulberry farming and cocoon rearing practices,and was also helping in the promotion of an improved silk reeling oven. Silkreeling units operated with very low profit margins and consumed hugequantities of fuelwood, and SDC was keen on exploring the possibility ofusing energy-efficient technology to reduce fuelwood consumption andincrease the profitability of silk reeling units. Given their commonality ofinterests, it was natural for SDC and TERI to join hands in developingenergy-efficient gasifier-based systems for the silk reeling industry.

Similarly, from the early 1990s, SDC was actively supporting efforts tobring about rural development in Sikkim—a state where the cultivation andprocessing of large cardamom is a major economic activity. The curing oflarge cardamom consumes huge amounts of firewood, and TERI’s experiencein developing efficient methods of cardamom curing in southern India againmade it natural for the two organizations to work together in developing awood gasifier for large cardamom curing in Sikkim.

These two early joint initiatives by SDC and TERI greatly helped insolving issues related to the introduction and integration of a modern tech-nology such as gasification with traditional sectors such as silk reeling andcardamom curing. Besides helping in the maturing of gasifier technology forheat applications, a methodology was evolved to mobilize the efforts ofseveral actors such as reelers, industrial design experts, and silk expertsthrough competence pooling. These two interventions helped TERI inwidening the scope of installing gasifiers for a number of other

Foreword

applications—ranging from sweet-making to steel re-rolling, chemicalprocessing to community cooking, crematoria to crumb rubber drying. TERI’sinteractions with entrepreneurs, manufacturers, government officials, NGOs,and others have helped in creating awareness about the potential benefitsoffered by biomass gasification in all kinds of other SMiE applications.

Today, there are eight manufacturers licensed and trained by TERI tomake gasifiers, and over 350 gasifier systems for diverse applications havebeen installed in the field in different parts of the country with a cumulativecapacity of over 14 MWth (megawatts thermal). These achievements havebeen possible thanks to the support extended by SDC and the great flexibilityit has shown in the course of TERI’s work.

A very important lesson TERI has learned is that to promote gasifiertechnology among traditional, resource-poor SMiEs, it is essential to forgebonds of trust and cooperation with the owners. This requires extensive andsustained work with NGOs and other community-level organizations. Inother words, the technological efforts have to be accompanied by effortsaimed at techno-social integration or TSI. TERI is pursuing this strategy in itsongoing work with ‘puffed rice’ makers in Karnataka. TERI also recognizesthe importance of building bridges of cooperation with governmental institu-tions, particularly in SMiE areas such as sericulture where state-ownedbodies exercise considerable influence on technologies as well as markets.

In today’s rapidly globalizing economy, the SMiE sector must constantlyovercome new challenges – in terms of better technology, higher operationalefficiency, increased profitability, improved product quality – in order tosurvive. To build upon the wealth of experience gained during the pastdecade, in 2005 TERI and SDC launched an initiative titled CoSMiLE (Com-petence Network for Small and Micro Learning Enterprises). CoSMiLEbrings the various interventions by SDC and TERI in the SMiE sector under acommon umbrella. In essence, CoSMiLE is a dynamic and informal network,comprising players bound together by a keenness to learn and share knowl-edge in order to bring about technological improvement and socio-economicdevelopment in the SMiE sector. In the years to come, efforts will be madethrough CoSMiLE to encourage widespread adoption of clean, energy-efficient technologies such as biomass gasifiers and thereby bring socio-economic benefits to those who depend on SMiEs for their livelihood.

R K PachauriDirector-General, TERI

Foreword xi

The SDC (Swiss Agency for Development and Cooperation) has been work-ing in India since 1961. SDC’s focus has been on building and nurturinglong-term partnerships with local organizations to bring about lasting socio-economic development among marginalized sections of the community.Reflecting this aim, in 1987 SDC began to work in sericulture—a field thatprovides livelihood to vast numbers of resource-poor people, particularly inrural areas. Although its work primarily focused on the ‘pre-cocoon’ areas ofsericulture, SDC recognized that there was also a great need to help silkreeling units, which operated with extremely lean profit margins and de-pended on low-efficiency traditional technologies that consumed largequantities of fuelwood.

In 1991, SDC established a Global Environment Programme (GEP) tosupport developing countries in implementing measures aimed at protectingthe global environment. SDC India saw GEP as an opportunity to use clean,energy-efficient technology to reduce greenhouse gas emissions as well asimprove the profitability of the SMiE (small and micro enterprises) sector—including silk reeling units. At that time, TERI (The Energy and ResourcesInstitute) was the leading institution in India working in the field of energyefficiency. Also, TERI had been working since 1984 on development andpromotion of biomass gasifier technology for a variety of applications—thermal as well as power. Therefore under GEP, SDC supported an actionresearch project by TERI to assess the potential for enhancing the energyefficiency of traditional silk reeling units in south India, and to developbiomass gasifier technology for the purpose. With the intervention showingpromise, SDC sponsored a long-term action research project by TERI thatwas in due course merged with the ‘SERI 2000’ programme for India’ssericulture sector.

PREFACE

xiv

Later, SDC sanctioned another study by TERI of the traditional bhattisystem that was being used for curing large cardamom in Sikkim. This wasfollowed by an action research programme under which TERI developed anappropriate gasifier-based system for large cardamom curing that reducedfuelwood consumption, cut down emissions, and also enhanced the qualityof the cured cardamom.

Although technology development and demonstration was foreseen as anentry point to gain credibility in the SMiE sector, these interventions havenow become more holistic in nature. After the action research period of1995–2000, the second phase of TERI–SDC collaboration (which started in2000 and extended till 2003) was devoted to strengthen TERI’s capabilitiesfor policy research through commissioning studies in the areas of ruralenergy, biomass-based industries, training delivery and outreach. During thisphase, several clusters were identified in Rajasthan and Karnataka for inter-ventions aimed at development and promotion of cleaner biomass energysystems.

Working with SMiE units was not easy. One of the main challenges wasthe lack of data on SMiE units and their operations. Another challenge wasthat SMiE units are reluctant to consider new ideas, wary about changingtheir ways of doing things. Even after the improved technologies were suc-cessfully demonstrated, their acceptance was inhibited by these walls ofwariness. Low priority was given to energy and environmental issues at theunit level; this hindered replication of the improved technologies. All thiswas compounded by recessionary trends in the Indian industry during thisperiod and the threat to the SMiE sector posed by cheap imports.

Despite these challenges, the project has been successful in developingbiomass gasifiers for a large number of ‘offshoot’ applications such as fabricdyeing, community cooking, rubber drying, steel re-rolling, and cremato-ria—in India as well as in neighbouring countries. SDC did not directly fundTERI in these offshoot projects, yet it has facilitated TERI’s efforts by givingit the space and freedom to design and develop the required gasifier systems.The web of applications is widening—although the spread of gasifier-basedtechnology depends to a large extent on pricing policies with regard topetroleum-based fuels such as diesel and LPG (liquefied petroleum gas).

This book is a process document; a brief, non-technical account of theprocess by which SDC and TERI worked in partnership to successfullydevelop and demonstrate energy-efficient and environmentally-friendlybiomass gasifier systems for heat applications in SMiEs, and the measurestaken to replicate the systems in other applications throughout the country. It

Preface

highlights the participatory approach to develop technological solutions forSMiEs, the problems encountered and their resolution, as well as socio-economic issues that have had to be confronted and tackled. It describesthe experiences of project teams and other stakeholders in the field, anddiscusses both their achievements and their setbacks—for lessons may bedrawn from these by future researchers and others interested in the field.

This book is primarily intended as a guide/reference document forresearchers, NGOs, academic institutions, donor organizations, policy-makers and others who might be interested in development and dissemina-tion of cleaner biomass technologies for low capacity end-users in SMiEs inIndia and in other developing countries.

Veena Joshi Jean-Bernard DuboisFocus-in-Charge Deputy HeadRural Energy and Housing Natural Resources and EnvironmentSDC, New Delhi SDC, Berne

Preface xv

INTRODUCTION

SMALL AND MICRO ENTERPRISES IN INDIA

In India, small and micro enterprises or SMiEs comprise a wide variety ofunits, ranging from tiny artisan-based cottage industries and householdenterprises to small-scale manufacturing firms. There is great diversityamong them—in their patterns of ownership, organizational structures,technologies, financial status, and other characteristics. However, SMiEs dohave a few common features as well. In general, an SMiE is managed by itsowner(s) in a personalized way; it has a relatively small share of the marketin financial terms; and its small and independent nature makes it relativelyfree from outside control in decision-making. SMiE operators and workersusually acquire their skills by tradition; these skills are transmitted throughthe generations with minimal change or up-gradation.

The SMiE sector plays a vital role in the Indianeconomy. It manufactures a vast range of prod-ucts, mobilizes local capital and skills, andthereby provides the impetus for growth anddevelopment, particularly in rural areas and small towns. The SMiE sector isnext only to agriculture in providing employment; in 2003–04, small-scaleindustries alone employed around 27 million people.1

SMiEs are found in clusters all over India. There are many historical rea-sons for the clustering of units—availability of fuels and raw materials,access to pools of semi-skilled labour, proximity to markets, and so on.

1 Ministry of Small-scale Industries. 2005. Annual Report, 2004/05. New Delhi: Ministry of Small-scale Industries, Government of India.

SMiEs form the backboneof the Indian economy

2 A process story on biomass gasifiers for heat applications in SMiEs

Besides an estimated 2000 artisan-based rural SMiE clusters, there are anestimated 140 clusters within or in the periphery of urban areas in India,with at least 100 registered units in each. These urban SMiE clusters varysignificantly in size; some clusters are so large that they account for 70%–80%of the entire country’s production of a particular item. For example,Ludhiana produces 95% of India’s woollen hosiery, 85% of sewing machinecomponents, 60% of its bicycles and bicycle-parts, and accounts for over halfof Punjab’s total exports. Similarly, Tirupur in Tamil Nadu has thousands ofsmall-scale units engaged in spinning, weaving, and dyeing of cotton gar-ments; this city alone accounts for around 60% of India’s total cotton knit-wear exports.2

In general, cost factors weigh much more for anSMiE owner than issues such as energy efficiencyand pollution. Hence, an SMiE uses the cheapestfuels that are available in its locality. Because ofthe easy availability of biomass such as fuelwood,leaves, husks, and assorted agricultural wastes, almost all rural SMiEs burnfuelwood and other biomass for energy. For instance, each year an estimated438 000 tonnes of fuelwood are used up for curing tobacco leaf; 250 000tonnes for tea drying; and 100 000 tonnes for silk reeling. Urban SMiEs tooburn fuelwood; around 1.72 million tonnes of fuelwood are used up eachyear by fabric printing units.3 Coal and petroleum-based fuels such as kero-sene and diesel are used mainly by urban SMiEs, because these fuels aremuch easier to obtain in urban areas than in rural areas. SMiEs also burnhighly polluting low-grade fuels such as ‘spent’ machine oils, lubricants, andused tyres.

THE PROTECTED YEARS

Recognizing the vital role played by SMiEs in production of goods and inemployment generation, the Indian government took various measures from

2 Albu M. 1997. Technological learning and Innovation in industrial clusters in the South. PaperNo. 7, Science Policy Research Unit. Brighton, U.K: University of Sussex.

3 Kishore VVN et al. 2004. Biomass energy technologies for rural infrastructure and villagepower—opportunities and challenges in the context of global climate change concerns. EnergyPolicy 32(2004), 801–810.

Costs weigh much morefor SMiEs than issuessuch as pollution and

energy efficiency

Introduction 3

independence onwards to provide fiscal, credit, marketing, and infrastructuresupport to the SMiE sector—even as the nation followed a path of industri-alization that emphasized the building of heavy industries, primarily in thepublic sector. From 1967 onwards, the government reserved certain items forexclusive manufacture by small-scale industries. Forty-seven items werereserved to start with: that number has grown over the years, and at present,there are over 800 items reserved for the small-scale industrial sector—ranging from wood and leather products to glass and ceramics; from rubber,paper, and fabric products to spices, foods, and electrical appliances. Thanksto the government’s support policies, the small-scale industrial sector todayforms the backbone of India’s manufacturing capacity. It contributes overhalf of India’s entire industrial production in value-addition terms, andaccount for one-third of export revenues.

But the government’s policies have proved to be a mixed blessing forSMiEs. The policies were primarily intended to ensure the survival of SMiEs,to protect the jobs of those employed in them, and to increase the overallproduction of the sector (rather than the productiv-ity of individual units) to cater to the demands of agrowing indigenous market. Scant attention waspaid by the state to improve the operating practicesof units, or to help them modernize their technolo-gies through exchange of ideas or by indigenous R&D (research and develop-ment) efforts. In the technical institutes and engineering colleges, there is alack of interest in studying small-scale industrial processes such as drying ofagro-products and food processing—even though these activities are of greatsocio-economic importance (in terms of revenue and employment genera-tion), use up huge amounts of energy, and generate vast amounts of pollut-ants.

On the one hand, SMiEs were insulated against healthy competition frommedium and large-scale enterprises, within and outside India; on the other,they were unable to access information on technological advances madeelsewhere, and had neither the incentives nor the resources to conduct theirown R&D. Outdated and inefficient technologies, compounded by poormanagement practices and declining labour productivity, steadily ate awaytheir profits and slowed down industrial growth. By the early 1990s, theSMiE sector suffered from widespread technological obsolescence, lowproductivity, and an inability to access or adopt better technologies.

Protective state policieshave proved to be amixed blessing for

SMiEs


L I BERAL IZAT ION CHALLENGES

In 1991, a new Industrial Policy paved the way forliberalization of the Indian economy. Since then, themarket has been opened up in stages to individual/private entrepreneurs—Indian and foreign. The government is progressively withdrawing from thecommercial and manufacturing sectors, even as the private sector is movingin to fill the spaces vacated. Where there was state control and state mo-nopoly, there are now new opportunities for private players; where therewere fixed prices and protected markets, there is now competition and thefree play of market forces. Thus, liberalization has created new opportunitiesin trade, investment, and manufacturing for Indian and overseas investors.

However, liberalization has considerably increased the problems of theSMiE sector. The reason is simple: the new market paradigm favours thestrong and punishes the weak. For decades, the sector survived primarilybecause it had been shielded from the competitive currents of both indig-enous and global markets. Since 1991, that protective framework has steadilybeen dismantled, and now SMiEs have to face competition not only frommedium and large enterprises in India, but also from imports. In today’sliberalized economy, the survival and growth of SMiEs depend on theirability to become competitive: that is, to improve productivity and quality ofproducts, and to develop new products to keep up with changing demands.This in turn means that they must use better technologies and methods ofoperation. But these are precisely the tasks that they are incapable of doingon their own. Having functioned for five decades within an overly protectiveeconomic and industrial framework, they lack the flexibility, technical capac-ity, and resources to change the ways in which they function.

The environmental imperative

The SMiE sector also has to contend with a new challenge—environmentalregulation. SMiEs largely use low-grade fossil fuels or biomass such asfuelwood for energy. These fuels are burned using inefficient equipment andtechnology, releasing gases that are harmful to health as well as to Earth’satmosphere. The last two decades have broughta new and growing awareness across the worldabout environmental pollution and its adverseeffects—particularly after the United NationsFramework Convention on Climate Change or

The liberalized marketfavours the strong and

punishes the weak

SMiEs do not have thetechnical ability or resources

to modify their inefficienttechnologies

Introduction 5

UNFCCC held at Rio de Janeiro in 1992. India has joined other nations inenacting laws to curb pollution. However, SMiEs do not have the technicalability or the resources to modify/change their inefficient technologies, or toinstall pollution control equipment to meet the standards set by the newlaws. Thus, the threat of closure constantly looms large over them.

Clearly, SMiEs need help to survive in today’s liberalized economy. Clo-sure of these units would threaten the very existence of millions of peoplewho depend on them for their livelihood, particularly in rural areas. It isagainst this backdrop that two organizations—SDC (Swiss Agency for Devel-opment and Cooperation) and TERI (The Energy and Resources Institute)4—decided to intervene in partnership in the SMiE sector.

A PARTNERSHIP I S FORGED

SDC—human and institutional development

SDC is part of the Swiss Federal Department of Foreign Affairs. SDC focuseson poverty alleviation. Towards this mission, it supports programmes thatpromote good governance, helps improve working conditions, aims at solv-ing environmental problems, and provides better health care and educationalopportunities for the most disadvantaged sections of society.

SDC has worked in India since 1963. Initially, SDC focused on the areas oflivestock and animal husbandry; later, its interventions expanded to covervocational training and SMiEs. In 1987, it began to work in the field ofsericulture. From the outset, SDC’s interventions paid great attention totraining and teamwork, and in ensuring the participation of local people inprojects to make them sustainable. In the course ofits work in India, SDC has clearly outlined fourareas: poverty, civil society, human rights, andsustainable use of natural resources. It recognizesthat these areas are closely linked to one another;that developments in one have an impact on theother areas; and that all the areas together have a fundamental role to play inaddressing the issue of sustainable development.

From 1991 onwards, SDC became particularly concerned with the effectsof liberalization on India’s poor. It recognized that in an increasingly market-driven scenario, even as government withdraws from key sectors of the

4 Formerly, the Tata Energy Research Institute

SDC has beenparticularly concerned

with the effects ofliberalization on the

poor


economy, NGOs (non-governmental organizations) and private institutionsplay an important role in the development process. Interventions to alleviatepoverty successfully, therefore, require partnerships with NGOs and otherprivate bodies. Hence, SDC has introduced the principles of HID (humanand institutional development) into all its interventions. In essence, HIDaims at building strong partnerships with individuals, organizations andinstitutions, and in developing and enhancing partners’ skills through moti-vation, training, access to information, and exchange of ideas.

Global Environment Programme

In 1991 the Swiss Parliament sanctioned a special grant to SDC on the occa-sion of Switzerland’s 700th anniversary. One of the aims of the grant was toaddress global environmental problems. SDC accordingly set up a GlobalEnvironment Programme or GEP to support developing countries in further-ing the goals of the UNFCCC. Under the grant, SDC initiated a study andcooperation programme in India for the phasing out of CFCs(chlorofluorocarbons) in the refrigeration sector. It also co-financed a marketdevelopment programme for photovoltaics along with the World Bank.

SDC recognized that there existed enormous potential for energy conser-vation and environmental protection in the Indian small-scale industrialsector. It thereupon sought and identified two institutional partners to imple-ment its energy–environment programmes in the country: TERI and DA(Development Alternatives). Both TERI and DA are NGOs based in Delhi.

TERI—global vision, local focus

TERI was established in 1974 through a corpus of a few Tata Group compa-nies. Initially, TERI funded and supported research in the fields of energyefficiency and renewable energies in academic institutions. Thereafter, itsactivities expanded to hardware research in renewable and rural energies(first at its Field Research Unit in Pondicherry, and later at its research facil-ity in Gual Pahari, near Delhi), and to documentation and dissemination ofenergy-related information. TERI works at both micro- and macro-levels. Forinstance, it provides environment-friendly solutions to rural energy prob-lems; helps forest conservation efforts by local communities; promotes en-ergy efficiency in Indian industry; shapes the development of the Indian oiland gas sector; finds ways to combat urban air pollution; and tackles issuesrelated to global climate change.

Introduction 7

Among other achievements, TERI has acquiredconsiderable expertise in conducting energy auditsin various industrial sectors. The institute has highlyskilled human resources equipped with state-of-the-art instrumentation and software for gathering andanalysing energy-related data.

Like SDC, TERI strives to make its programmesparticipatory, that is, they are undertaken with thefull involvement of local communities, and they taplocal skills and traditional wisdom in order to ensure their adoption andsuccess. TERI, too, lays great emphasis on training, capacity building, andeducation. It clearly recognizes the links between degradation and depletionof natural resources on the one hand, and increase in poverty on the other. Itsactivities are guided by the principle that the development process cansucceed, and be made sustainable, only through the efficient utilization ofenergy, sustainable use of natural resources, large-scale adoption of renew-able energy technologies, and reduction of all forms of waste.

By 1992, TERI had worked for nearly two decades in the field of energy,environment, and natural resources conservation. It was the largest develop-ing-country institution working to move human society towards a sustain-able future. It had unique skills in conducting energy audits. Above all, themodel of development pursued by TERI corresponded well with the oneenvisaged by SDC. Thus, SDC decided to intervene in the fields of energyand environment in India in partnership with TERI.

THE MACRO -LEVEL STUDY

In 1992, SDC initiated a study of energy consumption patterns in the IndianSMiE sector in order to help identify areas for intervention. Pierre Jaboyedofffrom Sorane SA, Switzerland, was mandated as an international consultantto assist SDC in coordinating the exercise. SDC collaborated with TERI inconducting energy sector studies in SMiE areas such asfoundries, glass making, and silk reeling. SDC hadalready been working with DA in the building mate-rials sub-sector, which included the brick-makingindustry.

The macro-level study revealed that the energyefficiency of Indian SMiEs (that is, the efficiencywith which they extract and use energy from

TERI focuses onenergy efficiency and

sustainabledevelopment…TERIrecognizes the link

between poverty anddepletion of natural

resources

Many SMiEs have lowenergy efficiencies.

They are also energyintensive: the cost offuel makes up a largeportion of production

cost


fuels) is much lower than that of their counterparts in industrialized nations.Besides having low energy efficiencies, many SMiEs are highly energy-intensive: that is, the cost of fuel makes up a large portion of production cost.Examples include foundries, food-processing units, forging units, and indus-tries that manufacture glass, ceramics, and bricks. At the same time, SMiEsemploy large numbers of workers. If these units are to remain competitive, itis essential to find ways to increase their energy efficiency, and therebyreduce the burden of fuel costs.

But herein lies a challenge. To increase energy efficiency, an SMiE mustmake changes in its technology and operating practices. But such changesrequire the investment of time and money—both scarce resources in thesmall-scale sector! Unlike medium or large-scale units, small-scale units havelimited financial and human resources, and they operate with slender profitmargins. They might show willingness to adopt change—provided thechange offers benefits in terms of increased productivity and profits. Butthey do not have the capacity or resources to initiate or invest in change.

The scope for intervention

SDC recognized this challenge faced by the SMiE sector, and saw in it anopportunity for intervention. Improving the energy efficiency of small-scaleunits—particularly those in energy-intensive areas—would be the best wayto increase their productivity and profitability. It would also translate intoreduced consumption of non-renewable fossil fuels and wood, and bringdown the emissions of greenhouse gases and other pollutants by the units.

How could energy efficiency be increased? The answers would varyamong different SMiE sub-sectors, and indeed among units within a particu-lar sub-sector. Better methods could be found toburn a fuel and to use its energy; alternate fuelsmight be identified, that were readily available andthat yielded the same amount of energy at little orno extra cost and with less pollution; systems couldbe devised to recover and reuse heat energy gener-ated during the manufacturing process; and so on.Whatever be the mechanism, increased energy efficiency would translate intoa higher yield of product for the same amount of fuel consumed, and therebyimprove a unit’s performance—in terms of resource consumption, environ-mental impact, and productivity.

However, it was clear that an intervention to improve energy efficiencywould be sustainable only if it addressed the following imperatives:

SDC recognized thechallenges faced by theSMiE sector, and the

opportunity tointervene with

improved technologies

Introduction 9

� the SMiEs must be enabled to meet environmental laws and regulations;� they must be made economically competitive, particularly in energy-

intensive categories; and� the quality of their products must be upgraded, and their markets must be

preserved/enhanced.

SCREENING WORKSHOP , DECEMBER 1994

To discuss the results of the macro-level study and finalize its strategy forintervention in the energy sector, SDC organized a ‘Screening Workshop’ on8–9 December 1994 in New Delhi in collaboration with TERI. The workshopbrought together scientists, policy-makers, government representatives,NGOs, representatives of industrial associations, and experts in diversefields, ranging from biofuels, foundries, and forestry to renewable energy,glass-making, and silk.

The workshop adopted a unique approach. First, a total of 11 options forintervention in the energy sector were presented to an Advisory Panel,whose members represented the collective wisdom in India on policy issuesrelated to energy. Each Panel member examined and ranked the options inorder of preference. The options were: foundries (Agra); glass industries(Firozabad); silk reeling ovens; alternate building materials; brick kilns;building energy efficiency; solar photovoltaics; solar water heaters; oil fromJatropha curcas (‘bio-diesel’); diesel pumpsets; and biomass.

Thereafter, sectoral experts used the rankings of the Advisory Panel todiscuss the options in detail, and to suggest to SDC the possible areas foraction. Certain criteria were applied in order to identify the best areas forinterventions. The criteria included energy intensity; potential for energysavings; potential for replication; importance of the SMiE sub-sector con-cerned, particularly in terms of the number of workers employed and theirsocio-economic status; non-duplication of efforts; techno-economic viabilityof measures proposed; compatibility with SDC’s India Country Programme;and potential partners, and their ability and willingness to cooperate.

Finally, based on the participants’ recommendations, SDC selected thefollowing four areas in which to intervene with technologies designed toimprove energy efficiency, environmental performance, and productivity:1 foundries;2 sericulture (with wood gasifiers for improving thermal efficiency of silk-

reeling ovens;3 glass industries; and4 brick manufacture.


This book describes how the project intervened in the field of sericulturewith gasifier-based silk reeling ovens, and went on to develop biomassgasifiers for a large number of other thermal applications—ranging fromchemical extraction to large cardamom drying, from community cooking tocrematoria.

GETT ING STARTED

While structuring their interventions and drawing up their work plans, theproject had to consider a few vital issues.

Cluster-level intervention

At what level should the interventions be undertaken? On a national scale?Or at unit level? If so, where?

A list of ‘dos’ and ‘don’ts’suggested by the Screening Workshop

for the sericulture sub-sector

Introduction 11

The idea to intervene at cluster-level sprang from the Screening Work-shop. Units producing similar goods, and possessing great similarity inlevels of technology and operating practices, are found in close proximitywithin a typical SMiE cluster. Therefore, it was felt that the best way tospread an improved technology would be to first demonstrate its benefits toa few representative units in a cluster. Ideally, these units should be chosenby local industrial associations. Where such formal groups did not exist, theunits should be identified by other bodies familiar with the cluster profile(such as district industries centres). Once the selected units realized theadvantages of the new technology and adopted it, other units in the clusterwould tend to follow suit—and dissemination of the technology would berapid and effective. Therefore, each intervention took place initially at clusterlevel.

Finding the right technology

Which technology is best suited for a particular sub-sector? Obviously, itshould be a technology that uses less energy and results in less pollutionthan the existing technology. It should retain the existing quality of theproduct, and if possible improve upon it. Yet, the answer is not as simple asfinding and importing the best technology available in the world that meetsthese requirements. The selected technology must be acceptable to localpeople; it must be easy for them to use (perhaps with training); and it mustsuit local conditions.

In India, unemployment is high and capital is scarce. Therefore, the new/improved technology should be affordable; and it should minimize theimpact on the existing workforce in terms of loss ofjobs. It should not depend on external inputs or non-local resources to function, except at the initial stages.Like existing technologies, it too should work on fuelsand raw materials that are locally and readily availableat affordable prices. As far as possible, it should resem-ble the technology already being used in the area; forthis would help make it acceptable to and easily adapt-able by local people.

Therefore, in selecting a technology for intervention, existing technologieshad to be evaluated —in India and elsewhere—to identify those that could beadapted/modified to meet the standards set for energy efficiency and envi-ronmental performance. Thereafter, from among the available options, the

The selectedtechnologies must

be acceptable tolocal people, easyto use, and suitlocal conditions


most appropriate one, that is, the one most suited to adaptation to meet localneeds and conditions, had to be selected and developed for demonstrationand eventual dissemination.

Participatory technology

To succeed in the long-term, a technology should not only be appropriate. Asfar as possible it must build on, and be built upon, the skills and knowledgeof local people; it should be adapted/developed with their full participation.This approach to technology development gives the beneficiaries a sense of‘ownership’ over the technology; they become confident in its use. By itsvery nature, participatory technology is developed on the basis of collectivelearning, sharing of ideas and traditional wisdom, and R&D based on com-munity needs. Because it works closely with the community and at a deeplevel of society, participatory technology has the potential to bring aboutprofound social change.

To ensure the participatory development of technologies, the projectteams worked closely with unit owners and workers, industry associations,local government institutions, NGOs, and other bodies at the field level.

Capacity building: key to sustainability

The success of any intervention is measured by its sustainability. This in turndepends on the capacity of the recipients to absorb the new/improved tech-nology. The recipients should be able to continue to adapt and innovate thetechnology long after the intervention project has ended —to cope with andovercome whatever challenges the future might bring. Here, it is importantto recognize that technology is not just about equipment and tools. It is apackage of knowledge that enables the recipients to use the equipment andtools to produce specific products of specific quality.

In other words, it is not enough merely to develop a new technology andto demonstrate its benefits. Local people should be given the informationand skills that they require to use the technology in the long-term. Theyshould learn the benefits of exchanging ideas and sharing experiences, andhow this would help them manage changes without depending on externalsources for help. Capacity building, therefore, formed a vital component ofthe project’s interventions.

Introduction 13

STRUCTURING THE INTERVENT IONS

Having considered all the above issues, SDC and TERI structured eachintervention as a package of parallel and ongoing measures that are listedbelow.� Perform energy audits (Box 1). Learn, during the energy audits, about

things beyond energy—such as existing operating practices, quality offuel, and so on.

� Search for suitable solutions—to achieve the benchmarks set for energyefficiency and environmental performance.

� Develop and demonstrate an improved technology, in terms of energy andenvironmental performance and other parameters. Fine-tune the devel-oped technology for wider dissemination.

� Help other units to upgrade and adapt their existing technologies asrequired.

� Seed the markets, that is, help make the technologies available via localsuppliers; promote measures to reduce their costs and increase theiruptake.

� Increase the number of partners and collaborators in the field, andstrengthen their capabilities by ongoing HID so as to promote dissemina-tion of the technology.

� Make efforts to establish a regular policy dialogue between various play-ers in each area (industries, institutions, government bodies, etc.).

� Conduct studies on the socio-economic conditions in the clusters con-cerned. Devise strategies for the improvement of working conditions inthe clusters.

� Identify new areas for R&D activities, for future interventions.

ACT ION RESEARCH

In each area, the project’s work followed the dynamic and cyclic pattern of‘action research’, with activities taking place in three broad and overlappingphases:1 developing a plan of action based on reconnaissance (the ‘recce’ phase);2 taking actions according to that plan (the ‘pilot’ phase); and3 assessing results of the actions, to formulate and take further action (the

‘assessment’ phase).


BOX 1Energy audit andSankey diagram

An energy audit is a kind of ‘baseline’study. It examines the pattern ofenergy use in an existing industrialprocess, and provides data oncertain parameters. These data arethen mulled over, and some or all ofthem are used as yardsticks to evalu-ate other technological options. The

Sankey diagram shows, at a glance,the amounts of input heat used upin different parts of a process(Figure 1). Thus, the Sankey diagramis a simple but powerful tool to iden-tify areas in which energy efficiencymight be improved.

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Figure 1Sankey diagram of a traditional

cottage basin oven

Introduction 15

For the sake of clarity, the various activities have been describedsequentially as far as possible in this book. In reality, though, action researchdoes not take place according to a neat timeline. Action research is a dynamicframework: a process of continuous planning, experimentation, assessment,and learning that cuts across timelines, and that involves frequent and exten-sive interplay between different phases and the players in those phases.Action research does not achieve targets and goals by linear paths, but by aseries of iterations and loops.

Competence pooling

The development of an appropriate participatory technology requires manyspecialized skills—in fields ranging from energy management to pollutioncontrol, from engineering and equipment design to training, market research,and market development. Therefore, each intervention took the shape of atechnology package that was developed and implemented by a multi-disci-plinary team, comprising experts and consultants from India and abroad,technology providers, engineers, and others (Box 2). These specialists pooledtheir competencies and adapted equipment designs and operating practicesto local conditions and to suit the requirements of the local operators.


BOX 2Competence pooling—putting

the pieces together

When the TERI teams started out ontheir interventions more than a dec-ade ago, they did have a lot of exper-tise with energy audits. Most of theseenergy audits were focused on largeand medium industries. But when theteams started analysing brick kilns,foundries, glass furnaces, and silkreeling units, they soon realized thatthe complexities of these small andmicro enterprises were no less thanthe former; often, they were evengreater.

Instead of reinventing the wheel,TERI decided to call in specific ex-perts to fill up the lack of knowledgein the many technology-related do-mains. This strategy—of ‘competencepooling’—has proven to be very effec-tive. Typically, technology specialistsare excellent in analysing and run-ning processes; but they are not veryinterested in things like energy effi-ciency. On the other hand, energyspecialists like TERI and me perhapstend to underestimate some of the

technology-related hurdles. By inter-acting closely with one another andwith the industry associations andthe pilot plant unit workers, we wereable to develop technologies adaptedto the needs of SMiEs.

The more the different compo-nents of the intervention progressed,the more specific the demands for ex-pertise became. The interventionprocess is like a puzzle. After somany years of work, it has becomeevident that for the successful com-pletion of the process, the pieces ofthe puzzle—made up of knowledgeand expertise—have to be put to-gether in the correct way. Compe-tence pooling is like many mindscoming together to move a body in achosen direction. The concept cutsacross, indeed holds together, all theinterventions by SDC and TERI in thesmall-scale sector.

Pierre JaboyedoffSorane SA

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CHARTING THE COURSE

ENERGY FROM B IOMASS

Biomass comprises a variety of carbon-containing substances derived fromliving matter. Fuelwood, twigs and leaves, agricultural residues such ashusks and stalks, vegetable oils, and animal wastes are all examples ofbiomass. These materials can be used as fuel to obtain energy. Throughouthuman history, biomass has been burned to generate heat and to provideillumination.

Only since the Industrial Revolution has the use of fossil fuels such as coaland petroleum-based products become widespread. These fuels are popularbecause they are made available at low prices. However, Earth’s stores offossil fuels are limited, i.e., they are non-renewable sources of energy. Theprices of fossil fuels usually reflect the costs of their extraction and produc-tion (exploration, mining, drilling, and refining), but they do not reflect thecosts of the environmental damage caused by these processes. Also, fossilfuels contain carbon that has been ‘locked away’ for millions of years. Whenfossil fuels are burned, the carbon released addsto the overall CO2 (carbon dioxide) content ofEarth’s atmosphere, increasing the greenhouseeffect and the threat of climate change.

In contrast, biomass is an energy source that,if sustainably managed, does not increase the CO2

content of Earth’s atmosphere. Plants absorb CO2 and store away the carbonso long as they grow. When plant-based biomass is burned, the stored carbonis released back into the atmosphere as CO2 but absorbed by other growingplants. This makes biomass a ‘CO2-neutral’ source of energy—provided ofcourse that the extraction of biomass is done in a sustainable manner.

Biomass is a renewable,CO2-neutral source ofenergy if sustainably

managed


Because plants can be regenerated again and again, biomass is also a renew-able energy source.

B IOMASS -BASED ENTERPRISES

The single largest use of biomass—particularly in developing countries suchas India—is for cooking and other household purposes. Biomass fuels suchas fuelwood, husks, shells, and other agricultural wastes also comprise themain source of energy for a great number of small-scale enterprises, particu-larly in rural and peri-urban areas. The mainreason is that in developing nations such asIndia, biomass fuels are generally cheaper thanfossil fuels. (This is not necessarily true fordeveloped nations, where the cost of fuelwoodmay be comparable to or even exceed the costsof petroleum-based fuels.) Biomass fuels in Indiaare cheap because the market for such fuels is almost entirely in the ‘infor-mal’ sector, i.e., outside any regulation by state authorities.

In India, biomass-consuming enterprises can be divided into two catego-ries described below.1 Traditional biomass-based enterprises—these are mainly cottage indus-

tries and small-scale enterprises in rural areas. They depend predomi-nantly on biomass fuels such as wood, agricultural residues (stalks,husks), and saw dust. The reason is simple: biomass is cheap in rural areascompared to fossil fuels, and it is more readily available. The biomass isused for purposes such as direct heating (for instance, in firing bricks),indirect heating (e.g., for drying of green cardamom), boiling of water(e.g., to cook cocoons to make silk), and so on.

2 New or potential biomass-based enterprises—these are medium-sized orsmall-scale enterprises that currently use fossil fuels but are willing toswitch over, at least partially, to biomass fuels that are available locally atlower prices. Examples of such ‘new/potential’ industries include textiledyeing units, crumb rubber units, and lime kilns.

Numerically, the majority of biomass-consuming enterprises are cottageindustries. According to one estimate,5 in 1995 there were an estimated

5 Srinivas S N. 2000. Biomass consumption in unorganized enterprises in India. BUN Newsletter 3.3(June 2000).

Biomass fuels comprise themain source of energy fora great number of small-scale enterprises in rural

and peri-urban India.

Charting the course 19

14.5 million unorganized enterprises in India, of which 5.05 million units(32.94%) consumed energy. Of these, around 1.82 million units burnedbiomass fuels, primarily in the form of firewood or charcoal. These unitsoften operate at household-level and function on seasonal basis (for example,the cardamom curing units in Kerala and Sikkim). The biomass fuels theyrequire are obtained locally. Data on these enterprises are scarce, mainlybecause their transactions are conducted on cash terms. What is certain isthat they provide livelihoods to a very large number of people, and henceform a vital part of India’s economy. According to a study report by UNIDO(United Nations Industrial Development Organization),6 in 1993–94 anestimated 22.42 million people worked in small-scale enterprises in the non-factory sector. Of these, 6.8 million worked in the household sector and 3.81million in ‘informal’ or unorganized units.

Huge quantities of biomass are consumed annually by biomass-basedsmall-scale enterprises in India (Table 1). For instance, each year silk-produc-ing units consume an estimated 150 000 tonnes of fuelwood (equivalent to asmany medium-sized trees) and 170 000 tonnes of loose biomass (shells,husks, cobs, and other agricultural residues). Smallbakeries, hotels, and restaurants too consume largequantities of biomass. The prevailing biomass-burning methods used in these small-scale enter-prises are very inefficient. Not only does thistranslate into a great waste of biomass resources(more trees are cut down to obtain a given amountof useful heat), but it also results in high levels ofpollution, and lowers the product quality. Biomassgasification offers immense potential to increase the amount of energy de-rived from biomass (thereby reducing fuel costs and increasing productivity);in many cases, it may improve product quality as well.

Brickmaking and silk reeling were two of the four sectors chosen by SDCand TERI in 1994 for interventions aimed at improving energy efficiency andreducing fuel consumption. These sectors were chosen not only because oftheir sizeable energy consumption, but because of the very large number ofpeople dependent on them for their livelihood. As described in this book, theinterventions with biomass gasifiers began in the silk reeling and large

6 UNIDO (United Nations Industrial Development Organization). 1997. Restructuring & Moderniza-tion of Small & Medium Enterprise (SME) Clusters in India. New Delhi: UNIDO.

Biomass gasificationcan greatly reduce fuel

costs and increaseprofitability. In many

cases, it may alsoimprove quality of

product.


TABLE 1Fuelwood using industries/

enterprises in India

Total estimated fuelwood

Specific fuelwood consumption per

Industry/enterprise consumption (approximate) annum (million tonnes)

Brickmaking 0.3–1.5 kg per brick 9.0

Cremations 300–500 kg per body 4.0

Dyeing and fabric printing 0.2 kg per metre of cloth 1.87

of saris and cloth

Vanaspati ghee 0.67 kg per kg ghee 0.63

Distilleries 0.2 kg per litre 0.6

Tea drying 1–2 kg per kg dry tea 0.5

Tobacco leaf curing 4–10 kg per kg cured tobacco 0.4

Road tarring 23 tonnes per km 0.37

Ceramic tiles 0.5 kg per tile 0.2

Silk reeling 17–25 kg per kg silk 0.15

Small cardamom curing 14–16 kg per kg dry cardamom 0.1

Rubber sheet smoking 1 kg per kg fresh latex 0.06

Large cardamom curing 7–10 kg per kg dry cardamom 0.05

Fish smoking 0.2–1.6 kg per kg fish 0.02

Source Kishore V V N. 2002. Biomass energy—challenges to the scientific community. Paper

presented at the Scientific Forum on Energy and Sustainable Societies at the 27 Triennial General

Assembly of the ICSU (International Council for Science), Rio de Janeiro, 25 September 2002.

New Delhi: The Energy and Resources Institute.

cardamom curing sectors, and later extended to many other sectors such assilk dyeing, crematoria, and crumb rubber drying.

B IOMASS GAS IF ICAT ION

In general, there are two ways to use thermal energy from biomass:� by boilers (where the biomass is burned to boil water and produce steam);

and� by gasification (where the biomass is converted into a gas that can be

burned for various applications).


Boilers are often capable of delivering higher heat efficiency thangasifiers, if properly designed. The project chose the gasification route be-cause of two reasons:� the micro-level scale of operations in enterprises such as silk reeling units;

and� the relative simplicity of gasifier technology.

Biomass gasification is a process that converts solid biomass such asfuelwood, coconut shells, etc., to combustible gases with high conversionefficiency (~ 85%). The principle is simple: biomass is burned in a limitedsupply of air (i.e., less air than is needed forcomplete burning). This converts the biomassinto an inflammable mixture of gases known asproducer gas, comprising CO (carbon monox-ide), H2 (hydrogen), and CH4 (methane), alongwith CO2 (carbon dioxide) and N2 (nitrogen).The producer gas can be led away and burnedefficiently in a controlled way to produce acleaner, steady, and high-temperature flame. Theheat generated in this way can be directly usedin a process—the ‘thermal’ application of biomass gasifier technology—or itcan be used to drive an engine to generate electric power for lighting andother purposes (Figure 2).

The principles of biomass gasification have been well known for over acentury. It was used extensively during the Second World War. Yet, fewattempts have been made anywhere in the world to develop and popularizebiomass gasifier technology on a commercial scale. The primary reason is thewidespread availability of petroleum-based fuels at low prices. Anotherreason appears to be that producer gas cannot be stored or transportedeconomically. It must be used when and where it is produced. In contrast,commercial petroleum-based fuels such as kerosene, diesel, and LPG (lique-fied petroleum gas) have well-established infrastructure for production,bottling, transportation, and distribution.

However, the ‘localized’ aspect of biomass gasification can be an advan-tage when biomass is easily available in the vicinity at prices that are farlower than petroleum-based fuels. This is precisely the environment in whicha very large proportion of biomass-based small-scale enterprises operate inIndia. The major challenges to be overcome in developing and spreadinggasifier technology are:

Few attempts have beenmade to popularize

biomass gasifiers on acommercial scale. The

main reason is the wide-spread availability of

petroleum-based fuels atlow prices.


Figure 2Types of biomass gasifiers: (a) updraft;

(b) downdraft; (c) crossdraft

(a)

(b)

(c)


� lack of applied research relevant to field applications;� lack of awareness, in industry as well as in the market, about its benefits;� lack of established network to supply, market, and service gasifier-based

equipment; and� lack of organized supply of sized and dried biomass.

EXPLORING NEW AVENUES : TERI AND GAS IF IER TECHNOLOGY

TERI began to work with biomass energy in the mid-1980s, when it startedan in-house project on the development of biomass gasifiers: first at its FieldResearch Unit at Pondicherry, and later in Delhi. In 1986, TERI got a projectfrom the DNES (Department of Non-conventional Energy Sources)7 to de-velop gasifier systems for non-wood biomass. A number of other instituteswere engaged in studying the technology at the time: notably, IIT (IndianInstitute of Technology), Delhi; IIT, Bombay; IISc (Indian Institute of Sci-ence), Bangalore; PAU (Punjab Agricultural University), Ludhiana; andSPRERI (Sardar Patel Renewable Energy Research Institute),Vallabhvidyanagar. TERI recognized the need to develop a power gasifierthat could run on a variety of biomass fuels. The DNES project was helpful indeveloping and field-testing such a system in Dhanawas, a village locatedabout 40 km from Delhi.

A detailed village-level survey was undertaken to ascertain the nature andvolume of various kinds of biomass available during the year, and to choosea site for installation of the system. In May 1990, a 7 kW (kilowatt) dual-fuelpower gasifier system attached to a briquetting machine was installed at thevillage temple in Dhanawas. It operated on non-wood biomass such asmustard stalks and other agro-residue briquettes. The gasifier providedenough energy to light up the temple complex and streetlights in the village;to run a water pump; and to make biomass briquettes that the villagers usedin place of dung-cakes. The system was successfully run till February 1996,and was then shifted to TERI’s campus at Gual Pahari as the Dhanawasproject ended.

In 1992, TERI followed up its work in Dhanawas by developing a 40 kWpower plant based on biomass gasification under a second project funded byMNES. This is a scaled-up version of the earlier smaller system. It is ideal forproviding electricity to villages that have an abundance of biomass re-

7 DNES later became MNES (Ministry of Non-conventional Energy Sources); currently, the Ministryis known as MNRE (Ministry of New and Renewable Energy).


sources, and that are not connected to the grid supply lines. It also providesbriquettes that villagers can use as fuel instead of dung or wood.

Between 1990 and 1992, TERI also undertook a turnkey project to set up athermal biomass gasifier for manufacturing CO2 (needed for making softdrinks) in Junagadh. Relatively clean CO2 is obtained by burning producergas (instead of the commonly used charcoal). The producer gas itself isobtained by the gasification of biomass. The CO2 is dissolved in a solventand later extracted in a highly pure form by heating up the solvent–CO2

mixture, using heat from the burning producer gas.In the light of TERI’s experience in the field of biomass gasification, SDC

decided to partner with TERI in exploring the use of gasifier technology toimprove energy efficiency in two biomass-burning SMiE sectors: silk reelingin the southern states of India, and large cardamom curing in the northeast-ern state of Sikkim.

THE S ILK ROUTE

Overview

Silk has been known to humankind for over 4000 years (see Annexure 1 for acomplete overview). Silk is quite unlike other fibres used to make cloth. Itneither grows in fields nor on an animal, nor is it manufactured in a factory.Instead, it is produced by a certain kind of caterpillar (or ‘silkworm’), barelythe size of a woman’s small finger. The silkworm extrudes silk in order tomake a protective cocoon around itself. The silk can be unwound in strandsfrom the cocoon by a process called silk reeling. With its exquisite softness,unearthly sheen, and great strength, silk is rightly regarded as the ‘Queen ofTextiles’.

Today, India ranks second only to China in silk production. Besides beingthe second-largest producer of silk in the world, India is also the world’slargest consumer of silk. In 2004–05, India not only produced raw silk andsilk wastes totalling 20 087 tonnes, but also imported 7948 tonnes of silk.Most of the silk is used to make saris.

The major silk-producing states in India are Karnataka, Andhra Pradesh,and Tamil Nadu. Karnataka has the largest silk reeling clusters in the coun-try—at Ramanagaram, Chennapatna, Kanakapura, and Siddlaghatta. Otherstates that produce silk include West Bengal, Orissa, Assam, MadhyaPradesh, Bihar, Maharashtra, and Jammu & Kashmir.

Around 90% of Indian silk is derived from cocoons of the mulberry silk-worm moth. In 2004–05, an estimated 171 959 hectares of land (nearly 425 000


acres) were under mulberry cultivation and produced 120 027 tonnes ofcocoons. Over 54 000 small-scale silk reeling units produced around 14 620tonnes of mulberry raw silk. The same year, the country exported silk goodsworth 28.79 billion rupees (around 640.9 million dollars).8 Besides mulberrysilk, India produces three other varieties of silk: tussar, muga, and eri. Certainkinds of raw silk yarn are also made from silk wastes, i.e., by-products ofcocoon processing.

The silk industry holds a unique place in the Indian textile sector. Unlikemost other textiles, silk is associated with high value and low volume. At thesame time, a vast number of people are dependent on the silk industry fortheir livelihood: in 2004–05, sericulture provided employment to an esti-mated 5.8 million persons from 796 685 families.9

The silk industry is based on a perishable agricultural input: namely,cocoons. In terms of quality as well as quantity, cocoons are extremely sensi-tive to weather and climatic factors. Cocoon rearing is a hands-on, labour-intensive job, and the majority of cocoon rearers are small farmers who usetraditional skills in their work. Likewise, silk reeling is mostly undertaken atthe small-scale or cottage level, and silk reeling units depend on traditionalskills and technology. The post-reeling stage involves a host of activities—weaving, dyeing, printing, and so on—that are largely undertaken by SMiEunits across the country.

State presence

The government pays great attention to sericulture because of its politicaland socio-economic importance (see Annexure 1). The Union Ministry ofTextiles has a separate wing to monitor the silk industry. The southern statesof Karnataka, Andhra Pradesh, and Tamil Nadu each have a department ofsericulture (DoS) to take care of the silk industry’s needs. Elaborate subsidyschemes are in place to benefit cocoon rearers and silk reelers. The govern-ment has set up cocoon markets in major silk reeling clusters, and silk ex-changes to enable the sale of raw silk yarn. Also, specialized institutionshave been established to provide support to the silk industry in areas rang-

8 Sourced from Table: ‘Sericultural statistics of India at a glance’. ERMIU (Economic Research andMarket Intelligence Unit), Ministry of Textiles, Government of India. (www.texmin.nic.in; websiteaccessed in July–August 2006)

9 Sourced from Table: ‘Sericultural statistics of India at a glance’. Ministry of Textiles, Government ofIndia. (www.texmin.nic.in; website accessed in July–August 2006)


ing from R&D (research and development) in silkworm production to de-signing better machinery for silk reeling units. These institutions include thefollowing:� CSB (Central Silk Board), which provides support to the silk industry by

way of R&D, extension, and training;� CSTRI (Central Silk Technological Research Institute) which undertakes

R&D activities mainly in the post-cocoon areas of the silk industry; and� CSRTI (Central Sericultural Research and Training Institute), which con-

ducts R&D primarily in the pre-cocoon areas of the silk industry.

Process—from silkworm egg to raw silk

The process of making raw silk has not changed much in the last 4000 years(Figure 3). Essentially, the process involves two broad stages:� rearing cocoons; and� reeling the cocoons to make raw silk.

Figure 3From silkworm to raw silk—

flow diagram


Each stage requires a considerable amount of time and labour anddemands great skills, patience, and care.

Rearing cocoons

Rearing is a process in which silkworm eggs are grown into cocoons in aspan of about six weeks. A major challenge for the cocoon rearer is to judgeexactly when to harvest his cocoons and send them for sale to the cocoonmarkets. If he harvests the cocoons either too early or too late, the cocoonswill spoil.

Reeling the cocoons

There are three main stages in making raw silk from cocoons:� stifling;� cooking and reeling;� re-reeling, skeining, and book-making.

The processes involved in each of these stages are described in more detailin Annexure 1.

Cooking and reeling

To reel off silk from cocoons, the cocoons are first placed in a basin contain-ing hot water. This process is called ‘cooking’; it softens the raw silk threadsfrom which the cocoons are made. The silk reeler then unwinds the threadsfrom the cocoons using a special piece of equipment that resembles a largespinning wheel. This is called a silk reel; it can be turned mechanically or byhand (Figure 4). The processed or ‘spent’ cocoons are removed from thereeling basins and sold to people who extract cruder forms of silk from them.

Reeling units fall under two main categories: charka units and cottagebasin units. In the charka unit, the same basin is used for cooking cocoonsand reeling of silk. In the cottage basin unit, cooking and reeling are carriedout in separate basins. In 1993–94 there were around 35 000 charka units and26 000 cottage basin units in use by registered reelers (Table 2).

Charka The simplest mechanism to reel silk is the traditional charka (hand-turned reel) (Figure 5). A basin of water is brought to boil by burning fuel—usually a variety of loose biomass such as groundnut shells, paddy husks,and so on—in a hearth or ‘oven’. Cocoons are placed in the water and


Figure 4The silk reel

TABLE 2Distribution of silk reeling

units in India

State No. of cottage basins No. of charkas

Karnataka 19 284 26 020

Andhra Pradesh 1 193 1 646

Tamil Nadu 3 379 590

West Bengal 1 200 6000

Madhya Pradesh 40 97

Uttar Pradesh 115 –

Jammu & Kashmir 392 –

Northeastern states 156 237

Other states 110 65

Total 25 869 34 655

Source Mande S, Pai B R, and Kishore V V N. 2000. Study of stoves used in the silk reeling indus-

try. Biomass and Bioenergy 19(2000): 51–61.


‘cooked’. Cold water is then added to reduce the water temperature, the fireis damped by reducing fuel supply to the hearth, and the silk is reeled offwith one person tending to the cocoons and another rotating the charka. Afterall the cocoons in the basin have been processed, the fire in the hearth ismade up again to commence the next cycle of cooking and reeling. Typically,a charka unit processes about 10 kg cocoons daily to make 1–1.5 kg of silk.

Usually, charka units operate in households. In some places, though,several charkas are set up in a row in a shed, with their reels rotated by acommon power-driven shaft (Figure 6).

Cottage basin A cottage basin unit has separate basins for cooking andreeling cocoons. Typically, the unit has an ‘oven’ comprising a masonrystructure of convenient height in which four to six cooking basins—usuallymade of copper or aluminium—are embedded in rows. The cocoons arecooked in these basins, and then taken across to the reeling basins. The ovenis provided with an ash pit, a grate, and a chimney for the flue gases to exit.A large water drum is embedded in the path of the flue gases to supply hotwater to the reeling basins. In effect, the water drum acts as a heat recoverysystem (Figure 7). Usually, fuelwood is burned in the oven to supply heat.

Figure 5Charka oven


Figure 6Several charka ovens with common

power-driven shaft for reeling

Figure 7Traditional cottage basin oven


Cottage basin units are generally much larger than charka units. A typicalcottage basin unit employs about 20–25 persons: six for cooking cocoons, 12for reeling silk, and the rest for tasks such as tending to the fires, watermanagement, collection of cocoons and waste silk, re-reeling, and skeining.A typical cottage basin unit having 12 reeling basins processes 90–120 kgcocoons daily, and produces around 9–12 kg silk.

Silk reeling units: field realities

Workers and wages

Over two million persons make up the workforce in silk reeling units. Themajority of the workforce is made up of women. This is primarily becausegreat deftness is needed in handling the cocoons, and in gathering andplacing the fine silk threads during the process of reeling. The women usu-ally learn their skills by tradition.

A certain minimum output is always demanded from the workers. Notonly must they process a fixed quantity of cocoons; they are also expected toobtain a certain minimum silk yield. Each day, the workers are given cocoonsin batches (say, of 5 kg each) to process into silk. Work usually begins earlyin the morning (around 0500 hours) and continues till the last batch is com-pleted (around 1500–1600 hours). Wages are calculated on a batch-wise basisand vary from 65 rupees per day for cocoon cookers to 80–100 rupees perday for reelers and re-reelers (2005 rates). During festival seasons, food issupplied along with small additional wages if the workers process an extrabatch. Several reelers pay in advance to retain their workforce.

Reelers have a few loosely organized local associations. Workers do nothave unions to present their collective views and problems, nor are thereother institutions such as workers’ cooperatives to help them obtain supportin terms of finance, child care, housing, and so on.

Health problems

The working environment in reeling units is poor. Workers are exposed tosmoke, fumes, and vapours for long periods of time. They operate amidst thereek of pupae waste, and inhale silk fibres and smoke. The health problemsfaced by workers include breathing trouble, chest pain, and blisters on thehands. Often, women bring their infants to the reeling units. The infants aretied to makeshift swings within the premises, exposing them to the smokeand other emissions generated in these units.


Profitability—a tightrope walk

The silk reeler operates with a very low profit margin (for details see Tables 4and 5 later in this text). This is because he has little or no control over eitherthe price at which he obtains cocoons (his basic raw material) or the price atwhich he can sell his finished goods (raw silk).

The quality and quantity of cocoons availablein the market, and hence their prices, vary greatlyfrom season to season, and even within a season.Government regulators fix the prices of differentgrades of cocoons, leaving the reeler with nooptions but to purchase what is available and atthe pre-determined price. Even if he is willing topay a higher price for his cocoons (thereby in-creasing his cost of production), he is not in a position to adjust the sellingprice of his raw silk to compensate for it. This is because government regula-tors at the silk exchange fix the prices of various grades of raw silk. Thereeler might get a slightly better price for his silk outside the exchange; buthere the risks are much more—especially since he has to sell his silk on creditto weavers or their agents. Besides, agent-cartels usually ‘fix’ the prices ofraw silk of various categories outside the exchange. The reelers’ problemshave been compounded by the bulk import of Chinese raw silk since 1998(Box 3).

In effect, the reeler is forced to operate in an environment that allows littleamplitude for increasing profitability; he is caught ‘between a rock and ahard place.’ (Figure 8) With no control overeither the cost of cocoons or the selling price ofhis silk, the only way he can increase his profitmargin is by cutting down his operating ex-penses. There is little scope to cut down onworkers’ wages. Fuelwood costs make up asubstantial portion of his operating expenses; but in the absence of energy-efficient technology, there is little the reeler can do to cut down this expendi-ture either. Thus, when cocoon prices rise too high, many reelers have nooption but to shut down their units.

SDC and TERI—early activities

SDC began to work in the field of sericulture in 1987. Initially, its focus wason activities aimed at improving mulberry farming and cocoon-rearing

The silk reeler operateswith a very low profit

margin…he has little or nocontrol over either the

cost price of his cocoonsor the selling price of his

raw silk

The reelers’ problems havebeen compounded by the

bulk import of Chinese rawsilk since 1998


Box 3Chinese

connection

Since October 1998, the governmenthas allowed the import of raw silkyarn. However, it has specified nei-ther the amount nor the quality of silkyarn that can be imported. Tradershave hence resorted to large-scaleimports of Chinese yarn; for, besidesits higher denier, Chinese yarn ischeaper than Indian yarn. Chineseraw silk imports rose from 3161.3tonnes in 2000–01 to 5075.8 tonnesin 2001–02. Significantly, during the

same period raw silk production bycharka and filature units inKarnataka, Andhra Pradesh andTamil Nadu fell from 6546 tonnes to5663 tonnes.10 The intense competi-tion from Chinese yarn, coupled withthe impact of fluctuation in cocoonprices and quality arising out ofdrought during the period 1999–2002, created a severe financial cri-sis in the silk reeling industry fromwhich it has yet to recover.

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10 Srinivasan G. 2002. Dumping duty on raw silk import recommended. Business Line, 22 December2002.

Figure 8The silk reeler’stightrope walk


practices. For instance, it supported the CSB and the departments ofsericulture in Andhra Pradesh and Tamil Nadu in demonstrating the viabilityof mulberry plantations in rain-fed areas. In 1989, SDC joined the CSB andvarious state departments of sericulture in a World Bank-sponsored initia-tive, the ‘National Sericulture Project’. This project aimed at developing thesericulture industry in India by improving the overall productivity of unitsand the quality of silk, by providing support services, and by increasingprivate sector involvement in the industry.

Under the National Sericulture Project, CSTRI launched a programme todevelop and promote a number of ‘economic’ cocoon cooking ovens aimed atreducing fuelwood consumption by silk producing units. The oven, origi-nally designed by Prof. S S Lokras of IISc., Bangalore, was a large improvedstove, which gave good performance and efficiency in the laboratory. TheCSTRI oven was different from the traditional oven in two respects.1 The volume of its hearth (i.e., the combustion space) was lower. This

reduced heat losses.2 The burning of wood took place in a closed chamber, which reduced the

air intake and hence flue gas losses.

These two features made the CSTRI oven capable of yielding higherenergy efficiency than the traditional oven—provided it was operated prop-erly. The CSTRI had set itself a target of selling 11 550 economic ovens by1995–96. However, by 1992–93 it had installed only 1175 ovens.

TERI’s field survey

In view of TERI’s experience in conducting research in the field of energy—particularly, energy audits—CSTRI commissioned a small study of the eco-nomic ovens. Later, an SDC mission expressed concern about the lack ofuptake of the economic ovens. TERI was thereupon commissioned by SDC tocarry out an in-depth study of the issue.

Accordingly, TERI conducted a detailed survey in 1993–94 of the variouskinds of ovens used in silk reeling units in Karnataka, Andhra Pradesh, andTamil Nadu (see Annexure 2). Such a study had never been attempted before.TERI’s pioneering survey was unique in another respect: data were gatheredfrom actual studies and measurements of processes, rather than on the basisof questionnaires.

The survey revealed that in general, all the silk reeling ovens studied—traditional charkas and cottage basins as well as CSTRI models—had verylow heat efficiencies in the range of 12%–15%. About 40% or more of the heat


supplied was being wasted in the form of hot flue gases. This showed thatthere was great potential to improve energy efficiency by recovering wasteheat. While cottage basin ovens mainly burned wood logs for heat, charkaovens burned a variety of loose biomass fuels—husks, shells, and the like—depending on their seasonal availability.

Exploring options

The results of TERI’s survey were discussed at the Screening Workshop inDecember 1994. The sustainability of silk reeling enterprises was a matter ofconcern, particularly because of the very slender profit margins on whichthey operated. The survey showed that charka ovens used a wide range ofnon-wood biomass fuels, depending on local and seasonal availability.Because of this, it would be difficult to develop a single improved-designcharka oven that could operate on a large variety of fuels with differentburning characteristics.

The survey also revealed that in contrast to charka ovens, cottage basinovens mainly burned fuelwood and broadly resembled one another indesign. A single improved-design cottage basin oven would thereforestand a better chance of adoption on a wide scale. However, analysesconducted during the survey indicated that modifying or ‘retrofitting’ theexisting (traditional) cottage basin ovens to reduce heat losses—by control-ling burning rate, recovering flue gas heat, and so on—would yield onlymarginal energy savings (about 25%), and this was not enough to make theoption economically attractive to reelers. The CSTRI’s cottage basin ovenscould save fuel costs by up to 21%, but only if the ovens were properlyconstructed and operated. As the survey revealed, reelers had altered theCSTRI ovens’ design over time, and did not adhere to the prescribed operat-ing practices.

Having considered these facts, the Screening Workshop suggested thatTERI explore the following options:� improve the thermal efficiency of the existing ovens by retrofitting to

reduce flue gas losses, control burning rate, and so on;� train the workforce in best operating practices (such as reducing water

spillages and better fire management);� aim at fuel saving and increased profitability by means of alternate sys-

tems such as an integrated gasifier system for silk reeling and pupaedrying; and

� test such alternatives at a few silk reeling units to assess their techno-economic viability.


In 1995, soon after the survey, TERI made a rough pilot of a gasifier-basedsilk reeling oven at its research facility in Gual Pahari, to demonstrate thepossibility of coupling a wood gasifier to a silk reeling unit. Dr Urs Heierli,then Head of Mission, SDC, who had agreed to come for a short visit to GualPahari, was so fascinated by the pilot model that he eventually spent severalhours at the site trying to understand the new ‘contraption’! A contract todevelop a complete system was signed within a few weeks of the firstdemonstration.

At that time TERI was also working to find ways to improve energyefficiency in the curing of cardamom—another wood-guzzling activity.As described later, TERI and SDC joined hands later on in this field ofactivity as well.

THE SP ICE ROUTE

Overview

Cardamom is the name given to the dried fruit of a perennial plant of theginger family. It is a spice that has made India famous throughout the worldsince ancient times (Box 4). There are three main varieties of cardamom.� Elettaria subulatum, commonly called ‘green cardamom’ or simply ‘carda-

mom’, is distributed from India to Malaysia.� Amomum subulatum Roxburgh, commonly known as ‘large cardamom’,

grows mainly in India and Australia.� Aframomum subulatum, called ‘Madagascar cardamom’, is found in Mada-

gascar and mainland Africa.

India is the main producer of large cardamom in the world, with about54% share in global production. Each year India produces close to 4000tonnes of this well-known spice, followed by Nepal (2500 tonnes) andBhutan (1000 tonnes) (Figure 9).

Almost 88% of Indian large cardamom (about 3850 tonnes) is produced bythe state of Sikkim alone. The hills of Sikkim provide an ideal environmentfor large cardamom cultivation; indeed, it is Sikkim’s principal cash crop.The plant grows at altitudes between 900–2000 metres (3000–6500 feet) whereannual rainfall is between 1500–3500 mm and temperature varies from 6 ºC(minimum) to 33 ºC (maximum). Because large cardamom is a shade-lovingplant, farmers prefer slopes facing north and north-east for plantations, toreduce the exposure of the plants to direct sunlight.


Box 4The royal

spice

Indian cardamom has a history thatgoes back to over 2000 years ago.Many historical Indian texts writtenbetween the 4th and 2nd centuryBCE—including the medical compen-dium ‘Charaka Samhita’ andKautilya’s famous treatise on poli-tics, the ‘Arthashastra’—refer to thespice. India traded cardamom withancient Greece, and later with the Ro-man Empire. From the 10th centuryCE onwards, Arab traders brought itinto widespread use across theworld.

Green cardamom is one of themost expensive spices by weight. It isknown as the ‘Queen of Spices’ (withblack pepper being considered the‘King’). Green cardamom plants growwild in the monsoon forests on theslopes of the Western Ghats in south-ern India, giving the region the name‘Cardamom Hills’. Till about 200years ago, wild cardamom fromIndia supplied almost the entireglobal trade. The British colonists

established cardamom plantations,and today most green cardamomcomes from cultivated sources. Thegreen seed pods are dried and usedin Asian cuisine either whole or inground form. In the Middle East,green cardamom is used to flavourboth coffee and tea. Cardamom oil isused in beverages, perfumery, andmedicines.

Large cardamom plants mainlygrow in the sub-Himalayan regions ofSikkim, Bhutan, Nepal, and theDarjeeling district of West Bengal. Itsfruit are four to six times larger thanthose of green cardamom. Large car-damom too is highly valued for its fla-vour and aroma. It is widely used inrice and meat dishes, and in bever-ages and sweets. Large cardamom isalso used in traditional medicines inIndia, China, Korea, and Vietnam. In-dia has a near-monopoly in large car-damom trade; major importers arePakistan, Afghanistan, Singapore,and the UK.

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Large cardamom is a low-input crop. Organic manure, fertilisers, andpesticides are seldom used in its cultivation. Soil moisture is usually main-tained by diverting water from seasonal springs on the upper slopes, and nospecial irrigation provisions are needed. The plants begin to flower in thethird year after planting. Flowers appear during April and May, and thecapsules mature between September and November. The quality of the cropis extremely sensitive to weather and climatic factors. The ripe capsules haveto be harvested within a span of a few days, or else they will spoil (Box 5).


Figure 9Large-cardamom production:

(a) world; (b) India

(a) (b)

Box 5Season for

spice

The harvesting season for large car-damom depends upon the altitude atwhich the plants are grown.

Altitude (feet) Harvesting time

3000–3500 mid-September3500–4500 2nd week of October

to 1st week ofNovember

4500–6500 2nd week ofNovember to 1stweek of December

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Thus, Sikkim has a very short har-vesting season for large cardamom.Unlike in south India where small car-damom capsules are plucked in 7–10 plucking rounds spread over aperiod of several months, in Sikkimthe crop is harvested in one go. An-other difference is that in south Indiaonly matured capsules are plucked,whereas in Sikkim the entire bunchof capsules is plucked (Figure 10).Later on, each capsule is separatedfrom the bunch/flower and cleanedbefore drying.


11 Mande S, Kumar A, and Kishore V V N. 1999. A study of large cardamom curing chambers inSikkim. Biomass and Bioenergy 16(1999): 463–473.

(a) (b)

Figure 10Large-cardamom plantations in Sikkim: (a) close-up of

plants; (b) plucking of matured capsule bunches from plant

There are an estimated 17 000 large cardamom plantations covering anarea of around 23 500 hectares in Sikkim. More than 85% of all plantationsbelong to small farmers whose individual holdings are less than two hec-tares11 (Figure 11). The farmers depend mainly on migrant labourers to man-age their crops. Labour is required for clearing and cleaning the soil inNovember–December; weeding during February–March and June–July; andharvesting of capsules in September–November. On average, every hectare ofplantation land requires between 110 and 130 labour-days per year. Duringthe harvesting season, the plantations provide employment to around250 000 people.

The curing process

Freshly harvested large cardamom capsules are reddish-brown in colour, andcontain up to 80% moisture and 3% volatile oils. To be safely stored, thecapsules need to be dried or ‘cured’ immediately upon harvesting to bringdown the moisture content below 10%. Traditionally, the capsules are driedusing a curing chamber called a bhatti (Figure 12).


Figure 11Large-cardamom cultivation in Sikkim:

number of holdings and area (ha – hectares)

Figure 12Traditional bhatti for curing large cardamom


A typical bhatti consists of a two-foot thick stone-walled structure, roughly square in shape, with anopening on one side to provide a hearth. Freshlyharvested large cardamom capsules are brought to thebhatti, usually in gunny bags or in bamboo baskets.The capsules are spread in a bed 10–12 inches(25–30 cm) thick on a wire mesh or bamboo mat, with the help of a bamboostave or a spoon-like wooden spreader. The mat is then placed over the bhattiand a fire is made up in the hearth, using green (freshly cut) logs that gener-ate thick smoke. The logs are obtained from trees in the vicinity (Figure 13).

Figure 13Views of the traditional large cardamom bhatti: (a) bhatti with

stone walls and wide opening for fuelwood; (b) bhatti withcemented walls and smaller opening; (c) high smoke level in

bhatti; (d) large cardamom capsules being turned over duringcuring operation

(a) (b)

(c) (d)

Ripe large cardamomcapsules have to becured immediately

upon harvesting forsafe storage


The fire is maintained in the bhatti till the drying iscomplete.

Depending upon the size of the plantation, thefarmer cures his large cardamom crop in 3–8batches. In other words, the bhatti is used only 3–8times a year. Hence, the farmer is averse to investinglarge amounts of money on a bhatti. All bhattis areconstructed with locally available materials—rocks, stones, bamboo, woodlogs—and by spending a few days’ labour costs.

The need for intervention

In practice, the bhatti system of curing has great disadvantages. The dryingprocess is very slow: it takes about 30–48 hours, depending on the bhatti’sdesign and on the logs used. This means that a lot of heat energy from theburning logs is wasted. Also, there is a lack of control over the rate of burn-ing of the wet logs. At times the fire is intense, and the flames are not uni-form and rise very high. Overheating in localized areas leads to splitting andblackening of capsules. It also results in the loss of the precious volatile oilsthat give large cardamom its unique flavour and taste. Excessive exposure tosmoke imparts a burnt, char-like smell to the oils if extracted.

The quality of large cardamom is also affected by the prevalent system oftenant farming coupled with the practice of hiring migrant farm labourers.‘The tenant farmer takes a portion of the yield as his share,’ observes aproject team member. ‘All the planting and harvesting work is done bymigrant workers from Nepal. The workers are engaged through a sardar orcontractor; the sardar pays the workers in cash or gives them small quantitiesof the harvested large cardamom. Because of this system, the workers are notreally interested in the quality of produce; their priority is to finish the workas soon as possible, collect their wages, and go back to their homes.’

Even when his harvest is good in terms of yield and quality, the farmer isnot in a position to demand a good price for his large cardamom. This isbecause the primary markets for large cardamom are in places far away fromthe plantations—in cities such as Amritsar, Jaipur, Lucknow, and Delhi. Thefarmer is therefore forced to sell his produce to agents, who have formed avery strong and well-established network centred at Singtam (Sikkim). Theseagents ‘fix’ the prices for various grades of large cardamom among them-selves, and the farmer has little option but to sell at those prices—irrespec-tive of whether or not the prices enable him to cover his operating costs. It is

The large cardamomfarmer uses his bhattionly a few times each

year...hence, he is averseto spending large sums

of money on it


hence common for farmers to retain stocks of dried large cardamom in theirhomes, in order to sell them when the prices are more favourable or to barterthem for other goods and services.

Enter: SDC and TERI

In 1986, TERI submitted a proposal to DST (Department of Science andTechnology), Government of India and got funding to develop an energy-efficient, biomass-fired drier for green cardamom curing in Kerala. Theproject gave TERI valuable field experience in cardamom curing, and showedthe possibilities of using biomass more efficiently in various drying applica-tions.12

In 1993, a bilateral project called ISPS (Indo-Swiss Project Sikkim) was setup between the Government of India (represented by the Sikkim state gov-ernment) and the Swiss government (represented by SDC). ISPS aims atimproving the livelihood of small and marginal farming households in ruralSikkim, through the sustainable and efficient use of natural resources and bypromoting self-governance through empowerment.

Initially, ISPS studied various aspects of Sikkim’s rural economy. Thereaf-ter, it evolved a plan of action to revitalize the state’s cattle and dairy farm-ing sector. In particular, ISPS set up cattle breeding programmes; supportedmeasures to turn around the Sikkim Cooperative Milk Producers’ Union; andestablished a private company, SDPPL (Sikkim Dairy Products Pvt Ltd), toproduce cheese. In addition, ISPS explored the idea of improving the curingsystem of large cardamom by developing and encouraging the adoption oflow-cost technology. However, till 1996, no detailed study had been made ofthe energy performance of traditional bhattis in terms of fuelwood consump-tion, drying temperatures, drying rates, and other parameters.

As mentioned earlier, in 1995 TERI had developed a model oven (Mark 0)to prove the concept of using biomass gasification for cooking silkwormcocoons. In view of TERI’s previous experience in the field of cardamomcuring in Kerala, and its familiarity with gasifier technology, SDC commis-sioned a detailed energy audit by TERI of three selected large cardamombhattis in Sikkim—at Mangan, Naga, and Ravangala. The aim was to gatherdata on the various stages of large cardamom curing, and to examine

12 Mande S, Katam S, and Kishore V V N. 1991. Design, Fabrication, Testing and Field Demonstration ofEnergy Efficient Dryer for Some Cash Crops. [Report submitted to the Department of Science andTechnology, 1991] New Delhi: Tata Energy Research Institute.


whether energy efficiency and product quality could be improved bygasifier-based technology.

Exploring options

TERI’s study revealed that the traditional bhattis had very low energyefficiencies, ranging from 5%–15%. This translated into a huge waste offuelwood, estimated at 20 000 tonnes each year for Sikkim alone. Clearly,there was great scope to improve the energy efficiency of the curing process.However, saving fuelwood meant little in monetary terms to the large carda-mom farmer—because he obtained his fuelwood for free! It was hence un-likely that the farmer would switch from using the traditional bhatti to amore energy-efficient drying technology, unless the latter promised otherbenefits: improvement in the quality of dried capsules, reduction in dryingtime, and so on.

TERI considered three options to increase the efficiency of the curingprocess:� flue gas chamber used by green cardamom farmers in Kerala;� biomass drier developed by TERI; and� biomass gasifier-based drying.

In Kerala, green cardamom farmers use hot flue gases (derived fromburning woody or non-wood biomass) to dry freshly harvested capsules. Thecapsules are arranged in shallow layers on shelves inside a large, insulatedshed or chamber. Hot flue gases are passedthrough pipes over the shelves to dry thecapsules. However, the energy efficiency ofthis system is as low as 3%. Besides, the sys-tem requires the construction of a large cham-ber with an elaborate network of pipes. Suchsystems would be expensive for small andmarginal farmers, and they would also bedifficult to construct and maintain in therugged terrain of Sikkim. TERI thereforerejected this option.

In the course of its DST-funded project in 1986, TERI had designed anddeveloped an improved biomass drier. However, this drier had never beenupscaled from a laboratory-size model. Hence, this option too was rejected.

Saving fuelwood meant littleto the large cardamom

farmer—because he obtainedhis wood for free! Hence, thenew curing technology had

to offer him otherbenefits…such as less curingtime and better quality dried

capsules


That left biomass gasification as an option. A conventional gasifier re-quires a blower or fan, which in turn is driven by electricity. However, mostlarge cardamom farms in Sikkim are located in remote areas without accessto electricity. Hence, the first major challenge before TERI was to design anddevelop a biomass gasifier that operated on natural draft (i.e., without ablower). This was a unique concept in 1996! Besides, the gasifier had to below in cost to make it affordable to the resource-poor farmers.

With SDC’s support, TERI therefore decided to develop a biomass-basedgasifier system for curing large cardamom. As described later, the systemwas designed to meet the following criteria:� increase energy efficiency, and thereby conserve large quantities of

fuelwood;� improve the quality of dried capsules, thereby increasing the earnings of

the farmers;� be easy to fabricate locally;� be easily portable in Sikkim’s remote and hilly terrain; and� be affordable to small and marginal farmers.

INTO THE FIELD

S I LK REEL ING

As described earlier, the project made a detailed study of silk reeling units in1993–94. Based on the study’s results, and as recommended by the ScreeningWorkshop of December 1994, the project decided to develop a gasifier-basedsystem to improve the energy efficiency of cottage basin ovens, which mainlyburn fuelwood. The main reasons were: (1) efficiency of conversion offuelwood to producer gas is high, at about 70%; and (2) use of gaseous fuelwould give higher thermal efficiency and better control over the heatingprocess. Charka ovens were not considered for improvement, because theyburn loose biomass fuels that vary from season to season and according tolocality. It would thus be very difficult to design a gasifier operating on loosebiomass with multi-fuel capability (Box 6).

The project team’s initial plan was simple:� to prove that gasifier technology could be used to provide heat for cocoon

cooking and other purposes such as pupae drying;� to design and develop a suitable gasifier for use with traditional cottage

basin ovens (with inputs from silk reelers to make the process of gasifierdevelopment participatory); and

� to initiate steps to popularize the gasifier.

As the work progressed, however, the project team became aware of theimmense challenges that lay in its path. Developing a biomass gasifier forsmall-scale silk reeling units was an entirely new field. The energy processesinvolved in cocoon cooking/silk reeling were exceedingly complex, requiringintensive analyses and innovative technological solutions. The primary andconstant focus was to increase the energy efficiency of operations (through


Box 6Charka oven—frozen in time

Does the charka reeler have a future?With power looms mass-producingsilk, with Chinese silk flooding Indianmarkets, and with an overall drop inthe prices of raw silk?

In Ramanagaram, Basheer smilesat the question and silently continuesto work at his charka oven. Expertlyhis fingers twirl the silk threads, shift-ing the cocoons around on the bub-bling water in the basin. His10-year-old son Imran turns the well-oiled wooden reel, pausing now andthen to straighten a thread or to undoa knot. Beyond them, in the shadowysmoke-filled interior of the dwelling,Basheer’s wife and daughter work atanother charka. The scene couldhave been taken from centuries ago.

‘There will always be a market forour charka silk,’ Basheer murmurs at

length. ‘The market is not big; our silkmay not earn as much as the finesilks made by the rich reelers whobuy the best cocoons. But whateverwe make, we sell.’ He takes his silk tothe market in Bangalore, twice aweek, where it is bought by traders inCubbonpet.

In the Siddlaghatta silk reelingcluster, Venkatalakshmanan shakeshis head sadly when asked the samequestion. Venkatalakshmanan is 85years old; he operated a charka ovenfor over 60 years. ‘The charkas willslowly disappear; there is no futurefor them,’ he says softly. ‘Yes, thereare always buyers for charka silk. But60 years ago, a family could meet allits needs by operating one or twocharkas. Today it cannot be done…’

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fuel savings and reuse of waste heat). At the same time, the project had tofactor in the importance of making the improved technology acceptable toreelers. A measure or device that promised to improve energy efficiency orproductivity under controlled conditions sometimes turned out to be imprac-tical in field situations, or not to the liking of the reelers because of its sheerunfamiliarity. On the other hand, the reelers sometimes wanted features ormodifications that would lower the gasifier system’s energy efficiency—making it necessary for the project to modify or re-design other parts of thesystem to maintain its performance. Often, an answer found to one problemgave rise to other problems whose solutions demanded fresh research, ex-perimentation, and innovation (see Annexures 3 and 4).

Also, the complexities of the sericulture sector—the economic challengesfaced by silk reeling units, the variations in existing technologies from clus-

Into the field 49

ter to cluster, the diverse threads that bound the fortunes of silk reelers tothose of cocoon farmers, to state policies and market forces—became clearonly as the work progressed. This ongoing learning process highlighted theneed for setting up a mechanism that allowed the project team to meet, sharelessons, and discuss ideas with reelers and other stakeholders—sericultureofficials from state governments, silk experts, manufacturers, and so on. SDCsuggested that regular ‘project coordination-cum-review meetings’ be held toserve this purpose. These meetings were held once every quarter, starting inJuly 1996.

From lab to field: Hindupur yarn

Lab models: Mark 0 and Mark 1-L

As mentioned earlier, TERI put together a gasifier-based model oven,‘Mark 0’, at its research facility in Gual Pahari. Mark 0 had a downdraftgasifier which generated comparatively less tar and particulate matter thanan updraft gasifier, and hence the producer gas was relatively clean. Mark 0was made primarily to demonstrate that gasification technology could beused to cook cocoons (Figure 14). It also included a system to test whether

Figure 14View of Mark 0 prototype atTERI’s Gual Pahari campus


flue gases could be used to dry ‘spent’ cocoons (pupae). The idea was that ifthis system worked, reelers could sell the dried pupae and thereby increasetheir income. Although no experimental data were collected during trial runsof Mark 0, some key observations—positive and negative—were made on theperformance of the gasifier.� By improving the burner’s efficiency, a gasifier-based oven might be able

to achieve an overall thermal efficiency of 35% (compared to 10%–15% fortraditional ovens). This would translate into about 50% savings in fuel.

� In a traditional oven, it was not possible to control the amount of heatsupplied to individual cooking vessels. In Mark 0, individual gas burnersenabled control of heat supply, and the burners could be switched offwhen necessary. This again would help the user to save fuel.

� The pupae drier worked well.� The pipeline that carried gas from the gasifier to the burners got blocked

by deposits of tar and particulate matter, and therefore required frequentcleaning.

� Fuelwood pieces tended to get jammed in the gasifier. Also, the fuel storagecapacity of the hopper was small; hence, frequent fuel-feeding was necessary.

Based on its observations, the project team made a few modifications inthe Mark 0 gasifier and other components to evolve a second improvedlaboratory prototype: Mark 1-lab (or Mark 1-L). Mark 1-L was operated atGual Pahari for eight hours daily (as would be the case in an actual silkreeling unit) for about a month. The idea was to test the system’s reliabilityunder continuous operation, and to pinpoint routine maintenance require-ments. The results showed that there was still scope to improve the perform-ance of the burners. On the positive side, the problem of pipeline blockageobserved in Mark 0 was almost eliminated in Mark 1-L (Box 7).

Field model: Mark 1-F

The next step was to develop and test a field prototype (Mark 1-F) against atraditional cottage basin oven at a suitable silk reeling unit. A site to testMark 1-F was suggested by an official team from the department ofsericulture, Andhra Pradesh headed by the director of APITCO (AndhraPradesh Industrial and Technical Consultancy Organization). The teamvisited Gual Pahari, saw Mark 1-L in operation, and suggested that the fieldversion be tested at Kedar Silk Reeling and Twisting Unit at Hindupur,Andhra Pradesh. Hindupur is a silk cluster mainly comprising charka units;

Into the field 51

Box 7Cooling

chamber

To solve the problem of pipelineblockage by impurities in the fluegas, the project team used a coolingchamber in the Mark 1-L model. Inessence, the cooling chamber com-prised an inverted tank placed in alarger tank filled with water. The hot

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gas from the gasifier was passedthrough the water in the lower tank.This removed most of the tar andparticulate matter from the gas, andthe cleaned gas was led away fromthe upper tank (Figure 15).

Figure 15Gas cooling chamber

only a few units use cottage basin ovens. Hindupur thus provided the idealvenue for a quiet and low-key field-testing of the first-generation field proto-type gasifier system. The purpose was to identify problem areas in Mark 1-F’s design and performance, and to adapt the system to actual field


situations without too many reelers witnessing the tests. Otherwise, reelerswitnessing early tests might pre-judge the technology itself as inefficient orunworthy. Annexure 3 describes the Hindupur experience in greater detail.

Before designing Mark 1-F, the project conducted an energy audit togather baseline data on the performance of the Kedar unit’s existing cottagebasin oven, as this unit had not been covered under TERI’s earlier survey.The audit revealed that the Kedar unit’s existing oven consumed signifi-cantly higher amounts of fuel (2.18 kg fuelwood/kg cocoons) than the typi-cal 6-pan traditional oven (1.70 kg fuelwood/kg cocoons). This appeared tobe due to a combination of low production levels, poor oven design, andpoor operating practices. These factors were taken into account while deter-mining the design and dimensions of the Mark 1-F oven. The project alsotook a number of measures to reduce costs by almost half: from 25 000 rupeesfor Mark 1-L to 13 000 rupees for Mark 1-F.

After finalizing Mark 1-F’s design, two identical gasifiers were fabricatedat a workshop in Delhi. One unit was assembled and operated for a week tocheck and confirm its reliability of performance. Thereafter, the second unitwas packed and sent by road transport to Hindupur in October 1995. Prior toits arrival at Hindupur, a preliminary survey was carried out by the projectteam to identify a fabricator, wood supplier, and mason. At the Kedar unit, aspace was identified for setting up Mark 1-F and necessary structuralchanges (such as the breaking of a boundary wall) were carried out.

Installation, tests and results

Mark 1-F was fabricated and installed at Hindupur in November 1995. Un-like the earlier lab prototype, which was made of steel, the Mark 1-F ovenwas constructed using bricks and ferro-cement slabs and sheets to match theexisting oven’s structure as much as possible. Figure 16 shows the gasifierinstalled at the Kedar unit. Mark 1-F was commissioned in November 1995and was run for a total of 36 days till March 1996. To compare Mark 1-F’sperformance with that of the existing oven at the Kedar unit, cocoons fromthe same lot were processed in batches in both ovens during February–March1996, and data gathered on a total of 13 comparative tests.

The results were largely encouraging. On an average, the Mark 1-F ovenreduced fuel consumption by nearly 50%. Also, a chance observation indi-cated that the field prototype improved the yield of silk by a small but sig-nificant amount—a very big thing for the Indian silk industry (Box 8)!

In order to assess and compare the quality of silk yarn produced by Mark1-F and the existing oven, samples of yarn produced by both ovens were sent

Into the field 53

Figure 16Gasifier system installed at Hindupur:

(a) gasifier; (b) cooking oven with pupae dryer

(a)

(b)


to the CSB laboratory at Dharmavaram for analysis. The results showed thatthe Mark 1-F yarn was superior in quality.

In the light of these developments, the project realized that it was essen-tial to evaluate the quantity as well as the quality of raw silk producedduring various stages of development of the gasifier-based reeling system.This required in-depth knowledge of silk technology—specifically, expertisein assessing parameters of raw silk yarn such as denier, tenacity, elongation,cohesion, and so on. T S Nagaraja, a textile technologist with considerableexperience in the silk industry, wasidentified to help the project inassessing the qualitative and quanti-tative improvements of the silk yarnproduced in the course of systemdevelopment.

Box 8Improved silk yield:icing on the cake!

In silk reeling, productivity is meas-ured in terms of ‘renditta’—the weightof cocoons needed to produce onekilogram of raw silk. The lower therenditta, the better the silk yield.While the traditional oven showed anaverage renditta of 7·72 (that is, it re-quired 7·72 kg cocoons to produce 1kg raw silk), the Mark 1-F prototypeshowed an average renditta of 7·62.In effect, Mark 1-F yielded an averageof over 170 g more silk than the tradi-tional oven for every 100 kg of co-coons processed. This was indeed avery exciting discovery! Calculationsshowed that the gains from obtaininglow renditta could far outweigh thegains from improving fuel efficiency.This raised huge expectations of thegasifier system.

During the trial runs, the projectteam observed that besides improv-ing productivity in terms of the quan-tity of silk produced (lower renditta),Mark 1-F also seemed to enhanceworker’s productivity in terms ofspeed. This was probably becausethe gasifier system was able to pro-vide water at more uniform and con-sistently high temperatures forcooking than the existing oven. Work-ers did not have to wait as long forthe water in the cooking vessels toboil, nor did they have to changefuelwood feeding rates to maintain orincrease the heat supply to the ves-sels. Overall, this allowed workers toprocess more cocoons each day.

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Calculations showed that the gainsfrom obtaining better silk yield

could far outweigh the gains fromimproving fuel efficiency

Into the field 55

First design review workshop

Having successfully tested the Mark 1-F prototype, the next step was to tryand improve its design, in order to make it readily acceptable to entrepre-neurs and workers. Reelers were therefore invited to Hindupur to witness ademonstration of the prototype. The reelers came from Ramanagaram,Kanakapura, and Chennapatna clusters in Karnataka. These are among thelargest silk reeling clusters in the country, and have a very large number ofcottage basin units. Thereafter, on 2–3March 1996, the project organized a‘design review workshop’ atBangalore. Among the participantswere reelers, design experts, and silktechnologists. The main objectives ofthe workshop were to obtain thereelers’ feedback on Mark 1-F’s per-formance; to ascertain the specificrequirements of reelers from the Ramanagaram cluster (where extended fieldtesting of the gasifier oven was planned); and to review the design of thegasifier oven and get suggestions from experts on how it could be modifiedto yield better performance, reduce costs, and make it user-friendly.

The reelers provided valuable feedback on the gasifier oven, which helpedthe project in designing a second field prototype—the Mark 2 gasifier oven—for field-testing in Ramanagaram. Surprisingly, the reelers did not want thepupae drier despite its good performance, as they were reluctant to handlepupae. This provided an important lesson for the project team: in order tosucceed, improved technology must be compatible with community traditionand culture. What was originally thought of as an additional income genera-tion option for reelers was culturally not acceptable to them.

The project outlined the economic benefits to be had by using theMark 1-F gasifier-based oven. The gasifier alone (with its sub-componentssuch as blower, cooling chamber, etc.) cost 12800 rupees, and the oven’soverall cost came to around 50 000 rupees. This was substantially higher thanthat the cost of the conventional cottage basin oven (9000 rupees). However,the gasifier oven yielded a daily savings of 271 rupees (73 rupees on accountof fuel savings and 198 rupees due to renditta improvement). Thus, thepayback period worked out to 185 days or a mere six months.

Interactions at the workshop reinforced the project team’s conviction thatto make the gasifier-based system attractive to users, reelers’ feedback and

The reelers did not want the pupaedrier, despite its good performance! Itwas an important lesson...in order tosucceed, improved technology must

be compatible with communitytradition and culture


involvement of design experts would be essential at every stage of its devel-opment. Hence, regular ‘project coordination-cum-review meetings’ wereheld once every quarter to facilitate interactions and exchange of ideas withreelers and other stakeholders. The project identified Prof. Vijay Bapat of theIndustrial Design Centre, IIT, Mumbai, to provide the necessary expertise inproduct design. Prof. Bapat’s inputs proved vital during the development ofthe system. At each stage, he suggested changes in design that improved thesystem’s appearance and added operator-friendly features.

Ramanagaram yarn: participatory approach

Based on the reelers’ suggestions at the first design review workshop, theproject proceeded to make a second field prototype—Mark 2. It was decidedto conduct field trials of the Mark 2 gasifier-based oven at selected sites inRamanagaram—Asia’s largest silk reeling cluster, located about 50 km fromBangalore. The project also decided to continue long-duration tests of theMark 1-F oven at Hindupur. Mark 1-F was run for a total of 90 days tillAugust 1996, when the Kedar unit shut down due to a shortage of cocoonsand consequent financial problems.

Two reelers from Ramanagaram—Sukhindra Rao Babu and Mohib Pa-sha—offered their units in which to conduct field tests and demonstration ofMark 2. ‘Both Pasha and Babu had witnessed the trials of the Mark 1-Fprototype in Hindupur, and provided valuable feedback that helped indeveloping and designing the Mark 2 oven,’ recalls silk expert T S Nagaraja.‘Both showed an open-mindedness to change, an enthusiasm to try out newtechnology. They were willing to experiment; to take calculated risks. Thesefactors weighed in their favour when selecting sites for field-testing Mark 2.’

Mark 2: design, fabrication, and installation

The first step was to gather baseline data on Pasha’s and Babu’s units. InApril 1996, the project team visited the Ramanagaram cluster and monitoredand gathered data on the two units’ operations. The data enabled the projectto determine Mark 2’s design details (see Annexure 4). In designing Mark 2,a number of changes had to be made in the design of Mark 1-F and its sub-components. At the same time, the focus was on reducing costs whereverpossible.

After finalizing the Mark 2 system’s design, detailed engineering draw-ings were prepared and one system was fabricated, installed, and tested at

Into the field 57

Gual Pahari in May 1996. The system met the desired performance param-eters. Thereafter, a Bangalore-based fabricator (Jaykay Industries) was pro-vided with the engineering drawings and asked to manufacture two gasifiersaccording to specifications. Accessories and components such as the burnersets, blower assemblies, sections of pipeline, and so on were procured inDelhi and transported to the Ramanagaram sites. Two sets of cooking ves-sels—each comprising six copper basins—and stainless steel heat recoverydrums were bought from CSTRI, Bangalore. Masonry work was done withthe help of a local mason under TERI’s supervision. In May–June 1996, thetwo Mark 2 systems were fabricated and installed, one each in Pasha’s andBabu’s units, and trial runs commenced (Figure 17).

Trial runs and results

It proved an immense struggle for the project team to conduct the trial runsof Mark 2. While the gasifier system performed according to expectations atBabu’s unit, the operations at Pasha’s unit were far from smooth. From theoutset Pasha complained that Mark 2 was not performing well; specifically,that it was not able to supply his reelers with cooked cocoons at a fastenough rate. The project team soon realized that this was not due to anytechnical fault in Mark 2. Rather, it was because Pasha had suddenly anddeliberately increased his rate of production of raw silk yarn (Box 9). Pashawas making his reelers work much faster than normal; naturally, the reelerswere demanding cooked cocoons more quickly from both the existing ovenand Mark 2.

The project team conducted a fresh study of Pasha’s existing oven. Theresults confirmed that Pasha had indeed driven up his rate of production.With the existing oven, increasing the cocoon processing rate posed noproblem; it was simply a matter of feeding and burning wood logs at a fasterrate in its hearth, because energy efficiency did not matter. However, theMark 2 system was designed to maximize fuel savings. Any attempt todeviate from the set parameters (such as increasing fuelwood burning rates)would lower the system’s energy efficiency and negate the very purpose forwhich the system had been developed.

The project tried its best to meet Pasha’s persistent demand for higheruseful power from Mark 2 without decreasing its energy efficiency. Newburners were procured, tested and installed in the oven; the blower wasreplaced; a higher-capacity gasifier—sufficient to meet Pasha’s increaseddemands—was designed, fabricated, and tested at Gual Pahari, and Pasha’sMark 2 gasifier re-modelled accordingly.


Figure 17Mark 2 system at Pasha’s unit, Ramanagaram:

(a) schematic; (b) view of system

(a)

(b)

Into the field 59

However, the problems did not cease with these changes. With Pashacontinuing to complain about the Mark 2 system’s ‘under-performance’, theproject team dismantled the entire gasifier oven for critical examination.Tests were also conducted on the quality of wood being burned in Mark 2during the trial runs. The following facts emerged.� The gasifier’s insulation lining had cracked, and the material itself did not

match that specified in design documents. The result: lower thermalefficiency.

� The copper cooking vessels bought from CSTRI were larger (8 litres) thanthe 7-litre vessels usually used in conventional ovens. Thus, the vessels inMark 2 held more water and therefore took up more heat than those in theexisting ovens. This was the case in both Pasha’s and Babu’s units.

� The fuelwood that was being burned in Pasha’s Mark 2 was of poor qual-ity, with high moisture content (up to 15%) and low calorific value.

Box 9Power struggle at

Pasha’s unit

The initial baseline data gathered inApril 1996 showed that Pasha proc-essed around 90 kg cocoons daily inhis existing conventional oven—whichwas the average among reeling unitsacross the industry. The Mark 2gasifier system was designed to meetthis rate of cocoon processing. How-ever, as soon as Mark 2 was commis-sioned at Pasha’s unit, theentrepreneur proceeded to increasehis rate of production till by mid-June1996, he was processing around 135kg cocoons daily! In effect, he had in-creased his processing rate by al-most 50%. At the same time, hecomplained that Mark 2 was not per-forming satisfactorily because it wasnot supplying cooked cocoons at therate required by the reelers.

It soon became apparent that Pashawas pushing his reelers extra hardonly because he wanted to reap themaximum benefits from the newgasifier system while it operated inhis unit. Indeed, the project madeevery effort to meet Pasha’s de-mands for increased ‘useful power’from Mark 2. Four of the existingburners were replaced by larger burn-ers; the gasifier itself was redesignedwith enlarged capacity and a largerfuelwood hopper; and a new high-speed blower was installed at theproject’s own expense. Finally, inSeptember 1996 Pasha expressedsatisfaction with the modified Mark 2system at his unit—to the extent thathe wanted the system’s power levelto be reduced slightly!

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In both Pasha’s and Babu’s units, the gasifier lining material was changedand the existing cooking vessels replaced by 7-litre vessels. Steps were alsotaken to reduce the smoke emitted by the gasifier ovens. From September1996 to March 1997, regular comparative tests were conducted of the Mark 2systems against the existing ovens. The results were indeed encouraging.Mark 2 brought about a fuel saving of 46%. Also, it enabled production of anextra 310–370 g of silk on an average from every 100 kg of cocoons proc-essed. Samples of the raw silk produced by both Mark 2 and existing ovenswere sent to a laboratory at Bangalore for analysis to compare their quality.The tests revealed that the Mark 2 silk yarn was significantly superior inquality to that produced in the existing ovens.

Planning the next stages

Technically, Mark 2 had performed well. Yet much work was still needed tomake an ‘industrial’ model of the gasifier-based oven—a model that resolvedtechnical problems existing in Mark 2 while retaining its energy efficiency,and that could be manufactured on an industrial or ‘mass production’ scalewith standardized components.

Also, considering the micro-level nature of the silk reeling industry andthe extremely lean profit margins on which units operated, the project real-ized that reelers might find it difficult to make large up-front investments onthe gasifier-based system. It was important to evolve a marketing plan, onethat sought and found ways by which reelers could obtain financial assist-ance to acquire the gasifier system.

Thus, with successful demonstration of Mark 2 and its potential to im-prove energy efficiency and product quality, the time had come to study thepotential market for the system as well as to examine issues related to itsmanufacture. Also, earlier visits to silk dyeing units in Hindupur had madethe project aware of the possibility of using gasifier-based technology tomeet the thermal needs of small-scale fabric dyeing units. To explore thisidea further it was necessary to get a clearer picture of the industry: the sizeand spread of dyeing units, their energy needs and fuel consumption pat-terns, the nature of their processes and existing ovens, and so on. The projecthence initiated three studies:� a cluster study of silk reeling units in Ramanagaram by TS Nagaraja;� a study by I J Raju and Associates, Delhi, of issues related to the manufac-

ture and marketing of gasifier-based reeling ovens; and� a field survey of silk and cotton dyeing units in south India by BIET

(Bapuji Institute of Engineering and Technology), Davangere.

Into the field 61

The results of all three studies were presented at the second design reviewworkshop held in Delhi in March 1997, as described later.

Mark 3: the first quantum leap

To initiate efforts to develop an industrial prototype—Mark 3—two consult-ants were engaged by the project. The first was Prof. Vijay Bapat of IITMumbai; he had earlier visited Hindupur and studied Mark 1-F in operation,and also participated in the first design review workshop held in Bangalorethereafter. The second was Kvaerner Powergas, a reputed engineering anddesign firm based in Mumbai.

Prof. Bapat visited Ramanagaram in January 1997 to study the Mark 2system in detail. A team from Kvaerner Powergas too visited the sites inFebruary 1997. Both consultants made anumber of suggestions that provedinvaluable in re-engineering the com-plete gasifier system to make it morecompact and its many componentssuitable for large-scale production. Themeasures they suggested included the following:� setting exact standards for each component in terms of parameters such as

material composition, temperature, pressure, flow, and so on to ensuregood quality control and to enable easy manufacture;

� standardization of dimensions to enable easy assembly of parts and better,faster after-sales service;

� stackable components to make them easy to pack and transport;� removable parts (such as burners) to enable easy cleaning/maintenance;� reducing bends and joints in pipes and tubes to enable easier cleaning;

and� user-friendly features.

The project team also met several manufacturers, fabricators, and consult-ants at Mumbai, Delhi, Coimbatore, and Bangalore to gather ideas on how toimprove Mark 2’s design. Some among them had witnessed Mark 1-F inaction at Hindupur and had participated in the first design reviewworkshop. Many interesting ideas emerged from the interactions (seeAnnexure 4).

In Mark 1-F as well as Mark 2, the water in the heat recovery drum didnot reach temperatures above 60 °C. Hence, steps were taken to improve heat

The Mark 3 had a single commonwater bath instead of separate

basins…it represented a quantumleap in technology development


recovery in Mark 3. Another major problem with the Mark 2 system was itssheer size, which made it inconvenient to install and operate in the crampedenvironment of small-scale reeling units. Based on observations made duringfield-tests, the project team realized that instead of having six separate basinsit was possible to use a single common water bath divided into severalcooking vessels. Using a single water bath meant that a single burner couldbe used instead of six burners. All these radical changes, undertaken simulta-neously, made the Mark 3 system’s design much simpler and trimmed downits size. Mark 3 thus represented a quantum jump in development of thetechnology.

The first industrial prototype of the gasifier-based oven—Mark 3—wasdesigned with the above features, and its fabrication was entrusted to UrjexBoilers Pvt. Ltd, a firm based in Meerut (Uttar Pradesh). In March 1997, theMark 3 system was fabricated and installed at TERI’s campus in Gual Paharifor tests (Figure 18).

Figure 18Industrial prototype Mark 3fabricated by Urjex Boilers

Into the field 63

Second design review workshop

The same month, a second design reviewworkshop was held—this time in Delhi(Box 10). Several silk reelers attended theworkshop. They were also taken to GualPahari, where they tried out Mark 3 usinga small amount of cocoons brought fromBangalore. The reelers’ responses were very positive. In particular, they likedthe simplicity and compactness of Mark 3’s design, for it would occupy

Box 10A landmark

event

The second design review workshopwas held at Delhi in March 1997 andattended by silk reelers; gasifiermanufacturers; representatives fromsilk research institutions; officialsfrom various state departments ofsericulture; silk experts and consult-ants; and, of course, project staff. Itwas perhaps the first ever occasionwhen people from such a wide spec-trum of activities related tosericulture interacted on a commonplatform and shared their views andideas (Figure 19).

Project members described howthe Mark 2 gasifier-based reeling sys-tem had been developed in stages,based on field trials at Hindupur andRamanagaram. They highlighted thefact that Mark 2 yielded fuelwoodsavings of nearly 50%, which trans-lated into a daily saving of about 100rupees on fuelwood costs. Also, Mark2 increased silk yield by about 300 g

for every 100 kg of processed co-coons, which meant an additionaldaily profit of about 300–350 rupeesfor the reeler.

The project had earlier commis-sioned three studies: (1) a cluster-level study of silk reeling units inRamanagaram, conducted by T SNagaraja; (2) a field survey of fabricdyeing units (silk and cotton) insouthern India, conducted by BIET(Bapuji Institute of Engineering andTechnology), Davangere; and (3) astudy of issues related to manufac-ture and marketing of gasifier-basedsystems, conducted by I J Raju andAssociates, Delhi. The results ofthese studies were presented anddiscussed at the workshop.� The cluster study of Ramanagaram

by T S Nagaraja highlighted thenarrow profit margins within whichthe average silk reeling unit oper-ated. With its ability to cut down

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Continued

The March 1997 design reviewworkshop was perhaps the first

time ever that people from acrossthe sericulture field met on a

common platform to share viewsand ideas


Box 10 (Continued)

fuelwood costs by nearly half, thegasifier-based oven offered greatpotential to improve the profitabil-ity of silk reeling units. Nagaraja’sstudy suggested that of the esti-mated 578 cottage basin units inRamanagaram, around 60% mightbenefit by adopting the gasifier-based oven.

� The study by I J Raju and Associ-ates emphasized the fact that silkreelers obtained their existing ma-chinery (including the traditionalcottage basin ovens) at subsidizedprices. This made it vitally impor-tant for the project to select theright manufacturer(s) and market-ers for its gasifier-based oven. Is-sues such as pricing, qualitycontrol, and patenting of thegasifier system’s design (to pre-vent copying) would be crucial to

ensure its successful commerciali-zation. The study suggested anumber of criteria upon which toevaluate potential manufacturing/marketing firms—turnover, cus-tomer base, financial soundness,experience, technical resources,after-sales network, and so on.

� BIET had surveyed a total of 36fabric dyeing units in Karnataka,Tamil Nadu and Andhra Pradesh.About 80% of these units usedfuelwood to meet most of their en-ergy requirements. They also useddiesel and kerosene as supple-mentary fuels. The survey sug-gested that most units would bewilling to try out a gasifier-baseddyeing system, provided that it re-duced their fuel costs by 30%–50%.

The design review workshop wasindeed a landmark event for theproject. It provided vital insights intothe many facets of the sericulture in-dustry, valuable feedback fromreelers and others on Mark 2 as wellas on the Mark 3 model in GualPahari, and suggestions on how Mark3’s design could still further be im-proved upon. The workshop pavedthe way for the project’s later work infine-tuning the gasifier-based reelingsystem, and in finding manufacturersand marketers for the system. It alsolaid the foundations for developinggasifier-based systems for silk dyeingunits.

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Figure 19Second design review workshop

at Delhi, March 1997

Into the field 65

much less space and make maintenance much easier. They also suggested afew more modifications in the system’s design which were duly carried out.

Mark 3: fabrication, trials, and results

From its earlier experiences with the Mark 2 trials, the project team realizedthat Mohib Pasha was a far more demanding and influential reeler thanSukhindra Rao Babu. Indeed, on many occasions Babu had expressed satis-faction with the Mark 2 system at his unit, but changed his mind and echoedPasha when the latter had expressed dissatisfaction over some feature! Theteam therefore decided to try out the Mark 3 system first at Pasha’s unitalone, and to fabricate and commission a second system at Babu’s unit onlyafter ironing out any problems that Pasha might identify.

In September 1997, an improved Mark 3 system was fabricated by UrjexBoilers and installed in Pasha’s unit for trial runs. The system operatedwithout difficulties, and so in January 1998 a second system (again fabricatedby Urjex Boilers) was installed in Babu’s unit. Trials on both systems wereconducted till September 1998. Both systems performed exceedingly well, assummarized below.� Mark 3 reduced wood consumption by over 60%.� Mark 3 produced 370–390 g more silk than the existing cottage basin oven

for every 100 kg of cocoons processed.� Tests established that the quality of silk produced by Mark 3 was superior

to that produced by existing ovens in both Pasha’s and Babu’s units.� On an average, the cocoon processing rate of the Mark 3 systems was

11%–12% faster than that of the traditional ovens. In effect, an extra 1.05kg/hour of cocoons could be cooked using the Mark 3 system. Also, Mark3 reduced water consumption by an average of 860 litres for every 100 kgcocoons processed.

� Mark 3 generated much less smoke and other emissions than traditionalovens.

Mark 4: the second quantum leap

With the successful development and test-ing of the Mark 3 system, the technologyhad ‘matured’. The time had come to designa marketable model that yielded all thebenefits of Mark 3, but was more user-

The Mark 4 was made of stain-less steel, and its components

designed in modular fashion...itthus represented a second

quantum leap in technologydevelopment


friendly and attractive as a product. Thus, Mark4—the first commercial version of the gasifier-based silk reeling system—was born.

The Mark 4 system retained all the techno-logical benefits of Mark 3, but its design wasmodified to incorporate many user-friendly features based on suggestions byProf. Bapat of IIT, Mumbai. The gasifiers in all the earlier models were madeof mild steel. Mark 4’s gasifier was designed to be made of stainless steel.Furthermore, to make it easy to transport, assemble, and commission, theMark 4 system’s components were designed in such a way that they could bemanufactured on a large scale in modular fashion. Notably, Prof. Bapat usedcomputer simulations and scaled-down plastic models to study the human–machine interface and develop a user-friendly product (Figure 20). Mark 4thus represented a second quantum jump in development of the gasifier-basedsilk reeling system (Box 11). With its development, the stage had come for theproject to find firms capable of manufacturing the system.

Figure 20View of a scaled-down model to study human–

machine interface while evolving Mark 4

“The development of atechnology that takes into

account users’ needs requiresa number of iterations …”

Into the field 67

Box 11Participatory technology

development: no short-cuts

It took about five years to go from thefirst ‘proof-of-concept’ lab prototypeof the gasifier-based reeling systemto the commercial model. If I hadbeen asked at the beginning of theproject, ‘How long will it take to de-velop a simple thermal gasifier?’ Iwould have answered: ‘Let’s say,maximum one year.’

This experience shows that evenwith hard work, the development of atechnology, which takes into account

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the user’s needs, requires a numberof iterations and successive phasesof development. It is an illusion to be-lieve that one can jump across allthese stages of development. If wehad gone much faster, some of thesolutions we developed just wouldnot have come up (Figure 21).

Pierre JaboyedoffSorane SA

Figure 21Stages in technology development


Finding the right manufacturers

It was indeed a challenging task to find manufacturers who could make thegasifier-based reeling system, and firms that could successfully sell thesystem to reelers. Over the decades, government departments and agencieshad almost exclusively procured and supplied machinery and equipment tothe sericulture industry, including silk reeling units. There was little or nodirect contact between manufacturers and reelers. No formal systems existedto obtain or document feedback from reelers on the performance of theequipment supplied to them. In the absence of such data, the project had toevolve its own mechanism to find the right firms to manufacture and marketthe gasifier-based reeling system. To provide advice on this, the projectidentified two consultants: Pierre Jaboyedoff of Sorane SA, Switzerland andGreg Wishart of Ashton Court Consultants Ltd, UK. The project also set up asmall internal team to examine various marketing ideas and models.

As a first step, the project’s internal team conducted a preliminary reviewof potential manufacturers and marketers for the gasifier system, and short-listed a number of firms. A detailed questionnaire was prepared and sent tothese firms. After studying the responses, the project identified a marketingfirm—Greenergy Systems—who appeared to be both capable and willing tomarket the gasifier systems. The project also visited a few firms at Bangalore,Coimbatore, Delhi, and Yamunanagar to interview their owners and studytheir plants. Finally, based on its preliminary survey, the project team pre-pared the first draft of a basic framework to manufacture and market thegasifier system. This draft was given to the consultants for appraisal, alongwith a draft license agreement between TERI and the potentialmanufacturer(s).

In November 1998, the consultants visited the sites of the following manu-facturing/marketing firms and held discussions with their owners andrepresentatives:� Urjex Boilers Pvt. Ltd, Meerut;� Silk Tex/Aryan Industries, Kanakapura;� Greenergy Systems, Bangalore;� Vijay Engineering Enterprises, Bangalore; and� 2M Industries, Mumbai.

Based on their interactions, the consultants made the following observations.� The gasifier-based system comprised a number of component parts that

required a range of fabrication skills and different kinds of equipment.

Into the field 69

� While the short listed firms possessed the required fabrication skills tovarying degrees, no single firm possessed the gamut of skills needed tofully make a commercial model of the gasifier system. For instance, a firmthat was capable of producing the mild steel parts of the gasifier did nothave either the skills or the equipment to fabricate the stainless steelcomponents of the system.

� The studied firms were accustomed to fabricating products based on thedrawings that they had obtained from their clients or from third parties.This implied that the project would have to exercise very tight controlover the design and specifications of the gasifier system.

� Working with different manufacturers in the absence of tight specifica-tions, as well as allowing a single manufacturer to make complete sys-tems, could lead to quality control problems and relatively high prices.Replication of the gasifier system without quality control would be disas-trous.

A strategy is evolved

Based on their observations, the consultants made the following recommen-dations (Figure 22).� The gasifier system should be designed in such a way that its various

components could be assembled easily.� The project should build a package of detailed technical specifications and

production engineering drawings for the gasifier system’s many components.� The project should refrain from handing over the responsibility for the

design and manufacture of the entire system to a single firm during theinitial phase. This was because the risks of drop-out, poor quality control,and higher costs were maximal with a single fabricator/manufacturer.

� Manufacturers/workshops to make the components should be selectedbased on their ability to supply the components within the agreed budgetand delivery time-scales. Tight quality control would have to be main-tained at every stage of manufacture.

� The selected marketing agency would use the technical specifications andproduction engineering drawings/documents to purchase specifiedcomponents from chosen manufacturers/workshops. It would also be incharge of installing and commissioning the gasifier-based systems.

� The marketing agency should source the components as follows:• gasifier and burner from a fabricator of MS (mild steel) products;• cocoon cooking unit and heat recovery drum from a fabricator of

stainless steel products; and


• ancillary components from the market, strictly according to their tech-nical specifications.

� TERI would have to train the staff of the marketing agency in installationand commissioning of the gasifier systems.

Manufacturers are chosen

Based on the consultants’ recommendations, TERI approached a number oforganizations to help prepare the Mark 4 system’s technical specificationsand production engineering documents. However, TERI found that theseorganizations dealt with well-established commercial technologies, and theirclientele mainly belonged to the large-scale organized sector. None of themhad any experience with the small-scale silk reeling sector. Under the circum-

Figure 22Basic framework for

commercialization of technology

Into the field 71

stances, TERI prepared the required documents on its own. The documentscontained detailed descriptions of each part/component of the Mark 4gasifier system, the materials used to make it, the fabrication processes, andthe quality requirements. The documents also included engineering draw-ings of various components and of the assembled Mark 4 system.

Thereafter, the project approached various manufacturers in order todiscuss the Mark 4 design specifications and to obtain quotations for manu-facture of the systems’ various components. The quotes received ranged from45 000 rupees to 110 000 rupees for the entire system, with the averagequoted price being around 72 000 rupees. With expected savings of 750rupees per day, this meant that the Mark 4 system promised to pay backinvestors’ money in a mere three to four months.

Based on the quotations received, three firms were short-listed by theproject and asked to fabricate gasifier ovens for field-testing. They were:� Urjex Boilers Pvt. Ltd, Meerut;� 2M Industries, Mumbai; and� Silk Tex Industries, Kanakapura.

In each firm’s case, the project agreed to reimburse the costs of making thefirst system. The idea was to sell these systems to reelers (under flexibleschemes of payment) after the reelers were satisfied with the systems’ per-formance.

Into marketing: test flights

Urjex Boilers—hard landing

The first Mark 4 system was ordered from Urjex Boilers Pvt. Ltd, Meerutthrough Greenergy Systems by a silk reeling unit in the Chennapatna cluster(S R Textiles). The system was inspected for quality by the project teamduring fabrication, tested at TERI’s research facility at Gual Pahari, and theninstalled and commissioned by the project team in April 1999. Its perform-ance was monitored during April–May 1999. The results indicated averagefuel savings of over 58% and an increase in production of silk.

Urjex Boilers did not have a marketing set-up in south India. The firmdecided to tie up with Greenergy Systems—the marketing agency alreadyidentified by the project—to promote its gasifier system. However, the twofirms faced difficulties in entering into a mutually satisfactory financialarrangement for marketing. Neither was in a position to place cash up-frontfor the gasifier systems. Urjex Boilers was a small firm; it could not afford to


make and supply the systems on credit. On the other hand, Greenergy Sys-tems was not in a position to obtain advance payments from the buyers, nordid it have the capacity to make down-payment for the systems on its own.These difficulties, coupled with other factors such as geographic distancefrom Bangalore and lack of presence in the south, finally led Urjex Boilers todrop out of the race.

Silk Tex—smooth but short flight

In December 1999, the project asked Silk Tex to make a Mark 4 system forfield-testing. This firm is a sister concern of Aryan Industries, Kanakapura—one of the oldest and most reputed manufacturers of silk reeling equipment.To assist in manufacturing the gasifier systems, Silk Tex entered into anarrangement with a Bangalore-based sheet metal fabrication unit.

Silk Tex fabricated its first Mark 4 system under the technical guidance ofthe TERI team. After testing, the system was taken to the Kanakapura clus-ter—which has over 500 cottage basin units—and was installed atKrishnappa’s unit in September 2000. The system performed well, to thesatisfaction of the entrepreneur. However, the entrepreneur found it difficultto obtain a regular supply of dry fuelwood cut into appropriate size. Silk Texdemonstrated its system at an exhibition in Kanakapura from 9–12 Novem-ber 2000. Thereafter, the firm decided to concentrate on its established busi-ness of supplying state-subsidized reeling equipment such as the ‘multi-endmachine’ to CSTRI.

2M Industries—successful launch

In May 1999, 2M Industries fabricated its first version of the Mark 4 systemunder the supervision of the project team. Prof. Vijay Bapat provided valu-able advice to make the design user-friendlier. The proprietor of the firm,Mohan Kulkarni, showed considerable skill and creativity in making thesystem in modules that were easy to transport and assemble as well as pleas-ing in appearance. After successful tests at the plant itself, the system wasshifted to the Ramanagaram cluster for field tests (Figure 23).

Because it did not have a marketing base in Karnataka, 2M Industries toodecided to tie up with Greenergy Systems for marketing its system. How-ever, differences arose between the two firms over sharing of the marketingcosts. Thereafter, 2M Industries decided that it would market the system onits own. 2M Industries set up its own marketing and sales teams, andlaunched a test-marketing and demonstration programme for its gasifier-based reeling system (Box 12).

Into the field 73

Based on their experiences during the field-tests and demonstrations, theproject team and 2M Industries realized that in order to successfully marketthe gasifier oven, it was vital to make reelers aware of the great benefits thenew gasifier-based system offered, in terms of fuel-savings, profits, andproductivity. At 65000 rupees, the cost of the system was high compared totraditional cottage basin ovens; hence, it was decided that the system shouldinitially be targeted only at the more affluent reelers.

To reduce the costs of market promotion, 2M Industries decided to takeadvantage of the economics of scale. It set about fabricating eight systems,for which SERI 200013 agreed to provide 50% of working capital support. In

Figure 23Commercial model developed

by 2M Industries

13 SERI 2000 was an innovative programme established by SDC and the Ministry of Textiles,Government of India to implement projects in sericulture from 1997–2002. With an outlay of 12.5million Swiss francs, SERI 2000 aimed at creating and supporting viable enterprises in thesericulture sector to generate employment and sustainable sources of income, especially amongweaker sections of the populace. The programme covered projects in both public and private sectorsin Karnataka, Andhra Pradesh, Tamil Nadu, and West Bengal.


Box 12Road show for

Mark 4

In August 1999, 2M Industries alongwith the project team started market-ing the gasifier-based silk reelingoven in the Ramanagaram,Kanakapura, and Chennapatna silkreeling clusters. To generate aware-ness among the reelers about thegasifier system and its benefits, theoven was assembled on a tractor trol-ley and taken to the Ramanagaramcocoon market for a ‘road show’. Ban-ners were displayed in local lan-guages about the gasifier system,which was operated on the trolley. Of-ficials from the sericulture depart-ment and about 400–500 reelerssaw the system in actual operation.Some of the reelers also tried actualcooking of cocoons in the system.Brochures containing informationabout the system and its benefitswere distributed to the reelers. Theirinitial response was very enthusiasticand highly encouraging. It was prob-ably the first public demonstration ofa device developed by the privatesector for the silk reeling sector.

Most reelers wanted to know un-der which ‘scheme’ the system wasbeing promoted. Upon being in-formed that the gasifier oven was notbeing promoted under any statescheme, and that subsidy would notbe available, their reactions weresomewhat mixed. While some ofthem forcefully argued that weshould approach the government tolaunch a ‘scheme’ for the oven, oth-ers felt that it should be demon-strated in actual reeling units insome dense clusters for some time.

A few reelers wanted to acquirethe system, but requested a soft-pay-ment option involving monthly instal-ments. Reelers from other clustersalso came and saw the system. BothPasha and Babu, with whom we hadbeen closely associated during field-testing, endorsed the benefits of thegasifier oven and played a very positiverole in disseminating information.

Sunil DhingraTERI

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January 2000, TERI tested the completed systems. They were then trans-ported to Ramanagaram. After extensive marketing efforts, two systems weresold in Chennapatna and one in Kanakapura. To overcome the reluctance ofclient reelers to make a large financial commitment at one go, in each case2M Industries made the ovens available against an advance payment of20%–25% and a monthly instalment of 5000 rupees. In May–June 2000, fourmore systems were sold to and installed at government silk reeling units inTamil Nadu.

Into the field 75

Also in early 2000, TERI formally transferred the technology for manufac-ture and marketing of the integrated gasifier-based silk reeling system to 2MIndustries and Silk Tex. Both firms had refined the gasifier-based system interms of design and user-friendliness; their ovens performed well; they weremade from durable, long-lasting materials; and they were attractively de-signed. In short, they were eminently marketable.

To increase awareness in the silk industry about the new gasifier-basedreeling systems, the project team made intense efforts to market them in thesilk reeling clusters in Karnataka as well as in Tamil Nadu and AndhraPradesh (Box 13).

Demonstrations were carried out for the system at the venues listed below.� August 2000 ‘AGRI INTEX 2000, Coimbatore. This was an exhibition on

agriculture-related technology held at the Coimbatore District SmallIndustries Association Trade Fair Complex.

� August 2000 Silk Training Centre, Coimbatore. This exhibition wasorganized by DoS, Tamil Nadu.

� October 2000 IREP (Mahatma Gandhi Institute of Rural Development,Jakkur, Bangalore). Over the years, TERI (Bangalore) had been conductingtraining programmes for IREP staff in the areas of energy and the environ-ment. This demonstration was of particular significance, as IREP person-nel worked at the grassroots level and were in constant and close touchwith silk reelers.

� November 2000 ‘Rural Enterprises Summit’, Mysore. This summit wasorganized by CII (Confederation of Indian Industries).

� November 2000 during the inauguration of DoS Karnataka’s new build-ing, Reshma Bhavan, in Bangalore on 23 November 2000. Besides theChief Minister of Karnataka, representatives of the Sericulture ResearchDevelopment Institute, CSB, Karnataka Silk Marketing Board, and reelersand weavers from all over the state were present at this function.

� One unit was also placed for display and demonstration at TERI’spremises in Bangalore. This was shown to several people, includinggovernment officers, entrepreneurs, etc.

Efforts to garner support of financial institutions

On 10 February 2000, a meeting was organized by the project with repre-sentatives from SIDBI (Small Industries Development Bank of India),NABARD (National Bank for Agriculture and Rural Development), CanaraBank, Syndicate Bank, KSFC (Karnataka State Financial Corporation), CSB,and DoS, Karnataka. The idea was to examine whether the gasifier-based


Box 13‘SERI 2000 oven’—involving

the public sector

SDC decided to involve the publicsector in facilitating the marketing ofthe Mark 4 gasifier system. A demon-stration-cum-launching workshopwas organized on 30 October 1999at the Chennapatna Sericulture Train-ing Centre. Participants at the work-shop included reelers andconsultants, as well as officials fromCSB, public sector banks, credit co-

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operatives, and non-banking finan-cial companies. Also present weresenior officials from DoS Karnataka,Tamil Nadu, and Andhra Pradesh.The gasifier-based oven—named‘SERI 2000 cocoon cooking gasoven’—was formally launched by anofficial from the Ministry of Textiles,Government of India (Figure 24).

Figure 24Launching of ‘SERI 2000cocoon cooking gas oven’

Into the field 77

system could be financed under the existing schemes offered by these institu-tions, and if not, what steps could be taken by the project and the manufac-turers to evolve a suitable financing scheme for the purpose.

After extensive discussions, the financial institutions said that it wasnecessary for the gasifier-based system to be formally approved by the statesericulture departments. The financiers added that once this certification wasobtained, loans could be given to reelers to purchase the devices under theirexisting schemes for acquisition of equipment.

Efforts to get DoS certification

Accordingly, between October 2000 and June 2001 a total of 12 gasifier-basedsilk reeling systems were fabricated by 2M Industries and Silk Tex at theproject’s behest. The idea was to test the systems during fabrication, andthen to install them for comparative tests against traditional cottage basins atsites to be identified by DoS Tamil Nadu, Andhra Pradesh, and Karnataka. Itwas agreed that the TERI team would study and approve the technical feasi-bility of the sites identified by the respective DoS before installing thegasifier systems.

While Silk Tex and 2M Industries set about fabricating the gasifier-basedsystems, finding suitable sites to conduct comparative tests on them provedto be a major challenge. For the tests to be meaningful, it was essential thatthe traditional cottage basins used in the DoS-selected sites met certain‘baseline’ parameters. In particular, all had to be similar in size and to burnfuelwood for heat, for only then could the project develop a standard testingprotocol for all the sites. Despite being aware of this, DoS identified reelingunits that varied greatly in terms of the sizes of basins used, design of thebasins, and the nature of fuel burned. After considerable efforts, the projectmanaged to install and commission a total of eleven gasifier-based systemsin the three states. Comparative performance tests were carried out in threesites. In all the cases, the gasifier systems performed far better than thetraditional cottage basins, as illustrated by the test results in the unit atCheyur-Avanashi, Tamil Nadu (Table 3).

While recording test data, the project team made every effort to ensure thepresence of DoS officials to ratify the results obtained. The owners of thereeling units also ratified the data. Yet, in all three states the concerned DoSdid not give the gasifier-based system a formal certificate of approval (Box 14).

Despite the absence of support from DoS, the manufacturers made sus-tained efforts to market the gasifier-based systems. Their efforts succeeded tosome extent. Seven more systems were sold to units in Ramanagaram by VEE


TABLE 3Comparison of test results between traditional and

gasifier-based ovens at Jahangir Basha’s reeling unit,Cheyur-Avanashi (Tamil Nadu)

Gasifier- Comparative improvement

Traditional based in gasifier-based oven’s

Parameter oven oven performance (%)

Average specific fuel consumption 1.91 1.00 46.83

(kg wood/kg cocoons)

Average silk yield (kg silk produced/ 10.37 10.72 3.51

100 kg cocoons processed)

Average cocoon processing rate (kg/hour) 12.45 13.02 4.44

Box 14Invisible barriers

The initial plan was to fabricate andinstall a total of 12 gasifier-basedreeling systems for comparative testsagainst traditional ovens. Testingsites were to be identified by DoSAndhra Pradesh, Karnataka, andTamil Nadu. To ensure that the reel-ing units in the DoS-chosen sites metcertain baseline criteria, it wasagreed that TERI would inspect andapprove the sites for conducting thecomparative tests. According to theagreement, DoS would arrange forthe provision of electric power to runthe gasifier systems’ blowers. How-ever, the TERI team encountered in-visible barriers in the form of delaysand ‘red tape’ that hindered the proc-ess of testing.

For instance, DoS Andhra Pradeshidentified four sites in Dharmavaramand one in Hindupur. Upon visiting

Dharmavaram, the TERI team foundthat none of the identified units hadDG (diesel generator) sets. One of theunits was not in operation because ofhigh cocoon prices. Two turned out tobe registered with KVIC (Khadi andVillage Industries Commission) andas such were not permitted to useelectric power at all. The unit atHindupur was non-existent! On itsown, the TERI team located a cottagebasin unit in Hindupur that appearedto be suitable for conducting thecomparative tests. TERI accordinglyasked DoS Andhra Pradesh to: (1) ap-prove the site identified by TERIat Hindupur for tests; (2) arrange forthe Dharmavaram units to obtain aDG set for the gasifier system’sblower, and permit the two KVIC-reg-istered units to use the DG set duringtests.

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Into the field 79

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DoS, Karnataka selected five gov-ernment-run filature units for the in-stallation of the gasifier systems:four in Chamarajanagar district(Santemarnahalli, Mamballi,Chamarajanagar, and Kollegal) andone in Davangere district (atTolhunse). The TERI team visited allthe sites. It found that the Tolhunseunit used semi-automatic reeling ma-chines and that the water-holding ca-pacity of the basin was more than100 litres—far higher than the typical20-litre traditional cottage basin. TheKollegal unit used a unique kind ofcooking basin called the Italian ba-sin. Furthermore, in all five units heatfor the ovens was supplied by a cen-tral coal-fired steam boiler! Thismade it extremely difficult to frame auniform testing protocol.

At TERI’s request, DoS Karnatakasuggested two alternative sites forthe tests: the government mini-reel-ing complexes at Jamkhandi andMudhol. Here, the TERI team encoun-tered further barriers: space con-straints, unwillingness of the reelersto participate in the exercise, lack ofelectric power or DG sets, and so on.Finally, TERI was able to identify twounits in which the tests could be car-ried out: one each in Jamkhandi andMudhol. However, both units had toprocure a separate DG set to providepower for the gasifier system’sblower. Also, the unit at Mudhol hadto provide a shed to house thegasifier system. DoS Karnataka wasinformed accordingly.

By March 2001, six gasifier-basedsystems were fabricated by Silk Tex

and installed and commissioned:three in Karnataka (Chamarajanagar,Santemarnahalli, and Mamballisites), two in Andhra Pradesh(Dharmavaram), and one in TamilNadu (Hosur). Five systems were fab-ricated by 2M Industries, of whichthree were installed and commis-sioned at sites in Tamil Nadu (Cheyur-Avanashi, Pennagram, andDharmapuri). The remaining two wereinstalled later, one each atJamkhandi and Mudhol. In each unit,TERI and the manufacturer trainedone or two persons in the operationand maintenance of the gasifiersystem.

Comparative tests were carriedout in three units: at Jamkhandi,Dharmavaram, and Avanashi. Tentests were performed in each unit inthe presence of a DoS representa-tive, the reeler, and a TERI teammember. The test results were veri-fied and ratified by all three observ-ers. The results indicated that thegasifier system yielded fuel savingsof 50%–60% and increase in silkyield of 300–350 g. Despite this,there was little progress shown byDoS in issuing a formal certificate ofapproval for the gasifier system. Asenior DoS official was transferred;other officials below him showedscant interest in following throughthe matter. In this way the processdragged on, with delays and hurdlescropping up at every turn, till it be-came apparent that DoS was not veryinterested in promoting the gasifiersystem at all.

Box 14 (Continued)


(Vijay Engineering Enterprises), Bangalore—a firm licensed by the project tomarket the systems. VEE provided the system to its client-reelers undergenerous instalment plans. In turn, financial assistance was provided to VEEby SDC. However, all the units defaulted on their instalments, and in duecourse VEE took back the systems.

What went wrong? Tangled views…

The project’s gasifier-based system had been proven in the field at Hindupur,Ramanagaram, and other clusters. The system was developed using a partici-patory approach; reelers had been involved at every stage of its evolution,and their feedback and suggestions were taken into account during its devel-opment process. The system greatly reduced fuel costs, improved the yieldand quality of silk, and reduced the cocoon processing time. With all thesebenefits, it promised a payback on investment in a mere four months. Yet thesystem failed to become popular among reelers!

Why was this so? There are no clear-cut answers to this question. Indeed,as the following examples indicate, opinions on the issue are as numerousand diverse as the stakeholders in the small-scale silk reeling industry.

Manufacturers’ views

‘We just could not compete with the subsidized reeling machines that thegovernment provides to reelers. These machines do not give much betterperformance than the traditional ovens. But they are much bigger in size;and they are being provided by the government agencies virtually free ofcost (Box 15). For most reelers, this is all that matters—low costs. Whereverwe went, reelers were very impressed with our gasifier ovens. But theywould ask us about “schemes” under which they could get the ovens…andwhen we told them our ovens did not come under any government subsidyschemes, they soon lost interest!’ (Mohan Kulkarni, 2M Industries)

‘The reelers did find it difficult to get fuelwood for the gasifier oven;specifically, dry wood chips of the correct size. But that was not the onlyreason why our gasifier oven did not sell. Nor was it the cost of the gasifieroven. After all, the oven offered fuel saving of over 50%, and besides, SDCwas putting up half the oven’s price. The main problem was that the reelerswere not prepared to invest anything…they simply wanted all the benefits,without making any efforts!’ (Balakrishna Arya, Silk Tex Industries)

‘Fuelwood was not really the issue… I offered to arrange regular supply ofdry wood-chips for reelers in Ramanagaram who bought the gasifier system.

Into the field 81

I also sold them the systems under an easy instalment plan. Despite this, thereelers defaulted on their instalments and I had to remove the systems. Themain reason why the systems failed to take off is the so-called “subsidyculture”. Reelers want to make more profits, but they want to do it withminimum effort and at minimum cost.’ (Ravi Kumar, Vijay Engineering Enter-prises)

A reeler’s view

‘The SERI 2000 gasifier oven cost 65000 rupees, which made it costly even forthe more prosperous reeler. True, the payback period worked out to barelyfour months, and the oven was being offered on instalment basis; but still,reelers were hesitant to make such a large commitment on the basis of prom-ised returns...

‘Also, from 2000 to 2003 Karnataka experienced drought-like conditions.This badly affected supply of cocoons—in terms of quantity as well asquality. At the same time, the market was flooded with Chinese raw silk

Box 15No

competition

In 2000–01, CSB developed a new‘multi-end reeling machine’ for silkreeling units. A single multi-end ma-chine can accommodate a very largenumber of reelers. Its sheer scale ofoperation places it in a category by it-self, like the charka and the cottagebasin oven.

The multi-end machine carries sev-eral features that provide a betterworking environment. For instance,the fuel is burnt in a boiler that isplaced outside the reeling unit, thusreducing the smoke within thepremises. Also, CSB provides a largesubsidy (it was 90% at one time,though this has been reduced to 50%during the Tenth Five-Year Plan) to

units that install the device. In effect,the multi-end machine becomes a‘cheaper’ alternative to the project’sgasifier-based system; a reeler canuse the former by paying virtuallynothing!

On the other hand, the multi-endmachine can process only cocoons ofvery good quality. As a consequence,very few multi-end machines can beused during the rainy season (whenthe quality of the cocoons is verypoor). This means that for a silkreeler, the multi-end machine doesnot offer as much flexibility as thegasifier-based oven or the traditionaloven, in which he can process evenlow-grade cocoons.

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imported at cheap prices. As a result, reelers suffered heavy losses. Manyunits in Ramanagaram and other clusters had to shut down. I myself shutdown my reeling unit and took up mango cultivation instead…

‘There is also a technical angle. For instance, you have to use dry woodchips of a certain size as fuel in the gasifier. In a traditional oven you can justthrow in pieces of wood of any kind or size, dry or damp! Which unit ownerwould pay more to hire a labourer to sort and chop wood into pieces of acertain size? Or find the time to supervise him?

‘Besides, if wet or poor-quality wood is burned in the gasifier oven, thechimney soon gets blackened and blocked by tar and soot. This creates a lotof smoke inside the unit, and so the chimney has to be cleaned regularly byworkers. Now, workers are paid on a batch basis. Therefore, time is veryvaluable to them. Instead of spending time cleaning the gasifier chimney,they would much rather go and work in a unit with a traditional cottagebasin oven!’ (Sukhindra Rao Babu, Ramanagaram)

A retired DoS official’s view

‘The lack of enthusiasm among reelers for the gasifier oven must be seen inthe light of developments in the silk market. The bulk import of cheap,medium-quality Chinese yarn since 2000 has been accompanied by a drop indemand for high-quality silk in the Indian market. Today, pure silk saris areno longer as popular as they once were. No doubt, the tradition of donningpure silk saris for religious and wedding ceremonies continues and willendure. Yet, ladies prefer to buy 16–20 ‘art silk’ saris at 500 rupees or so eachrather than a single pure silk sari for 10000 rupees or more…

‘The effects of this shrinkage in market demand for pure silk yarn havebeen compounded by the drop in supply of good quality cocoons from 2000onwards because of drought. Traders now pay almost the same price for bothfine and medium-quality raw silk. Naturally, small-scale reelers have beenbadly hit by these developments. Many units have shut down. It no longermakes sense for the remaining reelers to spend more money on buying high-quality cocoons, or more time and effort in making high-quality silk yarn.There is a clear shift in focus among them: from producing quality to produc-ing quantity…’ (V L Krishnamurthy Rao, retired Inspector, Technical ServiceCentre, DoS Karnataka)

A silk expert’s view

‘There are many complex reasons for the silk reeling industry’s losses. Ofcourse Chinese yarn imports have depressed the Indian silk market…but then

Into the field 83

Chinese silk is blamed for almost everything that goes wrong in the Indiansilk industry! I have read Tariff Committee Reports of the early 1900s inwhich references are made to complaints by Indian reelers against the large-scale import of Japanese silk yarn. So, the issue of “foreign silk” affecting thefortunes of Indian silk reelers goes back over 100 years, when India wasunder British rule!

‘Besides Chinese silk and the drought that reduced cocoon supplies from2000 onwards, another event affected the fortunes of small-scale reelers inRamanagaram and elsewhere. This was the Kargil war of 1999 and its after-math. A large volume of silk goods—raw yarn as well as finished products—travels over land from India to Pakistan through “unofficial” trade routes viaGujarat and Punjab. The Kargil war, and the tightened security on the bor-ders in its wake, blocked these unofficial trade routes. The result: a glut ofsilk goods in the Indian market, which lowered the prices of raw silk…

‘It is also important to recognize the very strong and ancient linkagesbetween reelers and weavers clusters. For instance, the Ramanagaram reelingcluster is very closely linked to the Varanasi weaving cluster. If for somereason the Varanasi weavers are unable to sell their products—as whenborder routes to Pakistan were sealed in the years after the Kargil war—theripples are directly and immediately felt by the Ramanagaram reelers.’(T S Nagaraja, silk technologist)

A fuel supplier’s view

‘The costs of wood have little to do with the misfortunes of the silk reelers.Five years ago (in 2000–01) I used to sell anything between 35 and 50 tonnesof fuelwood each day to silk reelers. I used to charge them 950 rupees to 1100rupees per tonne of wood. But many reeling units have shut down sincethen. Today I sell just around 8–10 tonnes per day to reelers; I make up byselling fuelwood to hotels, restaurants and the like. But the price of my woodis still around 1000 rupees per tonne…’ (Abdul Aziz, wood merchant,Ramanagaram)

Untangling the threads

In a sense, the complex challenges faced by the project in developing andpromoting its gasifier-based reeling system are reflected in the diverse rea-sons cited for the system’s failure to become popular. Some of these reasonsare tangible: imports of cheap Chinese silk, drop in the prices of yarn, short-fall in supply of good-quality cocoons, and so on. Others are more subtle: for


instance, the ‘subsidy culture’ among silk reelers. Although the governmentsubsidy system is well-intentioned, over the decades it has created interestsand a certain inertia within the establishment and among reelers that resistattempts to innovate and to change.

This tendency has only been strengthened by the intrinsically low-profitnature of small-scale reeling activity.14 Table 4 shows a cost analysis of atypical (traditional) cottage basin unit, with daily net profit of 203 rupees.The table shows the vital role played by earnings from silk wastes and pupaein making reeling operations viable. It can be seen from the table that ifcocoon prices increase by a mere 3% (from 160 rupees to 165 rupees per kg),the unit will start to incur a daily loss of 297 rupees (case ‘A’). Similarly, ifyarn prices fall by just 2% (from 1400 rupees to 1375 rupees per kg), the unitwill incur a daily loss of 109 rupees (case ‘B’). Table 5 shows the benefitsbrought about by using the gasifier-based system instead of the traditionalcottage basin oven.

There was also another subtle factor—an internal one—that had somebearing on the outcome of the project. Till 1997, the development of gasifier-based technology for silk reeling was part of an action research projectwithin the E&E (energy and environment) sphere of SDC’s Country Pro-gramme for India (1996–2003). The action research mode allowed SDC to beinvolved side by side with TERI in the project, with the focus of activitiesbeing on increasing energy efficiency. It permitted flexibility in approach toproject-related issues, and helped both partners take decisions and resolveproblems in a swift and effective manner.

In mid-1997, SDC and the Ministry of Textiles, Government of Indiasigned an agreement to implement a five-year sericulture programme calledSERI 2000. This was an innovative programme involving both the public andprivate sectors. With the action research project on gasifier-based silk reelingtechnology showing promise, there was an internal debate in SDC onwhether the project should continue in the action research mode or be movedto the SERI 2000 programme and thereby allow it a broader exposure. It wasdecided to choose the latter option, and so SDC shifted its project-related

14 Dr Urs Heierli of SDC observed in 1997 that a technology to improve energy efficiency (such asthe gasifier-based system) would succeed only if it was a ‘Factor Four’ technology (i.e., one thathalved the costs and doubled the benefits). The idea behind ‘Factor Four’ is that natural resourcescan be used more efficiently by generating more products and services from available resources onthe one hand, and by using less resources to maintain the same standards/quality of life on theother. The idea was first put forward by Ernst Ulrich von Weizsacker et al. in the book Factor Four:Doubling Wealth, Halving Resource Use (1997, Earthscan Publications Ltd, London).

Into the field 85

TABLE 4Cost analysis of a traditionalcottage basin reeling unit15

Case A: Case B:

cocoon price yarn price

Total rises from falls from

Cost cost Rs 160/kg to Rs 1400/kg to

Particulars Quantity (Rs/unit) (Rs) Rs 165/kg Rs 1375/kg

Daily INPUT

Raw materials

Cocoons required per day (kg) 100 160 16 000 16 500 16 000

Total raw material costs (1) 16 000 16 500 16 000

Wages and processing costs

Reelers 10 70 700 700 700

Cookers 5 65 325 325 325

Re-reelers 1 100 100 100 100

Supervisor 1 100 100 100 100

Assistants 2 65 130 130 130

Electricity charges per day (rupees) 32 32 32

Water charges per day (rupees) 100 100 100

Wood required per day (kg) 200 1.5 300 300 300

Total wages + processing costs (2) 1 787 1 787 1 787

Total daily input costs (1 + 2) 17 787 18 287 17 787

Daily OUTPUT

1. Silk 12.5 1400 17500 17500 17187.5

2. Silk waste (jute) 2.2 200 440 440 440

3. Pupae 10 5/basin 50 50 50

Total daily earning (1 + 2 + 3) 17990 17990 17677.5

Net profit/loss per day (+/–) (+) 203 (–) 297 (–) 109.5

support and monitoring mechanisms from the E&E sphere to the SERI 2000programme. Under SERI 2000, SDC worked directly with the Ministry ofTextiles, Government of India. Other government bodies such as CSB toobecame involved. The project functioned smoothly so long as SERI 2000covered pre-cocoon as well as post-cocoon areas. Later, however, SERI 2000shifted its main focus to pre-cocoon areas and livelihood issues, becauseSDC’s Country Programme itself had changed its orientation. As a result ofthis shift in focus, new and complex dynamics came into play in areas relatedto the SDC–TERI project. Objectives became blurred and there was a loss of

15 Rentals are assumed to be nil.


TABLE 5Comparative cost analysis of gasifier-based

system with traditional oven

Traditional cottage basin Gasifier-based system

Total Total

Cost cost Cost cost

Particulars Quantity (Rs/unit) (Rs) Quantity (Rs/unit) (Rs)

Daily INPUT

Raw materials

Cocoons required per day (kg) 100 160 16 000 100 160 16 000

Total raw material costs (1) 16 000 16 000

Wages and processing costs

Reelers 10 70 700 10 70 700

Cookers 5 65 325 5 65 325

Re reelers 1 100 100 1 100 100

Supervisor 1 100 100 1 100 100

Assistants 2 65 130 2 65 130

Electricity charges per day (rupees) 32 48

Water charges per day (rupees) 100 100

Wood required per day (kg) 200 1.5 300 90 1.5 135

Total wages + processing costs (2) 1 787 1 638

Total daily input costs (1 + 2) 17 787 17 638

Daily output

1. Silk* 12.5 1400 17 500 12.9375 1400 18 112.5

2. Silk waste (jute)* 2.2 200 440 1.7625 200 352.5

3. Pupae 10 5/basin 50 50

Total daily earning (1 + 2 + 3) 17 990 18 515

Net profit/loss per day (+/–) (+) 203 (+) 877

* The gasifier-based system yields 3.5% (0. 4375 kg) more silk due to renditta improvement; hence,

the yield of silk wastes is lower by a corresponding weight.

flexibility in policy and decision-making, which had a negative impact on theoutcome of the project.

Siddlaghatta yarn: low-cost approach

In 1998–99, even as the Mark 3 system was undergoing comparative tests inPasha’s and Babu’s units in Ramanagaram, the project decided to explore thepotential for biomass gasifiers in other silk reeling clusters. The projectcommissioned a study of the Siddlaghatta cluster by T S Nagaraja, similar to

Into the field 87

the study he had earlier conducted in Ramanagaram. The study establishedthe following points.� The average reeling unit in Siddlaghatta is much smaller than at

Ramanagaram.� Siddlaghatta units use a special kind of vessel—known as an ‘Italian’

basin—to cook cocoons. One Italian basin serves cocoons to two reelingbasins located in the same masonry structure called ‘table’ (Figure 25).

Figure 25Conventional Italian oven:(a) front view; (b) side view

(a)

(b)


� The typical reeler operates four to six Italian basins (compared to eightcottage basins in Ramanagaram).

� On an average a reeling unit burns about 100 kg fuelwood a day to proc-ess 36–54 kg cocoons.

� The Siddlaghatta units produce silk of especially fine quality because theiroperating practices, layout, and equipment are different from units inother clusters.

Siddlaghatta silk has certain special characteristics and fetches a premiumin the market. Understandably, traders direct the best quality cocoons to theSiddlaghatta cocoon market.

From its ongoing experience in Ramanagaram, the project team realizedthat an integrated gasifier-based cocoon cooking system for Siddlaghattaunits would take time to develop and was likely to be a costly option forreelers. The team was also aware that Siddlaghatta silk owed its superiorqualities to the unique layout andoperating practices of the Italian basinunits. The team therefore proposed toSERI 2000 that in developing a gasifiersystem for Siddlaghatta units it wouldnot interfere with the layout of the Italian basin units, or change the basicdesign of the Italian oven in any way. Instead, it would focus its efforts onlyon ‘retrofitting’ the existing Italian oven with a suitable gasifier. Thus, theproject’s approach in Siddlaghatta was driven by the principle of ‘retrofit atlow cost’.

Technology: silk and spice routes converge

Annexure 5 describes in detail the process of developing gasifier-basedtechnology for the Italian oven. In 1996–97, an updraft wood gasifier systemhad been developed by TERI for large cardamom curing in Sikkim. Thissystem became the model for the prototype Siddlaghatta updraft gasifier.

As a first step, the project fabricated and tested a laboratory prototype—Mark 0—at Gual Pahari. The tests showed that the Mark 0 gasifier wascapable of supplying as much heat as the existing Italian oven, and that too,with 30%–40% less consumption of fuelwood. Thereafter a field prototype—Mark 0-F—was designed, fabricated, and successfully tested at Gual Pahariin May 2000.

The project’s approach inSiddlaghatta was driven by theprinciple of ‘retrofit at low cost’

Into the field 89

Selection of testing/demonstration sites

The project requested DoS, Karnataka to help in identifying sites where Mark0-F could be field-tested. In September 2000, officials attached to the Techni-cal Service Centre, DoS at Siddlaghatta assisted the project team in identify-ing two units as field-test sites. One unit was owned by B M Gurumurthyand the other by Anantha Padmanabha.

Ensuring fuel supply

To ensure a regular supply of fuel during the trial period, the project teamsurveyed sawmills and briquette plants in and around Siddlaghatta. Onebriquette plant was located on the outskirts of the cluster, but it had beenlying closed for a while; besides, the briquettes in the market were quitecostly at 1600–1800 rupees per tonne, as against 1400 rupees per tonne forcut-wood (2000 prices). Finally, the project located two sawmills—inVijayapura and Chickballapur—which agreed to supply cut-wood of therequired size at 1400 rupees per tonne.

Proving the systems

In November–December 2000, two updraft gasifier systems were fabricatedby 2M Industries, Mumbai under the guidance of TERI’s technicians, trans-ported to Siddlaghatta via Bangalore, and installed at the two sites. At thispoint in time, local supply of cut-wood had still not been arranged for;hence, dry cut-wood pieces were purchased from a sawmill in Ramanagaramand transported by van to Siddlaghatta.

Comparative performance tests started in late-February 2001 and contin-ued till June (see Annexure 5). There were occasional interruptions in thetests when the units closed down because of the scarcity of good-qualitycocoons in the market, or because of labour problems. In all, data weregathered for 17 days’ operations in Gurumurthy’s unit and 37 days inAnantha Padmanabha’s unit. Analyses showed that the gasifier systemreduced fuelwood consumption by 38.5%–42.5%, improved the quality ofyarn, reduced renditta (that is, increased silk yield), and improved workingconditions by reducing smoke and other emissions.

A simple cost–benefit analysis was done for the gasifier system. With anestimated cost of around 15000 rupees, it promised a payback of 18–26months based on fuelwood savings alone. If the increased earnings due tobetter silk yield were taken into account, the payback period worked out to amere 6–12 months.


Meeting users’ needs

In June 2001, SDC and TERI organized a project-cum-design review work-shop at Siddlaghatta (Figure 26). Several reelers participated, along withmanufacturers, media persons, and government officials. A few suggestionswere made to further improve the gasifier system. In particular, reelersexpressed the need for charcoal to dry the silk yarn. Traditionally, theyextracted hot charcoal from the oven and placed it below the reeling shaft todry the moist yarn as it was reeled; but the gasifier system produced little orno charcoal.

Figure 26Design review workshop at Siddlaghatta:

(a) workshop in progress; (b) field visit

(a)

(b)

Into the field 91

Hot plate–hot air system

Following the workshop, a project coordination committee or PCC was setup comprising representatives from SDC, TERI, DoS Karnataka, and reelersincluding Gurumurthy and Anantha Padmanabha. The first PCC meetingwas held in August 2001, during which it was decided that the project woulddevelop a yarn-drying system and test it first at Gurumurthy’s unit, sincethis unit had more space and an additional set of Italian basins for trials.

Thereafter, the project team modified the gasifier system so that heat fromthe flue gases could be used to dry the moist silk yarn. Two systems weredeveloped: a ‘hot air’system and a ‘hot plate’ system. These systems weretried out, first at Gual Pahari and then at Gurumurthy’s unit. In October2001, a second PCC meeting was held to obtain reelers’ feedback on the twoyarn-drying systems. The reelers felt that for the drying process to be mademore effective the project should try to combine the two systems, that is, todevelop a ‘hot plate–hot air’ system. Accordingly, the project successfullydeveloped such a system and installed it at Gurumurthy’s unit (Figure 27).

As mentioned earlier, at the June 2001 workshop reelers had voiced theirneed for charcoal with which they could dry the moist yarn. Modificationswere therefore made in the gasifier to enable it to produce charcoal as andwhen necessary. The reelers could extract the charcoal and use it in thetraditional way to dry yarn.

Heat recovery unit

In the conventional charka and Italian basin units in Siddlaghatta, three tofour batches of cocoons are processed daily. Once a batch of cocoons hasbeen processed, the basins are again filled with fresh water at room tempera-ture. Workers have to wait while this water is heated up to 90–92° C, for onlythen can they commence the cooking and reeling of the next batch of co-coons. On an average, the waiting time ranges between 20–25 minutes.Hence, besides valuable heat energy a considerable number of valuableworker-hours are lost each day in between batches. The waiting time can bereduced or eliminated if hot water is readily available to refill the basins atthe end of a batch. This is possible if waste heat is properly used.

In late-2002, a chance event led TERI to fabricate a heat recovery unit orHRU for a charka unit in Siddlaghatta (Box 16). The HRU is simple in design:a ‘tube-in-tube’ heat exchanger, which transfers heat from the hot flue gasespassing through one tube to water at room temperature flowing in the sec-ond tube. The resulting hot water can then be drawn and used to refill cook-ing/reeling basins. The HRU is designed in such a way that it can be addedon or ‘retrofitted’ to a traditional Italian basin or charka oven (Figure 28).


Figure 27Options to dry silk yarn by recovery of waste heat from oven:

(a) hot air; (b) hot plate; (c) hot plate–hot air

(a)

(b)

(c)

Into the field 93

Figure 28Layout of HRU (heat recovery unit):(a) schematic; (b) field installation

(a)

(b)


Box 16A hotidea

One day, while examining the chim-ney in a charka unit in Siddlaghatta, Iaccidentally burned my fingers. Onlythen did I realize how much heat wasbeing carried away by flue gases—andhow much potential there was to usethis heat to pre-heat water for thecooking basins!

I used GI (galvanized iron) sheetsto make a simple heat recovery unitor HRU—the first of its kind. But thewelded strips started to rust, andflakes of rust fell into the basin be-neath, discolouring the water as wellas the silk. To solve this problem Imade the HRU from SS (stainlesssteel) sheets instead of GI sheets.

The HRU provides a large volumeof hot water—much more than isneeded by the cooking/reeling ba-sins. Reelers, workers and othersnow draw hot water from HRUs for allkinds of purposes—washing theirhands and feet, cooking, cleaningutensils, washing clothes, and so on.There is another advantage with theHRU: it greatly reduces radiant heatfrom the chimney. I have heard work-ers complain about having to sit nearhot, conventional chimneys whiletheir colleagues work in comfort nextto ‘cool’ HRUs…

Y NagarajuTERI

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The HRU enables pre-heating of water up to 80 °C. Thus, very little addi-tional time or energy is needed to heat up the water to the required 90–92 °Cfor the Italian cooking/reeling basins. TERI’s estimates are that the HRUachieves fuel savings of at least 22%. According to reelers and others, how-ever, the savings are as high as 40%–50%. An additional benefit of the HRU isthat it drastically cuts down radiant heat from the chimney’s surface, therebygreatly improving the working environment.

Mixed results…

To give wider publicity to the gasifier, the yarn-drying system and the HRU,the project organized a ‘launching workshop’ in Siddlaghatta in May 2003.Over 40 reelers participated in the workshop, along with manufacturers andofficials from DoS, Karnataka. The manufacturers—2M Industries and VEE—announced their prices for the gasifier system and ancillary components invarious configurations (Figure 29). For instance, the basic gasifier system

Into the field 95

(including blower and burner) was priced at 19250 rupees, offering a pay-back within 3–6 months; with the hot plate–hot air system included the pricewas 31000 rupees, offering a payback of between 8–15 months. The HRU byitself cost barely 3000 rupees.

In spite of its relatively low price and its proven benefits, however, theSiddlaghatta gasifier did not become popular. In retrospect, there were anumber of reasons for this. Although relatively low priced (19250 rupees)when compared to the Ramanagaram system (65000 rupees), theSiddlaghatta gasifier was not developed in the systematic stage-by-stage,participatory manner that the project had followed in Ramanagaram. Feed-back on the gasifier system’s performance was largely obtained from just tworeelers—Gurumurthy and Anantha Padmanabha. Except for the launchingworkshop of 2003, few efforts were made to market the system or to publi-cize its benefits among other units in the cluster. Indeed, the project teamrealized that a sustained presence in the field was necessary to promote thesystem among reelers. However, by 2003 the SERI 2000 programme itself had

Figure 29A view of the improved gasifier-based

system for the Italian oven


ended, and there was no scope for the team to maintain a continuous pres-ence in the cluster.

Yet, these reasons by themselves are not sufficient to explain why theSiddlaghatta gasifier failed to replicate. At a deeper level, the project’s effortsin Siddlaghatta were stalled by the same invisible yet formidable barriersthat thwarted their efforts in Ramanagaram. These barriers included thewidespread apathy and lack of initiative among reelers brought about bydecades of ‘subsidy culture’; the intrinsically low-profit nature of small-scalesilk reeling activity, which made it hard for even the more enthusiasticreelers to find the financial resources to acquire improved technology; thecorresponding lack of enthusiasm among financial institutions to advanceloans to reelers; and the crippling losses suffered by the reeling industry due

Figure 30Several heat recovery units installed

at an Italian basin unit in Siddlaghatta

to a variety of factors includ-ing shortfall in the supply ofgood-quality cocoons and thefall in market demand for rawyarn.

On the other hand, theHRUs have proved far morepopular in the cluster (Box17). At present, an estimated30–35 HRUs are being used bycharka and Italian basin units,without any subsidy support,in Siddlaghatta (Figure 30).

Rewinding the reel—abarrier analysis

In both Ramanagaram andSiddlaghatta, the projectshowed that biomass gasifiertechnology could halve fuelcosts and simultaneouslyimprove silk yield; but it washard to popularize the tech-nology among reelers. This,despite the fact that thegasifier-based system had

Into the field 97

proven its viability in terms of a four-month payback—not by mere calcula-tions or projections on paper but by concrete quantification of field perform-ance for over 18 months endorsed by the reelers themselves! To understandthe reasons why the new technology was not adopted by reelers, one has tolook into the socio-political web within which the silk reeling industry, andindeed the entire SMiE sector, finds itself entangled in today’s times.

The overall industry outlook for sericulture is not very strong, comparedto (for example) consumer goods or export items. Most of the silk itemsproduced cater to domestic demand, which does not have a high growthrate. The profit margins of reelers are quite slim and indeed hover close tozero (see Tables 4, 5) because the reeler does not have any control over eitherthe cocoon price or silk yarn price. On top of this, the continuous droughtfrom 2000 onwards, coupled with the advent of high-quality low-pricedChinese silk, has made reeling a highly volatile business with many reelersopting out of it. This kind of atmosphere is not conducive to any risk-takingor experimentation with new products or technologies.

The multitude of government bodies controlling the silk industry—bethey CSTRI, CSB, or other central and state-level bodies—generally do notseem to be enthusiastic about any initiatives other than their own. While theproject was trying to market the ‘SERI-2000 cocoon cooking gas oven’ as acommercial piece of equipment, CSTRI launched its multi-end reeling ma-chine with a huge subsidy. Inevitably, comparisons were made and prefer-ences expressed, to the disadvantage of the SERI 2000 oven.

Box 17Cheap

and best

V L Krishnamurthy Rao, a retired DoSofficial, is not surprised that the HRUhas become popular while thegasifier system did not find custom-ers. ‘The gasifier system for the Ital-ian oven, developed after so muchresearch, costs around 20 000 ru-pees. It gives fuel savings of 40%–50% but it is bulky, difficult toclean, and requires an air blower to

operate—which means dependenceon electric power either from themains or from a kerosene genset. Incontrast, TERI’s HRU costs a mere3000 rupees, needs no electricpower, little maintenance…yet it toogives considerable fuel saving, be-sides plenty of hot water to use for allkinds of household purposes!’

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Also, the project envisaged that the ‘financing’ route could cut some icewith the reelers. The bankers, however, suggested certification of the newgasifier-based oven by sericulture departments as a first step. As describedearlier, the project struggled for nearly two years to obtain the necessarycertification through comparative performance monitoring, but despite theproven benefits of the gasifier-based ovens the efforts were in vain.

Associated with the general inertia of the sericulture sector is the risk-averse, ‘waiting-for-sops’ attitude of the reelers. Concepts such as ‘paybackperiod’ and ‘internal rate of return’ are daily mantras of the corporate world,yet they seem to mean little to the silk reelers. Indeed, the reelers’ frame ofreference just does not have space for such things. On the one hand theyseem to understand perfectly the government ‘schemes’ under which silkreeling equipment is promoted with subsidies that ensure the reelers have topay almost nothing in real terms. On the other hand, they understand andreadily purchase ultra-low cost equipment like the HRU promoted inSiddlaghatta by private entrepreneurs. In either case, they end up payingvery little or no money. In effect, the reelers’ mantra is: pay little or nothingbut expect the maximum benefits.

In general, reelers do not invest capital in new equipment; they prefer tobuy second-hand items. This kind of entrepreneurial behaviour—to look forgovernment sops or for ‘low-hanging fruit’ —seems to be prevalent acrossthe SMiE sector, and poses immense challenges when attempts are made toanalyse the market potential or draw up marketing plans for new technol-ogy. The entrepreneur forms a mental idea of how much he can or is willingto pay for a given piece of equipment, but does not normally share this withthe equipment seller. The latter then has to make an informed or ‘wise’ guessof how much the entrepreneur is willing to pay, and work backwards! It isotherwise hard to explain why a piece of equipment that pays for itself infour months could not find takers.

The hurdles outlined so far can be collectively thought of as sector-specificinstitutional barriers. But then it was not as though the project was unawareof these barriers. From the very early stages of the project Dr Urs Heierli,then Country Coordinator of SDC-India, was keenly aware of the scant profitmargins of the reelers; he was the first to suggest drying of pupae as it couldfetch additional income for the reeler. Indeed, Dr Heierli was champion ofthe concept of ‘poverty alleviation as a business’ (Box 18).16 SDC, at that time,

16 Heierli U. 2000. Poverty Alleviation as a Business: the Market Creation Approach to Development.Berne, Switzerland: Swiss Agency for Development and Cooperation.

Into the field 99

Box 18Poverty alleviation as a business, technology as

a tool, and market creation as an approach—a niche for development cooperation?

In his book ‘Poverty alleviation as abusiness’, Dr Urs Heierli makes aneminent case for a market creationapproach to development vis-à-visconventional approaches that chan-nel down funds via government orNGOs to the so-called ‘beneficiaries’through public infrastructure. In themarket creation approach, the focusis on three areas:� need-based product development;� marketing and promotion; and� creation of a sustainable market.

of a technology are always ‘elite’ andthe poor are among the followers.Consequently, sales pick up veryslowly and hence the marketing agen-cies will incur ‘losses’ for the first 5–10 years. Profits will come much laterwhen sales pick up, as shown in Fig-ure 31. Dr Heierli argues that the

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Examples of suc-cess stories quotedfrom Bangladesh, Ne-pal, India, and CentralAmerica in the produc-tion and marketing of‘products’ include thefollowing:� treadle pump;� ‘Postcosecha’ silos;� micro-concrete

roofs;� rope pump for pri-

vate drinking waterpumps;

� low-cost private la-trines; and

� tree plantation as asocial insurancescheme.

Dr Heierli points outthat the early adopters

Figure 31Different phases and effects

of the product cycle


was unique in supporting technology development and market creation astangible means of fighting poverty. In fact even the charka reelers, most ofwhom were below the poverty level, were seriously considered for technol-ogy intervention. However, gasifier technology for loose biomass (the fuelprimarily used by charka reelers) was not yet mature and hence the idea wasput aside for a later date.

However, this entire approach—of technology development and marketcreation as one of the main planks for development cooperation—was taper-ing off within SDC around the time when the SERI 2000 programme wasbeing operationalized. This created some kind of void in conceptualizingmarket creation activities. Also, the project team within TERI, which was socreative in participatory technology development and in hands-on fieldwork,could not gear itself up to the daunting (and unfamiliar) task of marketpromotion on its own. There was no clear understanding or strategy withinthe TERI team on how to market the new technologies outside the ‘projectexecution’ frame.

Box 18 (Continued)○

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losses incurred in the early phases ofproduct development, test marketing,etc., may never be recovered andshould be offset by donor funding.Some of the products identified ashaving a high potential are:� solar lanterns;� wood gasifiers; and� solar water disinfecting devices.

The basic argument of Dr Heierli—to subsidize the marketing effortsrather than the product cost—caneasily be extended to a large numberof ‘subsidy’ schemes of the govern-ment such as biogas plants, im-proved chulhas, water-pumping

windmills, etc. In the case ofsericulture, the ‘economic ovens’ inthe earlier World Bank-supportedproject and the multi-end reeling ma-chines were subsidized. If the SERI2000 project had worked with the‘market development’ spirit, the SERI2000 gasifier-based cocoon cookingoven could probably have taken off.The later successes of gasifiers showthat the biomass gasifier is indeed aproduct with high potential. However,adequate market development ef-forts—including establishment of asupply chain, service network, qualitycontrol, and so on—are yet to bemounted.

Into the field 101

The ‘early adopters’ who are so crucial to the success of any new technol-ogy were hard to find for the project’s gasifier-based silk reeling technology.There were some like ‘Chennapatna Ravi’, an innovative reeler with consid-erable influence in the Chennapatna cluster, but the TERI team was unable toexploit the opportunities because the team members were inexperienced inhandling such people. Besides, project personnel were not present continu-ously in the field after the demonstration of the gasifier systems. This cer-tainly prevented the gasifier systems from becoming more popular. Perhapsthe team should have identified local consultants who could have taken careof maintenance and trouble-shooting tasks, and thereby helped build bondsof trust and credibility with the reelers.

The project could also have1 developed a lower-cost option to ‘break the ice’ with reelers (such as

retrofitting existing ovens with a common cooking bath and with acheaper, updraft gasifier); and

2 adopted innovative marketing methods such as selling energy servicesrather than equipment.

However, there was no space in the project to attempt these efforts. SERI2000 itself shifted focus to pre-cocoon areas and to livelihood issues. In asense, all the important players—the government bodies, SERI 2000 team,TERI team, reelers and others—were working at cross-purposes. There was adefinite breakdown of communication among the players, and the process ofdecision-making became less and less transparent within the project.

To sum up, the main barriers encountered by the intervention in the silkreeling sector can be categorized as:� sector-specific institutional barriers;� sector-specific socio-cultural barriers;� lack of strategic and unified thinking on market promotion of new tech-

nologies;� shift in focus away from technology; and� breakdown of communication among the project partners.

Most of these barriers exist even today. They are complex and intertwined;they cannot be addressed in isolation; but they must be overcome if we wishto use energy-efficient technology to bring about socio-economic develop-ment among the small-scale silk reeling enterprises.


S I LK DYE ING

In 1997, even as the prototype gasifier-based reeling ovens were being field-tested in Ramanagaram, the project sought other areas in the sericulturesector in which to apply the principles of gasifier technology.

After extraction from cocoons by reelers, raw silk yarn is woven intofabric. The raw yarn/fabric usually contains natural colouring matter thathas to be removed by bleaching to make pure white silk. If coloured silk isrequired, the raw yarn/fabric is first bleached and then dyed to impart theappropriate hue to it. Both bleaching and dyeing operations are carried outby small-scale dyeing units, using tanks containing hot water and chemicals(Box 19). There are an estimated 2000 dyeing units located in clusters inurban and semi-urban areas such as Bangalore, Doddaballapura,Kanchivaram, and Mudireddypalli.

The silk dyeing industry is much more organized in its operations thanthe silk reeling industry. Dyeing units have much better profit margins thanreeling units, and operate on a purely commercial basis. Hence, they aremuch less affected by government policies related to subsidies, imports, etc.

However, one critical area of a dyeing unit’s operations is fuel. Tradition-ally, dyeing units burned fuelwood in their ovens to heat up the bleaching/dyeing tanks. The ovens were badly designed, and burning fuelwood inthem emitted very large amounts of smoke. In the face of ever-growingcomplaints from local residents, dyeing units progressively switched over toburning petroleum-based fuels such as kerosene and diesel. While these fuelsreduced the levels of pollution to some extent, air blowers were required toburn the fuels fully—which meant additional expenditure and increaseddependence on electric power for the blowers.

With the hike in prices of diesel (and to some extent, kerosene) at the turnof the century, the profits of dyeing units dropped sharply. Most dyeing unitsoperated on a job-order basis. Hence, the only way they could increase theiroperating margins was to reduce their fuel costs. The project saw one possi-ble way by which dyeing units could do this—by using wood gasifiers.

Development of gasifier-based dyeing oven

As mentioned earlier, in 1997 the project commissioned BIET to do a study offabric dyeing units in south India to get a better picture of the industry. Thesurvey team visited three different dyeing clusters: Kanchivaram, Tirupur,and Bangalore. The main findings of the study are listed below.

Into the field 103

Box 19Ways to dye

Three kinds of operations are carriedout in a small-scale fabric dyeingunit: (1) bleaching, (2) body dyeing,and (3) contrast dyeing (Figure 32). Atypical dyeing unit has two tanks.Usually, bleaching is done in one tankand dyeing in the other. However, de-pending on the nature of the job andthe time constraints, both operationsmay be carried out one after theother in the same tank.� In bleaching or ‘discharging’, the

fabric is immersed in a tank con-taining a solution of chemicals inwater, known as bleaching liquor,to remove all traces of natural col-ouring matter from it. The whitefabric is then ready for dyeing withappropriate colours, if required.

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� Body dyeing imparts a specific col-our to the entire fabric (usually, sa-ris). A suitable dyeing liquor isprepared in the tank. The tank isheated, and the saris to be dyedare placed in the hot liquor inbatches (numbering between1–25 saris). Periodically, the col-our of each sari is checked by dry-ing small portions of its fabric onthe hot chimney surface.

� Contrast dyeing is carried out toimpart a specific colour to only cer-tain portions of the fabric. Sarisare contrast-dyed one at a time;during each operation, polythenesheets are used to shield portionsof the sari that are not meant toabsorb the colour.

Figure 32Operations in a dyeing unit: (a) bleaching;

(b) body dyeing; (c) contrast dyeing

(a)

(b)

(c)


� Both the dyeing process and the time taken for it vary from cluster tocluster.

� Temperatures in the dyeing tanks vary in different clusters.� In general, each unit uses a pair of vessels—one for bleaching and the

other for dyeing.� Some clusters, such as Bangalore, undertake both fabric dyeing and yarn

dyeing, while others such as Kanchivaram focus on yarn dyeing alone.� Yarn dyeing units are usually large-scale operations. The units are con-

gested, with very little space to install a gasifier system. In contrast, fabricdyeing units are usually medium-scale in operations, and they have roomin which to accommodate gasifiers.

The project therefore decided to develop a wood gasifier system to pro-vide heat for fabric dyeing units. During the BIET survey, many units ex-pressed their willingness to provide space for the demonstration of a gasifiersystem. The project finally selected Pallavi Process, a fabric dyeing unit inBangalore, for the installation and testing of the gasifier system.

To obtain baseline data, a detailed energy audit was conducted of twodyeing units—Pallavi Process and Shilpa Silk Prints. In March 1998, a labprototype gasifier oven for dyeing was developed and tested at TERI’S GualPahari campus. The lab prototype had two water baths or vessels, to matchthe pair of tanks used in the conventional dyeing oven. To enable easy fabri-cation, the lab prototype was made entirely of metal—mild steel and stain-less steel. Tests showed an average thermal efficiency of 42% (compared toaround 23% for the conventional oven).

The next step was to fabricate a field prototype and test it at Pallavi Proc-ess. The project decided to make the oven portion of the field prototype atthe unit itself, and with masonry instead of metal. There were three reasonsfor this: (1) the metallic surfaces of the lab prototype had attained very hightemperatures during tests; (2) dyeing units would be far more comfortablewith a masonry structure resembling the conventional oven; and (3) it wouldbe difficult to transport a large, heavy metallic structure from Delhi toBangalore.

The field prototype was fabricated and installed at Pallavi Process inAugust 1998 (Figure 33). Tests were conducted to compare its performancewith the existing oven. The results showed that the field prototype had anoverall thermal efficiency of 46%—more than double that of the existingoven. This clearly indicated that a minimum of 50% fuel savings could beachieved by using a gasifier-based dyeing oven.

Into the field 105

Figure 33Gasifier-based dyeing system:

(a) schematic; (b) system in operation

(b)

(a)


During the field prototype trials, the dyers at Pallavi Process suggested anumber of modifications in the system that were carried out by the project.Thereafter, the modified field prototype was tested and data gathered tocompare its performance with that of the existing oven. This was no easytask! In general, the dyeing processes are very complex; different operationsare carried out in the same tank/vessel, and no standard procedures arefollowed by units. (It is noteworthy that even variations in colour have animpact on fuel consumption; typically, dyeing with light colours requires lessheat than dark colours!) Orders were received and executed on a daily basisby Pallavi Process, demanding different colours and operations in each case.Within a single job itself, varying amounts of fabric were processed perbatch, making it extremely difficult to make comparisons between thegasifier-based oven and the conventional oven at any point of time. Also, in1999 there was a recession in the fabric dyeing business, and Pallavi Processoperated for only about 15 days each month for several months. This pre-vented the smooth conduct of tests.

From December 1999, though, the dyeing industry witnessed a revivaland the unit functioned on a regular basis. Ten comparative test runs werecarried out between January and March 2000—six on body-dyeing, and twoeach on bleaching and contrast dyeing. Data were gathered on fuelwoodconsumption, materials processed, and water consumed. The results showedthat the gasifier-based oven yielded fuel savings ranging between 40% and55%; increased fabric processing rate by up to 15%; and reduced water con-sumption by up to 22%. With the successful demonstration of the gasifier-based oven, the time had come to find suitable manufacturers for the system.

Manufacture and marketing

To make the gasifier-based dyeing system, a manufacturer requires skillsdifferent from those needed to make a cocoon cooking/reeling system. In thelatter case, the system can be made as a package for a given capacity, and itcan be fabricated completely in a workshop as site work is minimal. How-ever, a silk dyeing system needs metal fabrication work off-site, as well asmasonry work on site. One single manufacturer generally does not have allthese skills. A manufacturer–civil contractor–marketing team has to workclosely and in coordination to make and install a gasifier-based dyeingsystem.

TERI entered into agreements with both 2M Industries and Silk Tex tomanufacture the gasifier-based dyeing systems. The first gasifier-based

Into the field 107

dyeing system was made by Silk Tex and installed for demonstration atSurya Pvt. Ltd under TERI’s supervision. However, although the systemperformed well, Silk Tex did not succeed in tying up with firms who couldtake charge of installation, commissioning, and civil works. The firm thereaf-ter lost interest in manufacturing any more gasifier-based dyeing systems.

The Mumbai-based manufacturer, 2M Industries, collaborated with VEEto market its gasifier-based dyeing systems. In turn, VEE collaborated withNishant Architects for civil work. TERI trained VEE’s proprietor, RaviKumar, in fabricating, installing, and commissioning the gasifiers. TERI alsotrained personnel from Nishant Architects in oven construction. The firstgasifier-based system made by 2M Industries was successfully installed andcommissioned by VEE/Nishant Architects in March 2000 at Vivek ColourFactory, a dyeing unit in Cubbonpet, Bangalore. Like many other dyeingunits in the Cubbonpet area, this unit had earlier been using diesel as fuel;therefore, the new gasifier system yielded considerable savings in fuel costs(Box 20).

Ravi Kumar, proprietor of VEE, soon realized that the gasifier-baseddyeing system could be successfully marketed only if adequate services wereoffered along with it as a package—an assured supply of wood chips ofappropriate size, technical advice, maintenance services, and the like. Hetherefore took steps to establish his own system to supply biomass of requi-site size to client units. With TERI’s help, VEE also established a reliable andwell-trained service and maintenance team. These measures paid off. ByDecember 2004, VEE had fabricated and installed 22 gasifier systems for silkdyeing units at Bangalore. At present, there are at least 40 gasifier-baseddyeing ovens operating in Cubbonpet alone.

A wood gasifier brings considerable savings in fuel costs when it replacespetroleum-based fuels in a dyeing unit. In comparison, the savings in fuelcosts are much smaller when a wood gasifier replaces the traditionalfuelwood-burning dyeing oven. This lesson was brought home when theproject organized a one-day workshop inthe Doddaballapura dyeing cluster. Thegasifier-based dyeing system was demon-strated at the workshop, and Ravi Kumarof VEE tried to market the system amongthe assembled entrepreneurs—but to noavail. The reason was simple: all thedyeing units in Doddaballapura operatedon traditional fuelwood ovens, and

A wood gasifier brings consider-able savings in fuel costs when it

replaces petroleum fuels…incomparison, savings in fuel costsare lower when a wood gasifierreplaces a traditional fuelwood-

burning oven.


Box 20A silk

dyer’s view

I own a small silk fabric-dyeing unitnamed Vivek Colour Factory. Our fam-ily occupation is silk fabric bleachingand dyeing of silk fabric. We are lo-cated along a small lane in theCubbonpet area of Bangalore, knownfor its silk dyeing activity and tradingin textiles. The factory is in fact asmall room annexed to my ownhouse. I depend on a daily job order,with a fixed unit rate applicable foreach silk service rendered. I collectthe raw fabric (saris) from localwholesale traders, agents, andretailers.

Traditionally, we used wood as themain fuel for burning in the ovensused for the dyeing and bleachingprocesses. But 15 years ago, I had toabandon the use of wood because ofsmoke, storage space problems, andcomplaints from neighbours/con-cerned authorities due to environ-mental pollution. Operating theseunits during the monsoon causedeven more problems due to non-avail-ability of wood; besides, wet wooddoes not burn efficiently. I found die-sel to be the only immediate substi-tute, though costly. On a typical day,during a dyeing operation of 10hours, I burned 36 litres of dieselcosting about 700 rupees. This was

almost 40% of the total processingcost. I was looking for help fromsomeone to reduce this heavy burdenof diesel cost.

Luckily, I came in contact withTERI, who suggested that I use theirgasifier for my day-to-day dyeing ap-plications. A trial demonstration wasshown to me at a unit nearby; mem-bers of other neighbouring units werealso present. I decided to install agasifier at my place for 60 000 ru-pees. On 19 March 2000, a gasifiersystem was installed by the local en-trepreneur with the help of TERI, andI and my colleague Venugopal quicklylearnt about its operations and main-tenance.

Today I am very happy with thegasifier performance. It saves me500 rupees every day. The process-ing is faster when compared to thetraditional wood oven. Now, there areno pollution complaints from theneighbours and the concerned au-thorities. By 30 April 2005 mygasifier had run for over 19 000hours, which added up to a fuel sav-ing of nearly 900 000 rupees over afour-year period!

R RajagopalVivek Colour Factory

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Into the field 109

switching to the gasifier system would have brought them only marginal fuelsavings. In contrast, most units in Cubbonpet had earlier switched fromwood to LDO (light diesel oil) as fuel—and switching from diesel to thegasifier system brought them substantial savings. This is precisely why mostof the replications have taken place in the Cubbonpet cluster. Table 6 illus-trates the economics of a typical dyeing unit when different fuels are used.

LARGE CARDAMOM CURING

As mentioned earlier, in 1996 TERI conducted studies of the traditional ovensor bhattis used to dry large cardamom at three selected sites in Sikkim. Thestudies revealed that the bhattis had very low energy efficiencies rangingfrom 5% to 15% (Table 7).

The studies clearly indicated the immense potential for increasing theenergy efficiency of bhattis by the use of biomass gasifiers. However, theyalso raised several questions and opened up a number of possibilities.

The energy efficiency of the traditional bhattis did not appear to be a bigissue with farmers for a simple reason: the farmers did not purchase anyfirewood for their bhattis. To fire a bhatti, labourers simply cut down a fewnearby trees. On the face of it, this practice of felling trees for burning inbhattis appears to have implications on deforestation; but a closer look re-veals that it may not! Large cardamom is a shade-loving plant and requirestree-cover for its growth. Thus, trees are planted whenever a new large

TABLE 6Operational economics of a typical dyeing unit processing

400 saris daily, using different fuels/ovens

Input Daily Daily Gross

cost input income daily

Operation Type of fuel/oven (Rs/sari) cost (Rs) (Rs) profit (Rs)

Bleaching Diesel oven 4.48 1790 3200 1410

Traditional wood oven 3.43 1371 3200 1829

Gasifier-based oven 3.17 1268 3200 1932

Dyeing Diesel oven 5.46 2184 4000 1816

Traditional wood oven 4.41 1765 4000 2235

Gasifier-based oven 4.16 1662 4000 2338


cardamom plantation is established or an existing one extended. Indeed,there are indications that the tree-cover of Sikkim has actually increased withthe spread of large cardamom cultivation. Hence, the argument that usinggasifiers would reduce deforestation by saving wood did not rest on strongground. However, the labour costs involved in cutting trees and the pollu-tion caused by wood-smoke were issues that merited consideration (Box 21).

Box 21Cloudless

view

Collecting baseline data on the tradi-tional bhatti at Ravangala meantstaying awake throughout the night.The first thing that struck me was thefact that there were so many morestars visible in the clear, unpollutedskies of Sikkim! It would be a pity, Ireflected, if such a clean environ-ment was affected by theparticulates, carbon monoxide, andother pollutants released from count-

less piles of burning wood. No onewas then aware of the so-called ABC(atmospheric brown cloud), a seriousenvironmental problem caused bywood/biomass burning. Now, I won-der how much the traditional bhattisin Sikkim have been contributing tothe ABC…

VVN KishoreTERI

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TABLE 7Study of three large cardamom units in

Sikkim in 1996: summary of data

Unit name/location

Measurement Mangan Naga Ravangala

Fresh capsules (kg) 747.0 507.5 580.0

Cured capsules (kg) 221.0 134.0 143.0

Fuelwood consumed (kg) 860.0 1149.0 464.0

Total drying time (hours) 35 40 26

Thermal efficiency (%) 10.8 5.4 15.5

Specific fuel consumption (kg fuel/kg fresh cardamom) 1.15 2.26 0.80

Into the field 111

As large cardamom curing is a labour-intensive activity in Sikkim, curing time ismore important than energy efficiency forfarmers as more time means more wagesfor labour. In general, important informa-tion on any drying process—total dryingtime, drying temperatures, different drying regimes, and so on—can beobtained from what are known as ‘drying rate curves’. However, there wereno data whatsoever on the drying characteristics of large cardamom. Asomewhat crude measurement in the field gave TERI some indications of thedrying rate, but more precise data were needed for developing a biomassgasifier suitable for drying large cardamom. TERI located a laboratory in thechemical engineering department of IIT, Mumbai that had a test-rig fordrying, and a small sub-contract was given to Prof. V G Rao to obtain therequired drying characteristics.17 These data—the first ever obtained for largecardamom—proved useful in the design of drying equipment, and alsoprovided clues as to how improvements could be made in the bhatti itself.

Any gasifier to be tried out in Sikkim had to meet certain criteria thatwere dictated by the socio-economic as well as geographical conditions inthe state. These criteria were enunciated clearly by A Tarnutzer, the SDCconsultant to ISPS, and they ran like a wish-list!� The gasifier had to operate without a blower, as many large cardamom

bhattis are located in remote locations where there is no electricity. (This,when nobody had ever operated a gasifier without a blower!)

� The gasifier should be transportable on the backs of human beings, as thisis sometimes the only means of transportation in Sikkim’s hilly terrain. (Agasifier made by any manufacturer would weigh at least a few hundredkilograms!)

� There were no big workshops in Sikkim, so the gasifier should be suffi-ciently ‘low-tech’, that is, relatively simple in design and easy to fabricate.At the same time, no compromise should be allowed on performance.

� Locally available materials should be used in the gasifier’s fabrication tothe maximum extent possible.

� The gasifier should cost as little as possible, preferably a few thousandrupees, because most Sikkim farmers are poor and cannot afford a costly

17 Rao V G, Mande S, Kishore V V N. 2001. Study of drying characteristics of large cardamom.Biomass and Bioenergy, 20(1): 37–43.

Curing time is more importantthan energy efficiency for large

cardamom farmers: longer curingtime means more wages for

labour


piece of equipment. (The smallest size commercial gasifier then availableunder the MNES schemes cost about 100 000 rupees.)

These criteria looked quite impossible to fulfil even for a hard-core appro-priate technology person! The ‘curing house’ concept used for drying smallcardamom in south India had been tried in Sikkim, but did not find accept-ance among farmers because it was too expensive (Box 22). Apart from thiseffort, no one seemed to be working in the area of improving the curingmethods (Box 23).

Box 22Partialcure

The ‘curing house’ concept is used todry small cardamom in south India. Inthis method, the fresh capsules arespread on wiremesh trays in a room.Firewood is burned in a furnace, andthe room air is heated indirectly bypassing flue gases through pipes laidin the room

In the 1980s, the Spices Board in-troduced improved curing houses ona trial basis for drying large carda-mom capsules in Sikkim (Figure 34).The curing houses were of three ca-pacities: 100 kg, 200 kg, and 800 kg(all weights relate to fresh capsules).By 1996, the Spices Board had in-stalled 20 curing houses of 100 kgcapacity, 152 units of 200 kg capac-ity, and one community-type unit of800 kg capacity. The curing houses

gave good-quality dried capsulescompared to the traditional bhatti,but the process was very slow. Be-sides, the curing houses were expen-sive: a 200 kg unit cost around 25000 rupees to set up. Also, farmersfound it very inconvenient to trans-port freshly harvested capsules fromthe fields to the curing house. Al-though no scientific assessment wasmade of the thermal performance ofthe Sikkim curing houses, in 1991TERI had conducted a study of similarcuring houses used in southern Indiafor small cardamom, and had shownthat they operated at very lowefficiencies of 3%–8%.18 All thesedisadvantages prevented the curinghouses from becoming popular inSikkim.

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18 TERI. 1991. Design, fabrication, testing, and field demonstration of energy efficient dryer forsome cash crops. Project report submitted to Department of Science and Technology, Government ofIndia.

Into the field 113

Figure 34Improved flue pipe curing house (Spices

Board design): (a) Schematic; (b) fieldinstallation in Sikkim

(b)

(a)


Developing the gasifier

Having considered all the above issues, TERI chose the tandoor as a model forits first prototype gasifier for curing large cardamom. The tandoor is a cook-ing oven used in northern India to make ‘rotis’. It is a simple furnace, madeby placing an earthen pot inside an empty oil drum or barrel. The spacebetween the pot and drum is filled with ash, stone chips, and other materialsthat provide insulation and also prevent the pot from cracking due to ther-mal expansion and contraction. The tandoor combines two advantages: it ischeap, and it does not require a blower as hot flue gases flow upward bynatural convection (Figure 35).

Box 23Dry

wisdom

After going through Tarnutzer’s seem-ingly ‘impossible’ list of conditions forproduct development, and realizingthat energy efficiency was a ‘non-is-sue’ for farmers, I was on the verge ofgiving up the idea of trying to developa gasifier for large cardamom curing.I thought I would get a little morewise on quality-related aspects bytalking to the local cardamom tradersin Sikkim. One of them said: ‘You mayget the cardamom dried perfectly, upto the desired low moisture content.But the ignorant farmer will pour wa-ter on the capsules after drying, to in-crease their weight! Of course, wecan always make out what the farmerhas done, and we offer him corre-spondingly lower rates for his pro-duce!’

I repeatedly asked the trader if hewould offer higher rates for betterquality, well-dried cardamom but hekept dodging the issue. Finally, Iasked him whether there was anyneed at all to improve the currentmethod of drying the capsules.‘Look,’ he replied, ‘I’ve been doing mybusiness of trading cardamom formany years. Nobody has ever comearound asking questions like you are!As for improving the way capsules aredried, you people should try it onlybecause nobody else seems to beworking in this area. Who knows?Maybe something will come out ofyour efforts!’

VVN KishoreTERI

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Into the field 115

Figure 35Laboratory testing for proof of concept: (a) use of tandoor

as gasifier; (b) modified tandoor as updraft gasifier;(c) schematic of experimental set-up

(b)(a)

(c)


Mark 0

Preliminary trials were undertaken at TERI’s Gual Pahari campus to examinewhether the tandoor could be used as an updraft wood gasifier. A small airinlet with a damper was provided at the bottom of the tandoor to supply acontrolled (and deliberately insufficient) quantity of air so as to achievegasification of the fuelwood. An arrangement was made to burn the pro-ducer gas at the top of the tandoor. Based on this lab prototype, a modifiedupdraft gasifier—Mark 0—was made from a used oil drum lined with‘supercrete’ insulating material in place of the earthen tandoor. Several trialruns were conducted to ensure that it produced enough gas and that theburning rate was sufficient. Thereafter, it was decided to test Mark 0 underactual field conditions. Besides providing performance data, the field testswould help in verifying the gasifier ’s capacity; that is, the tests would showwhether the gasifier was capable of drying a full batch of crop (400–600 kgfresh capsules) and how long it took to do so.

The harvesting season had already begun at the lower elevations inSikkim. The project team therefore set off from Delhi to Siliguri (the nearestrail-head for Sikkim), carrying with them the burner assembly as well as the‘supercrete’ insulation material for the gasifier. The idea was to fabricate theremaining parts of the gasifier at Siliguri and then carry them by road toSikkim.

However, at Siliguri the team was informed that fabrication work wouldtake four to five weeks—by which time the harvesting season would be overin Sikkim! Besides, the team was warned that the gasifier components werelikely to break while being transported to Gangtok, because the road was invery bad condition. Under the circumstances, the team had no alternative butto proceed directly to Gangtok and try to get the gasifier fabricated there.

At Gangtok, the project team held a meeting with ISPS and officials fromDoH (Department of Horticulture) to plan field activities. DoH is in chargeof the government’s programme to develop large cardamom activities inSikkim. A visit was made to Kabi village, about 18 km from Gangtok, and itwas decided that the gasifier should be tried out at Kachung Bhutia’s bhattias he was known to be a progressive farmer in the area.

To fabricate the gasifier, the team located a metal workshop at Gangtoknamed Gurung Traders. A used oil drum was purchased from an oil-vendingshop, and the gasifier’s many components such as GI sheet ducts, grates,etc., were fabricated by Gurung Traders under the TERI team’s supervision.All the items were then taken, along with the burner assembly and insulation

Into the field 117

material, to the field site at Kabi. At the site, the insulation material was castand fitted into the drum, and the gasifier assembled and installed in a pitinside the bhatti. The fuel charging door was modified at the site so as toenable removal of smoke and to allow quicker charging of fuel (Figure 36).Local labourers were hired on daily wages to supply firewood cut into pieces4–6 inches in length. The system was tested for performance in September1996 (Box 24).

Valuable feedback was received from farmers who witnessed the Mark 0trials. A few of their observations are listed below.� Placing the gasifier inside the bhatti exposed the cardamom capsules to

smoke, particularly during fuelwood charging, or when the gasifier wasbeing started and the flame was unstable.

� In order to charge fuelwood, the operator had to step inside the bhattiitself. This was a critical issue for the project team, as the producer gas

Box 24Clearing the smoke

of disbelief

In September 1996, TERI field-testedits first natural updraft gasifier sys-tem for large cardamom curing atKachung Bhutia’s farm at Kabi, innorthern Sikkim. Bhutia watched cu-riously as we started the gasifier. Likeother traditional farmers, he believedthat smoke was essential to dry largecardamom. When he saw the cleanflame of the gas burner below thecardamom bed, he laughed aloud.‘Without smoke, the capsules won’tdry!’ he said. He added that he wouldleave for Gangtok the following morn-ing to spend the weekend there. ‘I’llbe back on Monday; if God favoursyou, hopefully the cardamom wouldhave dried by then!’ he remarkedcaustically. Although we knew it was

heat, not smoke, that was requiredfor drying, his words did leave us feel-ing a little nervous.

We operated the gasifier throughthe night. The next morning Bhutialooked in just before leaving forGangtok. He was stunned to see thecardamom capsules in the laststages of curing. All of them had re-tained their natural reddish colour:he broke open several to ensure thatthe insides were completely dry aswell. So delighted was he that hepostponed his Gangtok trip andstayed on till the curing was com-pleted.

Sanjay MandeTERI

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Figure 36Trial field-testing of Mark 0 at Kabi, North Sikkim:

(a) gasifier in operation; (b) modified fuel charging doorenabling smoke removal and quick fuel charging

(b)(a)

contained carbon monoxide which posed a far more serious threat to theoperator than smoke.

� Mark 0 required fuelwood charging every two or three hours, whichmeant monitoring the gasifier and bhatti throughout the night. Farmerswere reluctant to do this.

� Mark 0 was very bulky; it weighed over 150 kg, making it difficult totransport.

Mark 1

Based on the farmers’ feedback, TERI developed an improved version of thegasifier—Mark 1 (Box 25). The most important change was to place thegasifier outside the bhatti. The producer gas flowed by natural convection tothe burner, which was placed below the cardamom bed in the bhatti(Figure 37). This new arrangement kept smoke from the gasifier away fromthe cardamom bed, and allowed the capsules to retain their natural hue.

Separating the gasifier unit from the bhatti structure had anothergreat advantage: it allowed modifications to be made in the fuelwood

Into the field 119

Box 25The human angle: lessons in

participatory development

Working with the large cardamomfarmers in Sikkim was a great learn-ing experience for all of us in theproject team. We realized the impor-tance of seeing things from the farm-ers’ point of view; of empathizing withthem; of listening to their opinionswith patience and understanding…It was easy for us to tell farmers thatthe gasifer had to be charged withfresh fuelwood every two hours. Afterall, we ourselves did it when westayed awake the whole night togather data on the drying process.But then, we had to do it only for afew nights, and that too in shifts! Toexpect farmers to do it throughoutthe season, to stay awake night afternight, was something else. The solu-tion: we increased the size of thegasifier’s hopper in the Mark 2 ver-sion so that it held enough fuelwoodto last 6–7 hours. This allowed thefarmers enough time to sleep.We also learned that ‘user needs’ area mesh of extremely complex andsubtle factors. Often, a technologicalmeasure that addresses one needmay unexpectedly impinge uponother needs. For instance, thegasifier had an insulation layer thatcut down heat loss and thereby in-creased energy efficiency. But thefarmers were not happy with this.They missed the traditional bhatti

with its open hearth and burninglogs, in front of which they could sitand warm themselves during the coldNovember nights! Indeed, one farmerfound an ingenious way to keep him-self warm even with the gasifier (thiswas the Mark 0 version, when thegasifier was placed within the bhatti).He dug a shallow trench inside thebhatti’s hearth, right next to thegasifier, and lay down in it! Thiscaused a great deal of consternationin the team. We warned him that hecould be poisoned by carbon monox-ide in that enclosed space in case theflame was suddenly extinguished bya shower or a gust of wind. In Mark 1and later versions the gasifier wasplaced outside the bhatti, reducingthe danger…Similarly, we tried out an inclined lidin the Mark 1 version of the gasifier(instead of the flat lid used in earlierversions). But farmers were unhappywith this modification. They had beenusing the flat lid as a kind of ‘hotplate’ on which to keep their cups oftea or liquor warm during their cold,night-long vigils; this was just not pos-sible with an inclined lid. We there-fore went back to the flat-lid design!

Sanjay MandeTERI

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Figure 37Mark 1 prototype for extended field-testing: (a) schematic;

(b) field testing at Assam Lingzay

(b)

Figure 38Schematic diagram of modified

top cover with fuel-charginglever mechanism

charging system. Mark 0’s smallcharging door was replaced by alarger (30 cm × 30 cm) square doorthat could be opened and shut bymeans of a simple lever mechanism.When the door was opened it tookthe shape of a hopper, allowing easyfeeding of fuelwood (Figure 38).Mark 1’s larger door also allowedlarger pieces of fuelwood (25–30 cm)to be fed to the gasifier.

A major problem with Mark 0 wasits sheer weight (over 150 kg), whichmade it extremely difficult to carryaround on rugged hill tracks. Theproject team solved the problem tosome extent by modifying the insula-tion layer in the gasifier so that itcould be carried in two separatesections (Box 26). To improve thequality of flame, various types of

(a)

Into the field 121

Box 26Weighty issue

Mark 0’s great weight was to a largeextent due to the high-temperatureinsulation material used for thegasifier. This insulation had beendone in situ, and as a result the en-tire insulation material became an in-tegral part of the gasifier (oil barrel),making it heavy as well as bulky.

To make the gasifier more portableyet provide adequate heat insulation,several grades of castable insulationwere tried out. Finally, the projectteam chose ordinary-grade ‘firecrete’material. This new insulation was

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made in the form of two castablerings of one-inch (2.5 cm) thickness,which could be carried separately(Figure 39). Although the overallweight of the gasifier did not comedown very much, the detachable in-sulation rings made the systemeasier to carry around. Also, in com-parison to Mark 0’s high-temperatureinsulation material which cost 21 ru-pees/kg, Mark 1’s firecrete insula-tion cost only 9 rupees/kg. Thus, thismeasure reduced the cost of insulat-ing the gasifier by over 50%.

Figure 39Improving the gasifier insulation:

(a) Individual castable insulation ring lightenough to allow transportation in Sikkim’s

rugged terrain; (b) Insulation rings withgradually reducing thickness from bottom

to top

(a)

(b)


burners were tried out. Finally, a square burner with multiple ports wasselected and incorporated into the system.

The project decided to field-test Mark 1 in all the four districts of Sikkim.Accordingly, the gasifier system was tested at Assam Lingzay (East Sikkim),Kaluk (West Sikkim), Ravangala (South Sikkim), and Mangan (NorthSikkim). In all, 27 batches of cardamom were dried using the gasifier systemand over three tonnes of improved quality large cardamom were produced.Out of the four testing sites, two were located in remote areas without roadaccess. This showed that Mark 1 could be shifted across rough terrain with-out too much difficulty.

The results of the Mark 1 field-tests are summarized below.� The gasifier system gave improved thermal performance, with fuel sav-

ings of over 60%.� The dried capsules were of visibly better quality, as they retained their

natural reddish hue.� The capsules also retained over 35% more volatile oils, without any burnt

smell.

The Mark 1 field-tests also provided further feedback from users andgovernment officials. Indeed, to one of the officials the gasifier appeared asnothing short of a miracle (Box 27).

Box 27Magicalflame

In 1997, we demonstrated an im-proved gasifier model—Mark 1—at theAssam Lingzay testing site in EastSikkim. In this model, the gasifier it-self was placed outside the bhatti;the producer gas was piped back intothe furnace and burned. In effect,wood was being ignited at one place,but the flame was created elsewhere.An official of the Department of Horti-

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culture was so amazed at seeing the‘detached’ flame that he literallycharged about, calling out to every-one to come and witness the ‘mira-cle’. Indeed, in subsequent visits, theproject staff were referred to asjaadugar (magicians)…

Sanjay MandeTERI

Into the field 123

Mark 2

The feedback from farmers on the Mark 1 gasifier system helped the projectto evolve an improved, user-friendlier version named Mark 2 (Figures 40, 41,42, and 43). Some drawbacks in Mark 1, and the measures taken to rectifythem in Mark 2, are briefly described below.

It was decided to try out the Mark 2 system in various parts of Sikkim ona pilot scale. The project team requested the Horticulture Officer of NorthSikkim to prepare, in advance, a list of farmers in the Mangan region whowere willing to participate in the pilot-scale tests of Mark 2 during the 1998harvesting season. A total of 17 farmers expressed their willingness to

Drawback in Mark 1

Fuel-charging door experiencedleakage of gas.

Fuel had to be re-charged twiceduring the night, when the systemwas run round-the-clock, or elsethe entire fuelwood stock was de-pleted and the gasifier had to berestarted.

‘Ceramic blanket’ insulation ma-terial was used to shield the gas-carrying duct. But this materialwas not easily available locally.

Single burner at the centre did notgive uniform heating, particularlyin the corners

Improvements made in Mark 2

Water seal provided in fuel-chargingdoor to make it leakproof.

The fuelwood storage capacity was in-creased by adding an extra bin—anopen-ended empty barrel added on topof the gasifier. With this, fuelwood hadto be recharged only at intervals of sixto seven hours.

The project team conducted experi-ments with locally available materialsto develop an alternative insulationmaterial, and a replacement wasfound. A thin layer of mud was first ap-plied to the gas duct. This was thenwrapped in a layer of sarkhanda—acane-like material obtained from a lo-cal plant (Saccrum munja). Finally, thesarkhanda was coated with a second,thicker layer of mud.

Multiple burner system (comprisingone central and four corner burners)provided for better distribution of heat.


Figure 40Improving the fuel charging door: (a) schematic describing

operational inconveniences pointed out by farmers;(b) schematic of water seal in fuel charging door

(b)

(a)

Into the field 125

Figure 41Mark 2 gasifier system: (a) field installation;

(b) schematic diagram; (c) exploded view

(c)

(a)

(b)


Figure 42Use of bamboo mat with mud layers

as duct insulating material

Figure 43Multiple burner for uniform

heating of entire cardamom bed

Into the field 127

participate in the exercise. They informed the project about their probableharvesting time, the quantity of crop they expected, and the availability offuelwood for the trials. To ensure smooth tests at all the sites, the projectentered into a formal agreement with each of the farmers (with DoH officialswitnessing the agreement). The salient features of the agreement are listedbelow.� TERI would supply one gasifier system to couple to the existing bhatti.

The entire system’s cost (including the cost of transporting it to Mangan)would be borne by TERI.

� TERI would train local hands in installing and operating the system at acentralized training session to be organized at one of the test sites.

� TERI would provide technical backup to the farmer during operations,and TERI’s technicians would be available at Mangan for troubleshootingthroughout the harvesting season.

� The farmer would ensure sufficient supply of firewood (250–300 kg perbatch of 400 kg fresh capsules); the firewood would be cut into pieces 8–9inches long. The firewood would be kept ready in advance.

� The farmer would provide manpower to (a) shift the gasifier to the bhatti;(b) modify the bhatti as needed and install the gasifier; and (c) operate thesystem. He would also provide other infrastructure, including a roof overthe bhatti.

Finding a local manufacturer

There was very little time left before the start of the 1998 harvesting season.The project therefore sought a local manufacturer who could make thegasifier in large numbers quickly, yet according to specified standards. Theteam identified Figu Engineering Works, Ranipool (East Sikkim) for thepurpose. The firm’s proprietor, Jaganarayan Sharma, was a self-taught entre-preneur with over a decade’s experience in all kinds of metal fabricationwork—gates, grain storage bins, trunks and boxes, automobile components,and so on. More important, Sharma was familiar with the large cardamomsector. Earlier, the Sikkim office of the Spices Board had selected Figu Engi-neering Works to fabricate the curing houses for large cardamom (similar tothose used by small cardamom farmers in south India) that were tried outwithout success in Sikkim. In the process, Sharma had gained considerableknowledge about large cardamom cultivation and curing, including issuesrelated to the quality of capsules, labour, and markets.

Extensive training was given by TERI to Sharma and his staff to fabricatethe many components of the Mark 2 gasifier. First, one model was fabricated


under close supervision of TERI’s technicians. This gave the firm enoughexperience and confidence to fabricate the remaining systems on its own.However, TERI’s technicians remained on hand to provide guidance andsupport as and when required. This ensured that the systems were manufac-tured correctly and met the high standards of accuracy and quality needed toperform well in the field (Figure 44).

Figure 44Fabrication of gasifier system components:

(a) castable insulation rings; (b) MS connecting pieces;(c) MS grate; (d) producer gas multiple burner

(b)(a)

(c) (d)

Into the field 129

The system proves its mettle

In the 1998 season, 15 pilot-scale Mark 2 systems were commissioned suc-cessfully at various test sites in North Sikkim. The cost of the systems wasshared equally between ISPS and DoH. Among the farmers who used thesystem, some managed to sell their improved-quality cardamom in the localmarkets at a considerable premium over the prevailing prices: 10%–25%higher, or in some cases even more (Box 28). During this period, a delegationfrom the Ministry of Agriculture, Kingdom of Bhutan visited the Assam

Box 28Testingtimes

In 1998, TERI’s Mark 2 gasifier sys-tem was tested at a farm in Mangan,Sikkim. The farm belonged to P GTenzing. He led us on foot, deep intothe farm, till we came upon a steepslope next to a stream. Here he pro-ceeded to pitch a tent. Only then didwe realize the tough days that layahead. For a week we lived in thattent. It was indeed a remote place.One day we developed fever. Para-cetamol tablets were sent for, but ar-rived after we had recovered!

However, Tenzing was probablyonly testing our sincerity and dedica-tion, for the very first morning heturned up at our tent with all his fam-ily members. Indeed, he and his wifemade it a point to visit us almostdaily. Often, they brought home-madesnacks for us. His mother was so im-pressed by our presence there thatshe scolded her grandson: ‘See!These people have come all the wayfrom far-off Delhi to stay in yourfarm…while you young people neverbother about it! You don’t know how

much wealth you have inherited fromyour forefathers!’ She even made it apoint to attend the workshop held inApril 1999. Here, she criticized thegovernment for its inaction in helpinglarge cardamom farmers, and de-clared that TERI was the only institu-tion that had come to their aid.

During our stay at Tenzing’s farmwe successfully commissioned andran the Mark 2 gasifier. The Tenzingswere so impressed by its perform-ance that, with TERI’s assistance,they later constructed a secondgasifier system. Now, their farm sellshigh-quality reddish-coloured driedcardamom under the name TenzingPlantation Quality Cardamom. At onepoint their cardamom fetched 400 ru-pees per kilogram (1998 prices)—against the then prevailing wholesalemarket price of 60–80 rupees perkilogram for traditionally cured carda-mom.

Sanjay MandeTERI

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Lingzay site and saw Mark 2 in action. So impressed were the delegates thatthey immediately picked up four systems from Figu Engineering Works andtook them back to Bhutan for trials at the RNR–RC (Renewable NaturalResources—Research Centre), Jakar.

Tests showed that Mark 2 enabled fuelwood savings of over 60%. It alsogreatly improved the quality of product (Figure 45). The controlled and cleanburning of the producer gas helped preserve the natural reddish-brown hueof the large cardamom capsules, and retained 35% more volatile oils in thecapsules along with their pleasant aroma. The drying time was reduced to20–24 hours, which meant that more capsules could be dried within a givenperiod. Besides wood-chips, Mark 2 was designed to burn prunings as well.The system thus offered great potential to reduce the overall felling of treesfor fuelwood. The cost of the Mark 2 gasifier was around 10 000 rupees,which made it affordable to the average large cardamom farmer. The pay-back on investment was estimated at less than one year (Figure 46).

Figure 45Mark 2 system’s field

performance in Sikkim

Into the field 131

Figure 46Advantages of gasifier system

over traditional bhatti


Project review workshop

On 27 April 1999, TERI organized a project review workshop at Gangtok todiscuss the experiences of the farmers during the Mark 2 pilot-scale tests inthe Mangan region, and to evolve a plan to popularize the gasifier systemafter improving it based on the farmers’ feedback. Among the participantswere representatives from ISPS, the Spices Board, officials from severalSikkim government departments, financial institutions, and farmers andlarge cardamom traders (Figure 47).

Figure 47Project review

workshop at Gangtok

The farmersmade the followingpoints.� Mark 2 saved

labour costs, asless fuelwoodwas consumedby the gasifier,which meant lesswages had to bepaid to labourersto fell trees.Also, it waseasier to monitorthe fire with thegasifier systemthan in thetraditional bhatti.

� The quality oflarge cardamomproduced by using Mark 2 was very good. In fact, the capsules were freefrom fungal attack even after several months.

� Difficulties were faced in transporting the gasifier’s insulation rings; quiteoften, the rings broke while being carried from place to place. The replace-ment of the rings was a problem.

Some farmers remarked that it might be difficult to obtain dry woodpieces to feed the gasifier, especially during the rainy season. The TERI teampointed out that it was a routine practice among farmers to collect and storefuelwood in their houses during the dry months for domestic use in winter

Into the field 133

and during the rainy season. Hence, it should not be a problem for the farm-ers to use some of their stored dry wood for the gasifiers.

Following the workshop, TERI submitted a proposal to ISPS for initiatinga plan to commercialize the gasifier system by finding and building linkagesbetween suitable players such as manufacturers, marketers, and financiers.However, DoH was keen to launch a widespread demonstration programme,similar to the one in Mangan, in the remaining three districts of Sikkim. Asthe 1999 harvesting season was fast approaching, it was decided that TERIshould go along with DoH’s plan and assist in the proposed demonstrations.The informal understanding between TERI and DoH was that after thedemonstrations, and once TERI developed a final, commercial version of thegasifier system, DoH would promote the system across the state under itssubsidy schemes.

Transfer of know-how

To enable DoH officers and field staff to demonstrate and popularize thegasifier system among large cardamom farmers in East, West, and SouthSikkim, it was first necessary to train them in the many aspects of the newtechnology. TERI organized a centralized training programme for DoHpersonnel at Gangtok in August 1999. DoH was asked to identify its key fieldstaff in the East, West, and South districts of Sikkim to attend the trainingprogramme. The main objective was to transfer the know-how of the Mark 2system to DoH—including details of its fabrication, installation, and mainte-nance; training of farmers in its use; and troubleshooting.

Accordingly, DoH selected 15 field personnel to undergo the trainingprogramme, which was divided into the following sections.� Overview of the large cardamom industry in Sikkim in the local, national,

and global context, with an emphasis on the need for better technology toimprove the quality of capsules as well as to protect the environment.

� Study of the traditional bhatti.� Introduction to biomass gasification technology and its benefits.� Step-by-step development of the gasifier system for large cardamom

curing.� Installation and operation of the gasifier system in the field.� Maintenance and troubleshooting.

Small-scale models were used to explain the principles of the gasifiersystem, and posters and manuals were distributed among the participants.


The manuals contained detailed sketches that showed, step by step, how toassemble and install the gasifier in the field. Not only were the manualsuseful for the DoH staff, they were designed so as to be easily comprehensi-ble to farmers who did not possess reading skills. The DoH staff and farmerswere trained on the system at one selected site in each district (Figure 48).

Each of the 15 participants from DoH was given the responsibility toinstall and demonstrate two gasifier systems in his area. For this purpose, 30gasifier systems were fabricated by Figu Engineering Works, with DoH andISPS sharing the systems’ cost. DoH field personnel demonstrated 10 systemseach in the East, West, and South districts of Sikkim. These demonstrationshelped popularize the gasifier technology for large cardamom curing. Theyalso helped acquire further feedback and advice from farmers on the gasifiersystem. This information helped TERI fine-tune the design of Mark 2 to makea commercial version of the gasifier.

Scientist–user interface

Towards the end of the harvesting season in 1999, a scientist–user interactionmeeting was organized by TERI at Lower Pelling—one of the 10 field-testingsites in West Sikkim. The purpose was to give scientists, project staff, and

Figure 48 (a)Training of DoH staff and farmers for transfer of

know-how: small-scale models used for self-learning

Into the field 135

Figure 48 (b)Training of DoH staff and farmers for transfer

of know-how: sample pages of manuals

Figure 48 (c)Training of DoH staff and farmers for transfer of

know-how: on-system training in the field


large cardamom farmers an opportunity to exchange views and ideas aboutthe entire biomass gasifier initiative in Sikkim. Among those who attendedwere Dr Rudolf Dannecker, Counsellor and Head, SDC New Delhi; Dr UdoHoeggel, visiting Senior Advisor, ISPS; professionals from TERI; the 30farmers who had participated in the 1999 demonstration programme; andDoH officers and field staff from all four districts of Sikkim. TERI arranged afield-testing of the gasifier system and exhibited posters that described itsfeatures and benefits (Figure 49). The majority of farmers felt that DoHshould continue with its 100% subsidy of the system’s cost. However, a fewsuggested that the subsidy could gradually be reduced as more systems wereplaced in the field and farmers became confident in its use.

Figure 49Interaction meet at Lower Pelling: (a) Dr Udo Hoeggel

of ISPS initiating discussions; (b) Dr Rudolf Danneckerof SDC, Delhi interacts with farmers.

(a)

(b)

Into the field 137

Test marketing ofimproved-qualitycardamom

TERI carried out twostudies to assess theextent and nature of themarkets—domestic andexport—for the im-proved-quality largecardamom produced bythe Mark 1 gasifiersystem in the 1997 sea-son. One study was aconsumer survey inDelhi, and the other wasa detailed market analy-sis of the major tradingcentres in the product,namely, Delhi, Kanpur,Amritsar, Lucknow, andJaipur.

Consumer survey

It was important to knowwhat the actual end-users (that is, householdconsumers) felt about theimproved quality oflarge cardamom dried by

Figure 50Hindi questionnaire to assess

consumers’ response to gasifier-cured large cardamom

gasifier-based bhattis. To this end, TERI commissioned a survey of house-holds in Delhi by Shambhavi Marketing Agency. A comprehensive question-naire in Hindi was developed (Figure 50) and a door-to-door survey wasconducted in 1020 houses in Delhi. The questionnaire was designed to gatherinformation on two major issues regarding large cardamom:� what constituted ‘good quality’ in the minds of consumers;� feedback from consumers regarding the quality of capsules dried by

gasifier-based bhattis, as compared to capsules dried in traditional bhattis.


Sample packets of improved-quality large cardamom (that is, capsulesdried by gasifier-based bhattis) were handed out to consumers. They wereasked to try out the product, and give their responses by comparing it withthe traditional cardamom available in the market. The responses were en-couraging. Over 70% of the users felt that the gasifier-dried cardamom wassuperior in colour/appearance, and over 53% felt it tasted better too. Theoverall opinion was that the gasifier-dried cardamom was superior in qualityand would fetch a premium price in the market (Figure 51).

Figure 51Responses to consumer survey: (a) users’preferred quality parameters; (b) feedback

on quality of gasifier-cured capsules

(a)

(b)

Note Figures in brackets denote number of respondents

Into the field 139

Market analysis

TERI conducted a market analysis by gathering data from traders in fivecities—Delhi, Kanpur, Amritsar, Lucknow, and Jaipur—through detailedquestionnaires, surveys, and by direct interviews. Samples of large carda-mom dried by the gasifier system were handed out, and the responses ofmerchants and consumers recorded and analysed. The results were againvery positive: the majority of respondents in all the cities felt that thegasifier-dried large cardamom was distinctly superior in taste, appearance,and quality. They felt that it would fetch a 10%–15% premium in the markets,provided the product was available in bulk quantity and in consistently goodquality. This of course would be possible only if and when the gasifier sys-tem was promoted and used on a wide scale by large cardamom farmers.

A similar market analysis was conducted for cardamom oil extracted fromthe gasifier-dried large cardamom capsules. Here, too, the response of per-fume manufacturers, flavouring agent suppliers, and others was very posi-tive. The oil was tested for its quality at the Central Food TechnologyResearch Institute, Mysore; the Shriram Institute for Industrial Research,Delhi; and in TERI’s in-house laboratory. The tests established that the oilwas of superior quality compared to that extracted from traditionally driedcapsules.

Training and awareness generation

As mentioned earlier, in August 1999 TERI organized a centralized trainingcourse in Gangtok for a number of DoH field personnel from the East, West,and South districts of Sikkim in the installation and operation of the gasifiersystem. To supplement its efforts to spread awareness about the new technol-ogy and to assist in its adoption by farmers, TERI technicians gave extensiveon-site training as well to the field staff of DoH in all the districts of Sikkim.The training covered every aspect of the gasifier system: step-by-step meth-odology to install the gasifier; ways to improve its performance; preparationof dry cut-wood; start-up and shutdown procedures; operation and mainte-nance; and troubleshooting. TERI prepared a series of detailed users’ manu-als to support its training efforts.

Many large cardamom farmers are located in the remote areas of Sikkim.To make them aware of the new gasifier technology and its benefits, TERIprepared and distributed several brochures, leaflets, and posters that madeliberal use of colourful illustrations and catchy slogans. These brochures


were designed around a variety of themes. The idea was that various players,ranging from the forest department to marketing agencies, could use them topromote the concept of gasifier technology in different ways (Figure 52). Forinstance, the forest department could use the posters that highlighted thethreat of deforestation and pollution due to the excessive use of traditionalbhattis, and how this threat could be countered by the use of the gasifiersystem for curing large cardamom. Similarly, a manufacturer or marketingagency could use posters describing the simplicity and portability of thegasifier system and how it was ideally suited for use by large cardamomgrowers in hilly regions.

ISPS arranged for the broadcast of programmes on the gasifier system andits benefits by All-India Radio, Gangtok (Figure 53). The programmes in-cluded interviews with farmers, DoH officials, and experts from ISPS andTERI. A spur-of-the-moment idea led to a video recording being made of thesystem during its demonstration at a large cardamom plantation. The localcable TV network subsequently aired the video (Box 29).

Box 29A well-scored

goal!

Among other sites, the Mark 2gasifier system was demonstrated inKarma Bhutia’s farm. The local cableTV operator, a friend of Bhutia’s, wasamong those who had gathered towitness the demonstration. He had asudden, wonderful idea—he wouldrecord the entire proceedings andbeam it during ‘prime time’ acrossthe cable network (along with a suit-able commentary in the local lan-guage). Sikkim being a football-lovingstate, he knew prime time would havemost people glued to the sportschannel watching their favourite foot-ball star—the famous BaichungBhutia—in action.

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And so it was that later that day, in-stead of the usual commercials dur-ing breaks in their live football game,TV viewers saw the Mark 2 large car-damom dryer in action, learnedabout its assembly and maintenance,and obtained valuable insights intothe benefits the system offered. Theimpact was discernible in the daysthat followed: several farmers whomwe were training showed noticeableadeptness at picking up the tech-niques of assembling and operatingthe gasifier. ‘We saw it all on the TV,we know how to do it!’ they cheerfullytold us.

Sanjay Mande, Lal BabuTERI

Into the field 141

Figure 52Theme-based brochures prepared to spread awarenessabout the benefits of gasifier-based curing technology


Figure 53Recording of

interviews, and ofgasifier installation

and operationprocedures, forbroadcast by SCCable and AIR

Gangtok

Developing a commercial version

Technically, Mark 2 had proved its mettle.However, there was still scope for improvingthe gasifier system by making modificationsand adding features that would make it accept-able on a large scale. In other words, with Mark2 the technology had ‘matured’, but fine-tuningwas needed to make a marketable version ofthe gasifier system.

As described earlier, 30 Mark 2 systems weremade in 1999 and sent to various sites in East,West, and South Sikkim for demonstration andtrials. Based on feedback from farmers whooperated the systems, measures were taken tomake the Mark 2 system user-friendlier. A fewof these are described below.� Farmers reported that the castable insulation

rings tended to break while being trans-ported across the rugged terrain in theinterior areas of Sikkim. Replacement of therings was difficult, because the material wasnot available locally. To seek expert advice inthe matter, in November 2001 a TERI teamvisited the ACC Research and ConsultancyDirectorate, Thane (Maharashtra)—a majormanufacturer of castable insulation materi-als, including the variety used in the Mark 2system. Based on its interactions with thefirm’s officials, the TERI team developedand successfully tested a reinforced versionof the insulation ring.

� TERI also developed insulation rings madefrom RCC (reinforced cement concrete)—amaterial that was readily available in Sikkimitself, from a ‘Hume’ pipe manufacturerlocated near Rangpo.

� The material to make the main gasifier andfuel hopper was changed, from used oil

Into the field 143

barrels to MS sheet metal. Not only did this improve the fabricationquality and extend the life of the gasifier system, it also greatly improvedits appearance and made it more appealing to farmers.

� A large number of user-friendly features were incorporated in the fine-tuned model. With valuable inputs from Mohan Kulkarni of 2M Indus-tries, Mumbai, the gasifier system was designed in the form of modulesthat were easy to assemble and dismantle, and hence easier to carryaround across difficult terrain. Components were modified to improvetheir durability and appearance, joints were strengthened and made leak-proof, and so on. Great attention was paid to detail. For instance, theearlier Mark 2 version had a small plug-and-socket arrangement to ensurestoppage of air supply when the gasifier was shut down. The project teamdecided to attach the plug to the socket with a chain in the improvedversion, so that the plug would not fall off and get lost during field trialsor while being carted along hilly paths! Similarly, in its earlier version thegasifier’s top cover had a metal handle that was used to lift the coverduring fuelwood charging. This metal handle became very hot while thegasifier was in operation. Hence, the project replaced the metal handlewith a wooden handle to allow safe and easy lifting of the cover(Figure 54).

By late-2001, TERI was ready with the fine-tuned, commercial version ofMark 2. Extensive publicity campaigns and widespread demonstrations ofthe earlier version of Mark 2 had helped make farmers across Sikkim awareof the new technology and the benefits it offered. In fact, farmers had di-rectly placed orders for five gasifier systems from Figu Engineering Works.The time was indeed ripe to promote the commercial version of the system.

One step forward, two steps back

Unfortunately, at this critical juncture DoH arranged for the fabrication of100 gasifier systems based on the earlier Mark 2 design—with all its identi-fied drawbacks—even though an improved model had already been de-signed by TERI! Nor did DoH inform TERI while taking this unexpectedstep. The most charitable explanation for DoH’s action is that the departmentwas overanxious to promote the gasifier system. However, this argument isbelied by the fact that DoH did not order the 100 systems from Figu Engi-neering Works—the firm which had been involved with system developmentfrom the start, and whose personnel had been intensively trained by TERI in


Figure 54Improved updraft gasifier prototype developed forlarge-scale promotion: (a) side view showing gas

outlet; (b) front view showing air inlet

(a) (b)

making the gasifier systems. Instead, DoH ordered the systems from a com-pletely unknown fabricator based in Siliguri (West Bengal). The systems weresupplied to large cardamom farmers across the state under heavy subsidy,that is, virtually free of cost. Technically, the systems performed reasonablywell in the field, but they lacked all the improved features that had beenpainstakingly developed by TERI and built into the fine-tuned, marketableversion of Mark 2. In effect, an imperfect product was launched by DoH intothe field on a large scale even though an improved product had been devel-oped by TERI after extensive research, trials, and interactions with farmers.Thereafter, further initiatives by TERI to take the process forward met with alukewarm response from both DoH and ISPS.

Into the field 145

In a sense, the gasifier system for large cardamom curing in Sikkim metwith the same fate as the gasifier system for cocoon cooking/silk reelingdeveloped in Ramanagaram. It is interesting to compare the two cases. Bothsystems were developed step by step and in a largely participatory manner.Both systems delivered considerable fuel savings and improvement in thequality of the product. In both cases, the project made efforts to involve therelevant government departments (DoS and DoH) in promoting the systems.In both cases the project’s efforts did not yield the desired results. However,the reasons were entirely different in the two cases!

In the absence of financial assistance by way of loans from banks, theRamanagaram gasifier system’s cost (65 000 rupees) made it expensive forthe average silk reeler. On the other hand, DoS was never interested in promot-ing the gasifier system under its subsidy schemes. The project tried to lay thegroundwork for reelers to obtain financial assistance from banks, but foundthat banks wanted DoS to certify the gasifier system’s performance. Theproject made efforts to get this certification from DoS, only to be thwarted bya wall of official apathy. As a result, the Ramanagaram system did not replicate.

The Sikkim gasifier system’s cost (10 000 rupees) was low enough to makeit affordable to the average large cardamom farmer. From the very outsetDoH, Sikkim (unlike DoS in Karnataka) expressed keen interest in promotingthe system under its subsidy schemes. The project therefore worked closelywith DoH in demonstrating the system all across the state. DoH field person-nel in all the districts were trained to assemble, install, and operate thesystem. The unwritten understanding between the project and DoH was thatonce the project developed a final, commercial model, DoH would promote itat subsidized cost. Yet, DoH jumped the gun for reasons still unclear andlaunched 100 imperfect systems into the field without taking the project intoconfidence. As a result, the Sikkim gasifier system too did not replicate in themanner hoped for (Box 30).

So far, around 150 gasifier systems have been installed in Sikkim. Asmentioned earlier, four Mark I gasifiers were picked up by the Ministry ofAgriculture in Bhutan for demonstration. One system was procured byTribhuvan University, Kathmandu (Nepal) for comparative tests against thetraditional curing system used in that country; the gasifier system reportedlyperformed very well. Another 25 systems were procured by NEPED(Nagaland Empowerment of People through Economic Development), aproject supported by the India–Canada Environment Facility and working inthe field of agro-forestry. In 2005–06, a further 10 systems were ordered fromFigu Engineering Works by NEPED.


Box 30Small may be beautiful…but

big support needed

Some of the ‘perceived’ drawbacks ofthe silk reeling gasifier system—highinitial cost, electricity needed for theblower, and the need to cut fuelwoodinto small pieces—were absent forthe cardamom curing gasifier. Its ini-tial cost was just about 10 000 ru-pees; a blower was not needed eitherfor starting or for sustained opera-tion; and large pieces of wood couldbe charged into the gasifier. In addi-tion, there was enthusiasm and sup-port from the government of Sikkim,unlike the case of the Karnataka bu-reaucracy which preferred ‘watchingthe developments’ in the project’s ef-forts to promote the silk reelinggasifier system.

Yet, the cardamom curing gasifierdid not move, leave alone take off.Our observations, over the last dec-ade or so of trying to upscale andmainstream gasifier systems, sug-gest that these systems require var-ied and sustained marketingstrategies which of course have to bebacked by financial support. Or else,there should be strong commercialinterests where there is money to bemade by ‘everyone’ concerned.

We were naïve to believe that if aproduct/technology is strong, it will

sell like hot cakes. We now know thateven in the case of hot cakes, some-body has to sell them. Just who that‘somebody’ is, or how that person orentity would keep selling the product,are questions that cannot beanswered easily—especially when thebuyer happens to be the small farmeror the marginal silk reeler, and notthe relatively cash-rich urban con-sumer.

The haste with which a hundredcardamom curing gasifiers were in-stalled without quality control byDoH, the reasons for that haste, andthe resistance in later years to any ef-forts for further dialogue can all prob-ably be explained and analysedtoday; but it seems to have been aclear case of lost opportunity…

Yet, maybe not entirely lost! Thenatural draft gasifier found other ap-plications in due course—green brickdrying in Kerala, cooking for school-children in Orissa, improved boiler forbamboo mat-making, and gasifier forthe Italian oven in Siddlaghatta (witha small blower added for the latterapplications to increase thermalpower output).

VVN KishoreTERI

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Into the field 147

APPL ICAT IONS : THE L ARGER WEB

The project’s activities among SMiEs in the silk and large cardamom sub-sectors covered a span of over 10 years. During this period, the team mem-bers acquired considerable experience and confidence in studying andanalysing the complex energy processes that took place in these SMiEs, andin designing and developing both downdraft and updraft gasifiers to in-crease thermal efficiency, output, and quality of product.

The gasifier systems developed for silk reeling and large cardamomcuring did not replicate to the desired extent for a variety of reasons, asdescribed earlier. Yet, the presence of team members in the field for extendedperiods of time, and their interactions with entrepreneurs, manufacturers,government officials, NGOs, and others helped in creating and spreadingawareness about the potential benefits offered by biomass gasification tech-nology in all kinds of SMiE applications.

The results became visible in the form of a large number of ‘offshoot’applications for which the project successfully developed gasifier systems—community cooking, rubberdrying, steel re-rolling,crematoria, and so on. Al-though SDC did not directlyfund TERI in these offshootprojects, it facilitated TERI’sefforts by giving it the spaceand freedom to design and develop the required gasifier systems. A few ofthese offshoot projects are briefly described below. The first project was in asense a path-breaking initiative: to develop an industrial-sized biomassgasifier for a chemical plant.

Salt of the earth: Kharagoda

Kharagoda is a remote and arid coastal region in the Little Rann of Kutch inGujarat, about 135 km from Ahmedabad. It includes a notified ‘wildernessarea’ of about 4953 km2 that hosts gazelles, wolves, and migratory birds.

Kharagoda is also a major global source of mineral salts. The region isinundated by the waters of four rivers during the monsoon season. Thefloodwater is slowly absorbed by the soil and in time forms a sub-soil brinethat is rich in dissolved mineral salts, particularly NaCl (sodium chloride orcommon salt) and MgCl2 (magnesium chloride). The latter salt is extensively

SDC did not directly fund TERI in developinggasifier systems for numerous ‘offshoot’

applications—yet, it facilitated TERI’s effortsby giving it the space and freedom to design

and develop the systems.


used in paper manufacture,textile processing, and phar-maceutical industries. It alsofinds use in de-icing, and inthe manufacture of abrasivesand fireproof cements.

In 1915, PMW (PioneerMagnesia Works) was set upin Kharagoda to extract MgCl2

from the subsoil brine. By1996, PMW was one of theoldest and largest producersof MgCl2 in the world, with anannual output of around 7000tonnes of MgCl2 in crystallineas well as fused solid forms.

Process

PMW pumps up subsoil brinethrough borewells into shal-low open ponds, where it isallowed to evaporate in thesun. There are 23 pumpsoperating in an area of about217 acres. When pumped up,the brine has a low density—or more accurately, low spe-cific gravity—measured interms of ‘degrees Baume’(symbol °Bé). As the waterevaporates from the ponds,the brine’s specific gravity

Figure 55Evaporative ponds to

densify brine

increases from an initial 10–17°Bé to 27°Bé. At this point, all the NaCl insolution crystallizes out. The remaining liquid, called bittern, is transferredto other evaporation ponds where it is allowed to concentrate even further(Figure 55). When the bittern’s specific gravity reaches 36°Bé, it is pumpedup via storage tanks to the pre-heater vessels of the factory’s furnace (Figure 56).PMW also sources bittern from salt works such as Hindustan Salt Limited.

Figure 56Pre-heaters and main

pan of one furnace

Into the field 149

To extract MgCl2 from the bittern, other salts in solution—primarily,magnesium sulphate or MgSO4—first have to be removed. PMW does this bya process known as fractional crystallization. The bittern temperature israised to 110–130 ºC in the pre-heater vessels, when all the MgSO4 in solutioncrystallizes out in the form of ‘kieserite’ (Figure 57). The kieserite crystals areremoved from the vessels, and the remaining liquid is passed into the mainheating vessel which is kept at a temperature of around 163 ºC. Here, all theexcess water evaporates away to leave crystalline magnesium chloride(MgCl2..6H2O) in a molten state (Figure 58). The molten MgCl2 is drained into‘settler tanks’. Any remaining kieserite settles to the bottom of these tanks inabout three hours, and pure MgCl2 is skimmed off the tops of the tanks. TheMgCl2 is either poured into mild steel barrels for dispatch, or converted intoflakes and packed into high- density polyethylene bags for export.

The processes of heating and cooling the bittern demand a great deal ofprecision, because the MgCl2 has to be of 99.6% purity to be acceptable in theexport market. For heating purposes PMW depends on firewood, which istrucked in from sawmills hundreds of kilometres away. The firewood con-sumption varies according to the nature of the wood, its moisture content,and the quality of the bittern. In 1996, PMW burnt around 12–16 tonnes offirewood each day to make 20–24 tonnes MgCl2 (Figure 59). With a monthly

Figure 57Heaps of deposit from

pre-heaters, mainly kieserite


Figure 58Magnesium chloride in main evaporator

pan—notice the extent of corrosion

Figure 59One day’s firewood supply for

the two existing furnaces

Into the field 151

expenditure on firewood of nearly 600 000 rupees, the Managing Director ofthe plant, Jehangir Vakil, tried using alternate fuels such as diesel andbiomass briquettes in his furnaces. But they did not prove cost-effective. Inearly 1996, he asked TERI to examine the ways by which PMW could im-prove its technology and reduce its firewood consumption.

Assessing needs

In March–April 1996, TERI studied the plant and its various processes, inparticular, the performance of its furnaces. PMW had three massive 80-year-old furnaces constructed with firebrick walls and arches. Only two of thefurnaces were functional in 1996. Each furnace had four pre-heater vesselsand a single main heating vessel. The firewood was burnt beneath the firstpre-heater vessel, but the vessel was at a height of two metres above theflame. This led to considerable wastage of heat. The remaining pre-heatervessels, as well as the main heating vessel, were heated only by flue gases.All these vessels, too, were positioned at a height of two metres above theflue gas path (Figure 60). This reduced heat recovery, and the flue gases

Figure 60Plan, section, and overall viewof the existing furnace at PMW


escaped from the furnaces at a temperature close to 600 ºC. Not surprisingly,thermal efficiency the conventional furnaces was no more than 24%.

Clearly, there was considerable scope for decreasing firewood consump-tion and increasing energy efficiency through biomass gasification and betterrecovery of waste heat. TERI decided to design and develop an updraftbiomass gasifier for the purpose, and to reconstruct one of the two opera-tional furnaces to work on producer gas.

The gasifier was expected to reduce firewood consumption by around50%; hence, it was designed with a capacity to gasify 150 kg firewood/hour.In effect, its thermal output would be around 500 kWth (kilowatts thermal)—much larger than any gasifier TERI had designed till then. It also had thefollowing features:� it was designed to burn firewood pieces 15 cm (6 inches) in diameter and

30 cm (12 inches) in length;� a manual ‘grate-shaking’ arrangement was provided to enable removal of

accumulated ash from the grate once every half-an-hour, even while thegasifier was in operation;

� a water pit was provided below the gasifier, into which the ash would fall;and

� the hopper had a capacity of around 600 kg firewood, that is, enough fuelfor four hours’ operation.

The furnace was reconstructed on the broad principles listed below(Figure 61).� Instead of four pre-heater vessels as in the conventional furnace, the new

furnace had two large pre-heater vessels.� A new burner, capable of burning producer gas and delivering 500 kWth

power, was developed for the furnace� The burner flame directly heated the main heating vessel and flue gases

were used to heat the pre-heater vessels.� The distance between the flame and main vessel was optimized.� The path of flue gases below the pre-heater vessels was designed so as to

maximize the recovery of heat.� The vessels were supported by RCC pillars and beams, rather than by

firebrick walls.

Challenges in system development

For the TERI team, it was a formidable task to develop and commission thenew gasifier-based furnace at PMW. At that time, the team members were

Into the field 153

working on gasifiers for applications such as silk reeling and large carda-mom curing; systems with capacities of around 10 kg firewood/hour. Thecapacity of the PMW gasifier (at 150 kg firewood/hour) was truly staggeringin comparison. Besides the technical challenges of designing such a system,its very size and scale meant that TERI could not develop and test a proto-type system off-site (as it was able to do with the silk reeling and largecardamom systems). The new gasifier-based furnace had to be fabricated andtested at the PMW plant itself. This job was made all the more difficult by theremoteness of the factory site and its distance from Delhi. There were nolocal workshops where equipment and components could be made or re-paired. Most hardware had to be procured from Ahmedabad and transportedby road to Kharagoda.

By May 1996, TERI finalized the design of the new gasifier-based furnaceand sent PMW a detailed list of materials that were required to construct the

Figure 61Components of the

gasifier-based furnace


system. PMW accordingly arrangedfor all the materials—cement, sand,stone chips, steel bars, firebricktiles, and so on—to be delivered atthe factory site. PMW also arrangedfor an experienced mason to under-take the required civil work. The two new pre-heater vessels were fabricatedat Ahmedabad and delivered to the factory. The firebox for the furnace hadto be ordered from a Delhi fabricator—Punjab Engineering Works—andtransported all the way from Delhi to Kharagoda (Figure 62).

And then, in June 1996, Kharagoda was hit by a violent storm. Gale-forcewinds completely destroyed the roof of the main factory shed and causedsevere damage to other structures including one of the two operating fur-naces. PMW decided not to carry out any repairs on the furnace—in

Till then, the TERI team had beenworking on gasifiers with capacities ofaround 10 kg/hour. The PMW gasifier,

with a capacity of 150 kg/hour, wasstaggering in comparison…

Figure 62The new gasifier during fabrication: (a) main gasifier;

(b) vessels for the new gasifier-based furnace

(a)

(b)

Into the field 155

anticipation of early commissioning of the new gasifier-based furnace byTERI. Since the plant was running on just one furnace, a huge backlog oforders accumulated while the gasifier-based furnace was being set up. Thisplaced enormous pressure on the TERI team members to complete their taskat the earliest.

There were other pressures as well. PMW was a running plant with anexcellent reputation in the global market. In anticipation of increased profit-ability of operations (due to decrease in fuel costs), PMW’s Managing Direc-tor Jehangir Vakil had made commitments to his clients to sell MgCl2 atreduced prices. These commitments had to be met; the firm’s reputation wasat stake. Hence, delays and setbacks during fabrication, installation, andtesting of the new system were a source of great tension for the TERI team aswell as for Vakil (Box 31).

Box 31Salt solutions

Major problems arose while install-ing, testing, and fine-tuning the newgasifier and furnace at PMW (PioneerMagnesia Works). The pressure onthe TERI team members was intense,particularly because we were workingin a large, running factory. PMW usu-ally operated two furnaces, but wewere modifying one to operate on awood gasifier. In effect, the factorywas dependent on just one furnacefor its production while we were set-ting up our new gasifier-based sys-tem. This meant that each day’sdelay in our work, every single techni-cal glitch, had a major cost-implica-tion for the factory owner JehangirVakil.

A few of the major challenges wefaced, and their solutions, are sum-marized below.

� Initially, the flue gases simply didnot heat up the bittern in the pre-heater vessels from ambient tem-perature (37 oC). We studied theproblem and solved it by makingthe following structural and designchanges: (1) a separate blowerwas added to supply the burnerwith enough air for full combustionof producer gas; and (2) the fluegas passage was widened consid-erably to increase the contact timebetween the hot gases and thepre-heater vessels (Figure 63). Theoriginal dimensions of each of thetwo new pre-heater vessels were 8× 8 × 2 feet. Later, it was foundthat the vessels were not largeenough to meet the increased pro-duction rate of the gasifier-basedfurnace. Hence, their dimensions

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Continued


Box 31 (Continued)

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Figure 63Vessel arrangement showing flue gas

path in the gasifier-based furnace

were increased: first to 9 × 9 × 2½feet and then to 12 × 12 × 2½feet.

� The fuel hopper was provided witha castable lining material. How-ever, the lining kept separatingfrom the hopper’s metal platingduring the initial test runs, due touneven expansion and contrac-tion. The problem was finallysolved by using a 3-inch low-tem-perature (600 oC) castable liningsupported by MS bar spikes on theinner side of the hopper.

Problems such as these causeddelays and interruptions in commis-sioning the new gasifier-based sys-tem. Yet, Jehangir Vakil showedgreat patience while we tackled the

problems. He never lost his faith inthe technology, or his trust in the ca-pabilities of the TERI team. So greatwas Vakil’s enthusiasm for theproject that he actually prepared a‘table-top’ model of the new gasifier-based furnace based on the designdrawings we had sent him, and pre-sented it to our team when we arrivedat the factory! The model was beauti-fully crafted, built to scale, and incor-porated even the finer details of thenew system (Figure 64). Indeed, theproject owes a great deal to the sup-port and cooperation extended to usby Vakil and by PMW’s General Man-ager, (late) T M Babycon.

P RamanTERI

Into the field 157

Figure 64Scaled-down model of

the new gasifier

tional furnaces. With firewood costing 1200 rupees or so per tonne, its supplywas indeed a very lucrative business!) TERI’s gasifier-based furnace prom-ised to halve firewood consumption—and therefore the project team un-knowingly came into direct conflict with these vested interests among thefactory staff (Boxes 32, 33).

In early-September 1996, the TERI team operated the gasifier-based fur-nace and collected data to assess its performance against that of the conven-tional furnace (Figure 65). The results, summarized in Table 8, showed thatthe gasifier-based furnace yielded fuel savings of 60%–70% and reducedproduction time by an average of 20%.

Between 29 October and 8 November 1996, TERI conducted further com-parative tests of the gasifier-based furnace against the conventional furnace.However, these tests were inconclusive because of the reasons listed below.� The bittern used during the tests was of poor and inconsistent quality,

varying from 31 °Bé to 36 °Bé.� The main heating vessel in the gasifier-based furnace was much larger

than that in the conventional furnace. Hence, the gasifier furnace actuallydelivered more heating power than the conventional furnace for the sameincrease in temperature in both the vessels. This made the comparison ofdata difficult.

Perhaps thegreatest chal-lenge to the TERIteam’s effortscame from someof the factoryworkers them-selves. Over thedecades, thesepersons hadestablishedcovert linkageswith firewoodsuppliers to makepersonal profits.(PMW consumed12–16 tonnes offirewood daily inits two conven-


Box 32Walking on

fire

Besides technical hurdles, we facedmany other difficulties during ourproject at PMW. Kharagoda itselftook some time getting used to—itsremoteness, the bleak and arid ter-rain, the terrific storms that swept infrom the sea! Of course, JehangirVakil, the factory’s Managing Direc-tor, was kind enough to ensure thatmy colleague Sharma and I had goodaccommodation. Thanks to Vakil, wewere permitted to use the kitchen atthe plant’s guest house in which tocook our evening meal. But the feel-ing of being totally isolated from therest of the world remained during themonths we worked there…

TERI’s new updraft gasifier fur-nace would consume much less fire-wood than the conventional furnaces.We did not realize it initially; but anexus had developed between cer-tain sections of the factory staff andthe firewood suppliers. We unearthedthis network quite unintentionally.Our proposal to build a fuel-efficientfurnace posed a threat to the ele-ments that made up the network.Their resistance took many forms.False rumours were put out to dis-courage workers from helping us inour efforts. Deliberate attempts weremade to skew the results of our ex-periments with the new furnace. Andall the while we were working underimmense time pressure…

The direst threat came on a daywhen I was inspecting a shed filled

with rows of barrels containingfreshly produced magnesium chlo-ride. There was a factory employee—aforeman whom we knew was hostileto our project—standing at the otherend of the shed. I had a few ques-tions to ask him, but did not know tohow to cross over to his side. Hecalmly called out to me to walkacross the tops of the barrels. Thecontents of the barrels were at163 oC; a false step would havemeant serious burns, even death.Fortunately for me, T M Babycon—thefactory’s General Manager and astaunch supporter of TERI’s gasifiertechnology—made a timely appear-ance and actually demonstrated howone could walk across the rims of thebarrels with a little training! Resist-ance to our project quickly evapo-rated after that incident.

Once our gasifier furnace was in-stalled and successfully commis-sioned, Vakil offered an incentive (of100 rupees per day) to workers whovolunteered to operate the new sys-tem. The response was overwhelm-ing. In due course, we gave sixworkers extensive training in operat-ing the new furnace in shift mode.Since then, PMW has converted itstwo remaining furnaces to gasifier-based operation!

P Raman TERI

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Into the field 159

Box 33Caught

red-handed!

Working at Kharagoda was reallytough. The desolation was badenough. But the worst part was theresistance and hostility we facedfrom some of the factory workers.These workers had connections withthe people who supplied wood for thefurnaces. They did not like the idea ofour new furnace, because it wouldburn much less wood and so reducetheir profits. Not only were they rudeto us, they prevented their colleaguesfrom helping us in our work and alsotried in various secret ways to spoilour work.

For instance, when we first didtests to assess our gasifier furnace’sperformance, we were surprised tofind that it was not producing asmuch heat as the factory’s conven-tional furnace. Soon we discoveredthe reason: while our furnace was be-ing supplied with moist, freshly-cutfirewood, the conventional furnacewas being supplied with bone-drywood! Thereafter, we took to check-ing each and every lot of wood beingfed into our furnace.

For a while after that, things wentsmoothly. Our furnace ran day andnight without trouble; it produced

good quality crystals (of magnesiumchloride). And then, mysteriously, thequantity and quality of crystals bothfell sharply! We checked and discov-ered that someone was quietly add-ing cold bittern to the contents of thebrine-heating tank above the gasifierfurnace. This lowered the tempera-ture and concentration of the brine,and ruined the output and quality ofcrystals.

We decided to maintain a 24-hourvigil. We could see our furnace fromthe window of our room, and tookturns keeping watch on it during thenight. Sure enough, after a couple ofnights we saw someone scaling theladder up to the heating tank. Silentlywe raced across to the plant andcaught the culprit just as he waspouring bittern into the tank. He wasso surprised at our sudden appear-ance that he inadvertently dipped hisfingers in the hot brine and scaldedhimself. He turned out to be one ofthe factory’s regular furnace opera-tors…

Makhan Lal SharmaTERI

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� By the time the trials were conducted, PMW had modified its third fur-nace to run on LDO. The LDO furnace shared a common wall with theconventional (firewood-burning) furnace. Because of its relatively higherenergy output, the LDO furnace transferred part of its heat to the conven-tional furnace through their common wall and thereby improved the


Figure 65View of the gasifier systemwith the modified furnace

TABLE 8Experimental data on MgCl

2 (magnesium chloride) production

with 32°Bé bittern: conventional and gasifier-based furnaces

7 September 1996 8 September 1996

(start-off; first pan) (regular)

Conventional Gasifier Conventional Gasifier

Details furnace furnace furnace furnace

MgCl2 production (tonnes) 2 2 2 2

Firewood consumed (kg) 3945 1600 2400 700

Duration (hours) 13.25 11.75 8 5.5

Firewood consumption rate 300 136 300 127

(kg/hour)

Specific fuel consumption 1.97 0.80 1.2 0.35

(kg firewood/kg MgCl2)

Fuel saving (%) – 60 – 70

Time saving (%) – 12 – 30

Into the field 161

latter’s thermal performance. As a result the test data became skewed,again making it difficult to compare performances accurately.

Despite these factors, the test data clearly revealed that the gasifier-basedfurnace consumed less firewood than the conventional furnace for the sameamount of MgCl2 produced. As the project was nearing the end of its term,TERI advised PMW to continue monitoring and assessing the performance ofthe gasifier-based furnace by keeping a log book and recording the produc-tion data on all three furnaces. This was duly done. Indeed, till today theplant maintains impeccable records on its daily production processes.

Crystal-clear results

The gasifier-based furnace has been running continuously since 1997—roundthe clock, six days a week, for around 6000 hours each year. Not only has itreduced firewood consumption; it has also increased the production rate ofMgCl2. The conventional furnace uses dry firewood for fuel—particularly,large logs obtained from felled trees. In contrast, the gasifier can also uselocally available fresh cut-wood (typically, prosopis juliflora) with high mois-ture content. The data for the period April 1998–March 1999 illustrate thenew furnace’s viability (Figure 66).

The gasifier can achieve up to 60% fuel saving when it is charged with dryfirewood (as used in the conventional furnace). When locally available freshcut-wood is used, the gasifier still enables fuel saving of around 41%. Hence,the production cost of MgCl2 is much lower in the gasifier-based furnace thanin the conventional (firewood burning) furnace and the LDO furnace (Table 9).

TABLE 9MgCl

2 (magnesium chloride) production costwith different fuels and furnaces

Fuel and furnace Energy cost (Rs/kg MgCl2)

Firewood, conventional furnace 0.82

LDO, conventional furnace 2.42

Firewood, gasifier furnace 0.40


Figure 66Energy costs in the threefurnaces: (a) comparison

of production costs;(b) Profile of monthly fuel

savings using gasifier-based furnace, April1998–March 1999

Training and follow-up

After commissioning thegasifier-based furnace, theTERI team trained selectedPMW workers in its properoperation. This was aparticularly challengingtask, as most of the work-ers were either illiterate orhad studied only up to theprimary school level. Thefactory worked in threedaily shifts of eight hourseach. TERI trained a totalof six workers, so that twoworkers could operate thenew system during eachshift. From 1997 onwards,PMW workers have beenrunning the gasifier-basedfurnace without any exter-nal assistance.

The gasifier was madeusing 5-mm MS sheets.Because of Kharagoda’ssalty environment, thegasifier ’s walls slowlybecame corroded. In 2001,a new gasifier was fabri-cated under TERI’s super-vision to replace the oldcorroded one. TERI alsofabricated and installed acommon biomass loadingsystem to enable easiercharging of the gasifierhopper with firewood(Box 34).

(a)

(b)

Into the field 163

Box 34Skip-hoist

device

PMW’s conventional furnace had itshearth at floor level, and workersmanually brought firewood logs up tothe furnace for feeding directly intothe hearth. The new gasifier fur-nace’s fuel hopper was several me-tres above the factory floor. As aresult, it was very difficult for workersto load firewood into the hopper.

The obvious answer was to devisea mechanical system for loading thefirewood. PMW had a mobile loaderthat was used to load drums of MgCl

2

on to trucks. However, Jehangir Vakilwas understandably reluctant to usethis loader for charging the gasifierwith firewood—because it may haveheld up despatch of MgCl

2.

Having discussed the issue withVakil, I drew a rough sketch of a sim-ple ‘skip-hoist’ device that would en-able easy loading of firewood intothe gasifier’s hopper (Figure 67). In

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essence, the device comprises alarge bucket that rests in a pit on thefactory floor, and that can be raisedautomatically up to the hopper’scharging door at the throw of aswitch. Workers bring firewood in trol-leys and tip their contents into thebucket. When full, the bucket israised and the firewood emptied intothe hopper.

Vakil—himself an engineer withconsiderable hands-on experience—was most enthusiastic about theidea. He studied the sketch, made afew changes, and promptly arrangedfor a fabricator to make and installthe skip-hoist device. Not only doesthe device save considerable time incharging firewood, it also makes theprocess much safer and less arduousfor workers.

P RamanTERI

Figure 67Gasifier with skip-hoist

mechanical loadingsystem


Gasifier sans subsidy—a landmark!

In the late 1990s, MNES offered a subsidy ofup to 30% of the initial cost of a gasifiersystem. While the gasifier-based furnace wasbeing designed for PMW, Jehangir Vakilwrote to the relevant government departments asking whether and how hecould avail of this subsidy. In the absence of any response from the govern-ment, he took a commercial loan to pay for the new furnace. This marked thefirst time a gasifier furnace was sold without MNES subsidy. Vakil was sodelighted with the system’s performance that in 2002–03, he converted theremaining conventional furnace in his plant into a gasifier-based furnace. In2003, the third (LDO-burning) furnace too was modified to operate with awood gasifier. In effect, today PMW oper-ates entirely on gasifier-based furnaces.This has enabled PMW to withstand thecompetition posed by China’s entry intothe MgCl2 market in 2002–03.

Opening new avenues

The successful development and operation of the gasifier-based furnaces atPMW in Kharagoda revealed the potential of using biomass gasificationtechnology to benefit other applications/industries that require process heator generation of steam. They include:� applications that generate biomass residues;� applications already using wood/non-wood biomass to process products;

and� applications that operate boilers and have access to sources of biomass

wastes or wood.

In the wake of its Kharagoda experience, TERI successfully designed andinstalled gasifiers to supply heat for a number of diverse applications. A fewexamples are briefly described below.

Large-scale cooking in rural areas

An NGO named Gram Vikas runs a residential school for about 300 tribalstudents at Kankia village in Orissa. Earlier, the school kitchen burned

PMW’s gasifier-based furnacewas the first ever to be installed

without MNES subsidy—alandmark achievement!

The successful development ofPMW’s gasifier furnaces re-vealed the potential of usinggasifier technology to benefitother enterprises that require

process heat or steam.

Into the field 165

fuelwood in traditional hearths to cook breakfast, lunch, and dinner for thestudents. The process was extremely inefficient and slow. The daily woodconsumption was around 300–400 kg, and it took about two hours to cookbreakfast and three hours for lunch. Besides, the traditional hearths gener-ated copious amounts of smoke.

At Gram Vikas’ request, TERI developed and installed an updraft gasifier-based oven at the school kitchen in early 1999. The system worked on naturaldraft like the Sikkim gasifier for large cardamom curing, but it could also beoperated with a small (0.1 HP) blower to provide greater heating power. Thegasifier system reduced fuelwood consumption to less than 100 kg per dayand did not produce any smoke. It also saved a lot of time—breakfast couldnow be made in just one hour and lunch in two hours (Figure 68).

Figure 68Updraft gasifier-based oven for cooking at

residential school, Kankia


Green brick drying

Bricks are made from clay. Fresh clay is usually dug up from fields orriverbanks. It is cleaned, powdered, and ‘tempered’ by soaking in water togive a plastic mass, which is then moulded into ‘green bricks’. The greenbricks are dried, and thereafter fired in a kiln to yield the familiar fired-claybricks.

Green bricks contain around 25% moisture. This has to be reduced to4%–5% before the green bricks are loaded into the kiln. In dry and sunnyregions, the green bricks are piled up into a honeycomb structure and sun-dried in the open. However, in rainy regions like Kerala, the green bricks aredried by assembling them into a cylindrical bin-like structure about 8–9 feetin diameter and 6–7 feet in height, and burning logs of wood at the base ofthe bin. Typically, about 1500 green bricks are stacked in a bin, and about700–800 kg of wood is burnt to dry them over a span of two to three days.This drying method is very inefficient, and most of the heat is lost throughthe large fuel-port opening or carried away by the fast-moving flue gases.Another problem is that the drying process is not uniform; bricks in the lowerportion of the bin get over-dried, while those in the upper portion are not suffi-ciently dried.

In the year 2000, TERI designed and installed a gasifier system for dryinggreen bricks at a brick factory in Palghat, Kerala. The system used a multipleburner to burn the producer gas from the gasifier, and had a ‘flame arrester’to distribute the heat more evenly among the bricks in the bin (Figure 69).The gasifier system reduced fuel consumption by over 60% (from 700–800 kgper batch to 250–300 kg), brought down the drying time from 72 hours to24 hours, and drastically reduced smoke and other emissions.

Beas: gasifier for community cooking

Each month, on designated days, hundreds of thousands of people fromacross the globe gather on the banks of the river Beas, not far from Amritsar,to discuss and debate spiritual issues. The gathering is called Sat Sang, andcomprises followers of the spiritual leader, Radha Soami Baba. Food isserved free of cost to the gathering on each occasion and the funds for thepurpose come from donations by devotees.

Cooking for up to 200 000 people at a time poses enormous challenges.Twenty great furnaces are used to cook 2.5 tonnes of vegetables and lentilsin huge vessels; another 30–40 furnaces are used to make hot ‘rotis’.

Into the field 167

Figure 69Updraft gasifier system (operating on natural draft) forgreen brick drying: (a) schematic; (b) field installation

(a)

(b)


The furnaces burn firewood, and hence offer great potential for increasingefficiency through gasification.

In the wake of its success in installing a large-scale gasifier-based furnaceat PMW, Kharagoda, TERI offered to set up a gasifier-based furnace to re-duce firewood consumption at the Beas gatherings. The Radha Soami Babawas most supportive of the idea; to him, resources saved meant more re-sources available to help the needy. Accordingly, a giant gasifier-based fur-nace capable of burning 150 kg of firewood per hour was fabricated andcommissioned at Beas (Figure 70). The furnace provided enough heat to cookdal and vegetables for over 6000 devotees per batch. It brought about fuelsavings of over 50% and greatly improved the working environment becauseof its clean and virtually smokeless operation. A very large fuel hopper wasprovided to hold sufficient firewood for an entire day’s cooking purposes.

Figure 70Gasifier-based cooking

system at Beas

Into the field 169

The furnace was also provided with simple gas control valves to allow flex-ibility in heat supply rates (for instance, to provide ‘low’ heat to simmer thedal). Existing furnace operators were given training in the use and mainte-nance of the new system.

Besides its technical challenges, the assignment occasionally brought theTERI team face to face with situations that were unique to the spiritualnature of the Beas gathering, and that had to be handled with the greatestsensitivity (Box 35).

The Beas gasifier had a heat output capacity of over 300 kWth. A gasifier ofthis size required formal approval from MNES through a process called‘type-testing’ (Box 36). MNES allowed any R&D institution working in thefield of biomass gasification to undertake the type-testing and certification ofgasifier systems. In due course, the type-tests for the Beas system wereconducted by a joint team from the IITs Mumbai and Delhi, and the Beasgasifier became the first in the ‘above 100 kg/hour class’ to obtain a certifi-cate of approval from MNES.

Box 35Keeping

faith

The gasifier system for communitycooking at Beas proved to be a greatsuccess in terms of saving firewood.The sheer scale and power of its fur-nace also made it immensely popularwith the Sat Sang devotees—so muchso that enthusiastic devotees took topicking up firewood pieces from thenearby storage bin and tossing theminto the gasifier furnace as a kind of‘offering’. This practice quickly be-came a ritual! Thus, a curious prob-lem arose.

On the one hand, the TERI teammembers were concerned that exces-sive burning of firewood made thepractice wasteful of heat energy,negating the very purpose of the

furnace. On the other, they were ap-prehensive that preventing the prac-tice might hurt the feelings of thedevotees. After due deliberation, theteam members found a solution.They made a small, fenced-in enclo-sure directly in front of the furnaceand put up a sign in front of the fire-wood storage bin. The sign inviteddevotees to pick up pieces of fire-wood as they passed the bin andplace them in the fenced enclosure,from where they would be picked upby the furnace operator and ‘offered’in due course to the flames. The ideaworked: the devotees were happy,and the controlled burning of thegasifier furnace was re-established!

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Hot water for hotels

With increasing urbanization, the hotel industry is booming all across India.Lodges and hotels require hot water in large quantities for their kitchens andlaundries, and to meet the washing and bathing needs of the guests. Manykinds of fuels are used to heat water for these purposes—electrical power,LPG (liquefied petroleum gas), diesel, kerosene, and so on. Typically, hotwater is needed at a temperature of 40–45 °C.

In 2002–03, TERI conducted an entrepreneur training programme at itsSouthern Regional Centre in Bangalore. The programme was supported byMNES. Among the participants was Shaikh Ahmed from Chikmagalur, atown set in the hilly, thickly forested coffee plantation belt of Karnataka.Upon learning about TERI’s integrated gasifier-based system for cocooncooking/silk reeling, Ahmed hit upon the idea of using the system—withmodifications as necessary—to supply hot water to the lodges and hotels inChikmagalur.

He therefore entered into an agreement with VEE (one of the project’slicensed manufacturers) to supply the gasifier systems and to provide techni-cal support as and when needed. In August 2003, VEE fabricated and in-stalled a 10 kg/hour gasifier system at the ‘Hotel Rest Inn’ in Chikmagalur,owned by Khalil Khan. VEE also gave Khan a week’s training in operatingand maintaining the system. Earlier, the hotel had an LPG-based furnace to

Box 36Type-testing

gasifiers

After the rather unsuccessful debutin 1987 with gasifier-coupled dieselpumpsets, the government revived itsefforts to promote biomass gasifierson a wide scale in the early 1990s.Subsidy levels were lowered and setbased on gasifier ratings and applica-tions, rather than on the basis oftheir capital costs.

The government also widened therange of applications for which

gasifiers would be eligible forsubsidy. To prevent misuse of subsidyand to ensure that gasifiers met setstandards of performance, the gov-ernment established a rigorous test-ing procedure known as ‘type-testing’. Now, gasifier manufacturershave to test and obtain certificationof their products. Type-testing can bedone by any R&D institution workingin the field of biomass gasification.

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Into the field 171

heat water for its rooms. The gasifier system uses firewood, or a mixture offirewood and charcoal. It is run for just about an hour each day to meet theentire hot water requirements of the hotel (Figure 71).

Ahmed has now established a unit to supply wood-chips for the gasifiersystem. He is confident of helping set up and support many more systems inthe future.

Gasifiers for midday meals

In 1998, a charitable foundation—Adamya Chetana—was established inBangalore to provide support to economically backward sections of society,particularly women and children. To help in efforts to educate underprivi-leged children, Adamya Chetana set up a project to provide hot, tasty, nutri-tious, and hygienically cooked ‘midday meals’ to various schools in the city.The project, named ‘Annapoorna’, is supported by the Karnataka govern-ment as well as the central government.

Figure 71Gasifier system for hot water in

Hotel Rest Inn, Chikmagalur


The food is cooked in a centralized kitchen in the heart of Bangalore. Eachday, thousands of meals have to be made ready and packed for dispatch by1230 hours, so that they can be transported to reach schools all over the cityduring the lunch-break (between 1300–1330 hours). Thus, the kitchen startsoperating around 2200 hours each night and works till around 1130–1200hours the next morning. An efficient system of testing the quality of food isin place. Voluntary agencies provide vehicles to transport the packed mealsto schools.

Initially, the Annapoorna project kitchen met its entire fuel needs fromLPG cylinders. In mid-2004 Ravi Kumar, proprietor of VEE, saw the potentialof using biomass gasifiers instead of LPG to supply heat for the kitchen.Back-of-envelope calculations indicated that the use of gasifier-based heatwould save around 50% of the cost incurred on LPG. Kumar studied the fuelrequirements of the kitchen and then approached Adamya Chetana with asimple but effective proposal.� VEE would install a gasifier at the Annapoorna kitchen, replacing one of

the two existing LPG burners. Adamya Chetana would not have to pay forthe capital cost of the gasifier.

� VEE would also take care of biomass supply for the gasifier and its day-to-day running, maintenance, and repair.

� VEE would ensure that the gasifier provided as much thermal energy aswas earlier being supplied by the LPG burner.

� Adamya Chetana would pay VEE the amount that it had earlier beenspending on LPG, for a period of one year. After one year, the gasifiersystem would become the foundation’s property and it would be free torenew the contract with VEE on suitably modified terms and conditions.

The arrangement proved mutually beneficial, so much so that AdamyaChetana has since acquired a second gasifier-based system to supply heat forthe Annapoorna kitchen on the same terms and conditions (Figure 72).

‘Because of the gasifiers, we are able to save a lot of money on fuel costs,’says Bhaskar, production manager at the Annapoorna kitchen. The gasifiersystems provide a substantial portion of the kitchen’s total heat require-ments. LPG cylinders are still used by the kitchen—but primarily as a back-up system when the electric power supply fails and the gasifiers’ air blowerscannot function. Currently, the Annapoorna project provides meals to over54 000 children in 90 schools—and the demand is growing.

Into the field 173

Gasifier-based cremation

Hindus traditionally cremate their dead. Each day, an estimated 20 000–30 000 bodies are cremated across India. Each cremation requires between400–600 kg of firewood, and about five million tonnes of firewood are con-sumed each year in this practice. Besides leading to depletion of forests,traditional cremations have a grim fallout on the environment. Often, bodiesthat are not wholly burnt are cast into streams and rivers, leading to danger-ous pollution of water resources (Figures 73 and 74).

Figure 72Gasifier system for midday meal scheme at Adamya

Chetana Foundation: (a) downdraft gasifiers; (b) boilers

(a)

(b)


Figure 73Cremation along

riverside

Figure 74Wood stacked oncremation pyre

Into the field 175

Alternate systems are available for cremation, but they are based on costlyfossil fuels such as diesel and furnace oil or on electricity whose supply isundependable. The crematoria themselves are expensive to set up: a typicalelectric or diesel crematorium costs around two million rupees and thecremation charges range between 300–500 rupees each.

The government tried to promote the setting up of electric crematoriaalong the banks of the river Ganga under its GAP (Ganga Action Plan)project. However, the electric crematoria could not provide adequate servicebecause of frequent and prolonged power cuts, and the long time required bythem for initial heating.

System development

Under a project sponsored by MNES, TERI developed an energy-efficient andenvironment-friendly gasifier-based cremation system at its research stationin Gual Pahari. To start with, TERI made a prototype cremation systemcomprising a downdraft wood gasifier and a combustion chamber lined withfirebrick (Figure 75). The producer gas from the gasifier was distributedthrough ducts to the cremation chamber. A total of seven burners were pro-vided in the cremation chamber: three burners along the length of each of itstwo walls, and one additional burner at the end where the head would be

Figure 75Lab prototype testing at TERI’s Gual Pahari campus:(a) view from burner side; (b) view from gasifier side

(a) (b)


located. Trial runs were carried out to test the viability of the system and toachieve reliable performance. After a series of tests and improvements indesign, a complete cremation system comprising gasifier, air pre-heater,producer gas burner, and cremation chamber was fabricated by 2M Indus-tries, Mumbai, for field-testing. One major modification was to replace themultiple burners used in the earlier prototype by a single large burner withpre-mixing of hot air (Figure 76).

Nagarik Sewa Mandal, an NGO located at Ambernath (Thane district,Maharashtra), agreed to cooperate in field-testing the improved prototype atthe Ambernath municipal crematorium. This NGO has a unique mission: itoffers free cremation services to all. After obtaining permission from the

Figure 76Pre-heating of air (using hot chamber exhaust) for supply to

gas burner, and temperature profile of the chamber

Into the field 177

Ambernath Municipal Corporation, the improved prototype cremationsystem was installed for field-testing at the Ambernath municipal cremationgrounds near Mumbai in February 2002 (Figure 77).

The very nature of the undertaking posed unique challenges to the TERIteam (Box 37). Initial tests were carried out on unclaimed corpses lying in themunicipal morgue. Once the gasifier system had proved its capability, aformal public demonstration was organized on 31 July 2002. The eventreceived wide coverage in many local newspapers, and on the Marathi televi-sion channel E-TV (Box 38, Figures 78 and 79). The very next month, at least10 cremations were carried out using the gasifier system.

Following the successful installation of the gasifier-based crematorium atAmbernath, two more systems were fabricated by 2M Industries and set upin Goa, with support from the local legislator’s development fund (Figure80). Currently, another five gasifier-based crematoria are in the process ofbeing set up in Himachal Pradesh. Of these, two have already been fabri-cated and will be installed at Sundernagar and Sanjauli-Shimla (Figure 81).

Figure 77Field-testing of gasifier-based crematorium at

Ambernath (Maharashtra)


Box 37A grave

undertaking

I was part of the team that set up thegasifier-run cremation system inAmbernath. The testing of the proto-type system at Gual Pahari was itselfquite a challenge. We needed to cre-mate corpses to make sure that thecremation chamber worked properly.But how and where were we to getcorpses? Finally, we asked local vil-lagers to bring us carcasses of goatsand other animals. These were dulybrought and cremated to test the sys-tem’s efficiency…

Other challenges awaited us atAmbernath. To start with, a pit had tobe dug at the cremation ground to laythe foundations of our gasifier sys-tem. The locals were unwilling tohelp, so I took up a spade andstarted to dig the pit alone. At once,my spade hit a layer of human bonefragments. The layer was two feetthick! In the daylight it was not toobad. But I had to work late into thenights, when the only light came fromthe pyres all around me, when drugaddicts and other strange creatureslurked in the shadows…it certainly

was a little eerie then, standing in avast sea of human bones!

But the greatest challenge camewhen we started operating the sys-tem. For the first time, we would becremating human bodies. We real-ized there was just no room for mis-takes, especially in the presence ofgrieving relatives of the deceased! Tobuild up confidence in the gasifiersystem—in the observers’ minds aswell as in our own—we decided tostart with unclaimed bodies at themunicipal morgue. This meant ob-taining special permission in each in-stance from the local police andmunicipal authorities. However, theywere very cooperative, especially af-ter the local councillor intervened onour behalf. We knew some of thosecorpses must have belonged to hard-ened criminals, yet in each case welaid a small floral wreath and said abrief prayer before performing thecremation…

Lal BabuTERI

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Each cremation in the gasifier-based system takes approximately 60–80minutes, and consumes just 100–150 kg of wood (as against 400–600 kg woodin the traditional pyre) (Figure 82). The gasifier-based system costs around0.5 million rupees and its payback period works out to around two yearswhen compared to other traditional systems of cremation. Its economic

Into the field 179

Box 38Balancing tradition with

conservation

Most Hindus are still deeply influ-enced by religious rituals connectedwith death and attach great signifi-cance to cremating the dead in thetraditional way—on a pyre of woodlogs. But with a greatly increasingpopulation and large-scale destruc-tion of forests, it is becoming moreand more difficult to get wood logsnowadays. There is also the seriousproblem of pollution.

Recently, though, an engineerfrom Sambhajinagar (Aurangabad)named Sanjay Mande—presently at-tached to TERI—has successfully de-veloped a crematorium that works ongas made from wood! This systemtries to strike a balance between thetradition of cremation by burningfuelwood on the one hand, and theneed to conserve fuelwood on theother. Mande was inspired to developthis system in 1995 when he saw thehuge amounts of fuelwood that wereconsumed at the Nigambodh Ghatcremation grounds in Delhi.

After many futile attempts to ob-

tain support for the project, TERIfound an ally in Nagarik SewaMandal, a voluntary organizationbased in Mumbai. After nearly eightyears of hard work a wood gas-basedcrematorium has been successfullyset up and demonstrated at theAmbernath cremation ground. TheAmbernath Municipal Corporationhas shown interest in its regular use,as it will save wood, money, and time.A traditional (open-pyre) cremationconsumes around 300–500 kg ofwood and takes three to four hours.The gasifier-based crematorium con-sumes only 150 kg wood, takes amere 70 minutes, and also drasti-cally reduces pollution. Most impor-tant, the new system can also beoperated on wood waste pieces andloose biomass in briquette form.

—Translated excerpts from featuretitled ‘Sambhajinagar youth makes awood gas-based crematorium’ in theMarathi paper Deogiri Tarun Bharat,

Sambhajinagar, 4 August 2002

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viability is further enhanced in big cities like Mumbai, where the cost offirewood logs used for traditional cremation is much higher than in thetowns and rural areas. The higher cost of firewood in metropolitan citiesbrings down the payback period of the gasifier-based system from two yearsto a mere six months or so.


Figure 78Field demonstration of system at Ambernath

(31 July 2002)

Into the field 181

Figure 79Articles in local media on the

new cremation system

Figure 80Gasifier-based crematorium

installed at Phonda, Goa


Figure 81Gasifier-based crematorium installed at

Sundernagar, Himachal Pradesh

Figure 82Economic comparison of different

kinds of crematoria

Gasifiers for drying rubber

India is the fourth largest producer of natural rubber in the world, afterThailand, Indonesia, and Malaysia. In 2001–02 the country produced 631 400tonnes of natural rubber from a total planted area of 558 592 hectares. Rubber

Note Prices relate to 2001–2002

Into the field 183

is mainly cultivated in a narrow 400-km belt along the western coastline,extending from Kanyakumari district of Tamil Nadu in the south to theDakshin Kannada and Kodagu districts of Karnataka in the north. Naturalrubber is primarily used to make tyres for the automobile industry. It is alsoconsumed in the manufacture of a vast range of products ranging frommattresses and footwear to toys and battery boxes, and finds extensive use inmaking roads, vibration absorption, and soil stabilization.

Rubber is collected from trees in the form of latex, which is dried to con-vert it to rubber crumbs. The drying of latex is carried out in tunnel dryersheated by furnaces that use electricity or diesel oil. After drying, the rubbercrumbs are cooled and pressed into blocks for despatch to various rubber-based industries.

Powerless with power subsidy?

To promote the rubber processing industry, the government provided elec-tricity to new crumb rubber units at a special subsidized rate of 0.50 rupeesper kWh (kilowatt hour) for the first five years, after which normal rateswould be applied. This subsidy on electricity was meant to strengthen thefinancial position of crumb rubber units in the first five years of their opera-tion. Unfortunately, it had exactly the opposite effect. With the rising electric-ity costs and increased competition in the late 1990s, many rubber processingunits were just not capable of making the sudden transition—from operatingon heavily subsidized power for five years, to suddenly having to pay forpower at much higher rates. A large number of units shut down, while othersswitched to diesel as an alternate fuel.

Replacing diesel by biomass

On an average, about 40 litres of diesel is consumed to make one tonne ofrubber. As diesel costs make up a large proportion of processing costs, greatpotential exists for using biomass gasifiers instead of diesel to bring downfuel costs and thereby increase the profitability of units.

TERI recognized this potential in 2000–01 when, on one of its several tripsto Bangalore, the TERI team visited a rubber factory at the request of itsowner. After studying the drying process, TERI developed a biomass-basedgasifier drying system. To fabricate the first system TERI approached Para-mount Enviroenergies, a manufacturing firm based in Alwaye. The proprie-tor of the firm, Bobby Abraham, was initially cautious about venturing into


gasifier technology, for it had never been tried out before by crumb rubberunits. Inquiries about the new technology brought Abraham into contactwith Jehangir Vakil of PMW, Kharagoda. Vakil was enthusiastic in endorsingthe financial and environmental benefits of gasifier technology. Accordingly,Paramount Enviroenergies fabricated the first gasifier-based drying systemfor crumb rubber units under TERI’s supervision. The system was success-fully installed and tested in March 2001 at Alwaye Rubex Pvt. Ltd, Alwaye.The gasifier ran on cashew shells, and was integrated with the existingtunnel dryer at the factory.

In 2002–03, the Rubber Board announced a subsidy of 30% on gasifier-based drying systems. This encouraged other rubber drying units to adoptthe new technology. The Rubber Board also extended support to the manu-facturers of gasifier systems. As a result, the prices of the systems fell, givinga further fillip to their replication. In 2002, three more gasifier systems basedon wood and coconut shells were fabricated and installed by ParamountEnviroenergies (Figure 83). Till now, the firm has manufactured and set up atotal of 10 gasifier-based drying systems in various crumb rubber dryingunits in Kerala (Box 39).

Figure 83Gasifier-based system for drying crumb rubber in Kerala:

(a) downdraft gasifier; (b) close-up of burner flame; (c) updraft gasifier

(a)

(b)

(c)

Into the field 185

Box 39Tappingpotential

The first gasifier system was adowndraft model; it ran on cashewshells. We faced major challenges inintegrating the system with the tun-nel dryer used to dry crumb rubber.But the TERI team helped us solvethe problems. Later, when we experi-mented with using other kinds ofbiomass fuels—coconut shells, rub-ber wood chips and so on—it wasagain the TERI team, and particularlyDr Kishore’s hands-on approach andleadership, that enabled us to suc-ceed.

There is very great scope for usingbiomass gasifier technology—not onlyfor thermal applications but also forpower generation. We can save hugeamounts on diesel costs. In Kerala,we are so rich in biomassresources…and gasifier technologyallows us to use these resources in asustainable way. Take rubber planta-tions: today they stretch fromKanyakumari and Nagercoil in thesouth all the way across centralTravancore up to Kasaragod and be-yond in the north. The benchmark forthe renewal of forest cover in rubberplantations is 25–30 years. So, thereis always a steady supply of woody

biomass from these plantations. Therubber wood mostly goes to the furni-ture industry—but the twigs andbranches can feed our gasifiers!

There is one major challenge,though: getting dry biomass. Keralais a heavy rainfall area. Althoughbiomass is available in plenty, supply-ing it in a dry condition is a problem,particularly during the monsoonmonths. To overcome this difficulty,we have modified our gasifier designto work on the updraft principle—thisallows use of fuel with higher mois-ture content. Some users have alsostarted to buy dry biomass fuel fromneighbouring Tamil Nadu. The fuel isbought during the summer months; itcomes well-packed in gunny bags andis stored away to tide over the rainyseason.

Now, with TERI’S assistance weare exploring the possibility of devel-oping a dryer for biomass fuel! Theidea is to tap a portion of the heatgenerated by the main gasifier sys-tem and use it to dry moist biomassfuel.

Bobby AbrahamParamount Enviroenergies

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In developing the gasifier-based drying systems for crumb rubber units,TERI learned a few important lessons.� Gasifiers become economically attractive to entrepreneurs if the subsidy

on conventional fuel is reduced—as has happened in the case of diesel.� Institutional support (such as that provided by the Rubber Board) is very


important in promoting innovative technologies such as biomass gasifica-tion.

� For users, the all-important issue is the profitability of operations. Usersdo not mind making large investments on a gasifier system or in creatinginfrastructure for such a system, provided it has proven to be economical.

� While developing and fabricating a gasifier system, there are great advan-tages in working with an entrepreneur/firm belonging to the target clus-ter or area (such as Bobby Abraham of Paramount Enviroenergies). Suchcollaboration enables quick development and testing of systems tailor-made to suit local requirements, makes it easier to fine-tune systems afterinstallation, and ensures faster penetration of the market.

TAKING STOCK

In setting out to develop biomass gasifier technology for thermal applica-tions, TERI faced a particularly challenging task. As many as six instituteswere receiving huge funds from MNES to support various programmes todevelop biomass gasifiers—but TERI was not one of them. It was indeedvery hard for TERI to work without government funding and to makegasifier systems that could hold their own in a field flooded with highly-subsidized products developed by MNES-supported programmes.

Yet TERI succeeded. It began with small forays into the silk reeling andlarge cardamom industries. These small initiatives met with mixed results,but later they branched out into a great number of activities that have todayestablished TERI as a leader in thermal gasifiers. Till now, TERI has devel-oped a variety of gasifier-based systems for over a dozen thermal applica-tions in SMiEs. There are over 350 TERI gasifier systems in the field with acumulative installed capacity of around 14MWth. TERI has licensed eightIndian manufacturers and one Sri Lankan manufacturer for further promo-tion of gasifier systems (Figure 84).

Technology development and dissemination

TERI’s experience has shown that the development of gasifier technologyand its successful dissemination is an iterative process that begins with aninitial assessment of user needs and resources. The process generally in-volves several revisions, as tests on a prototype gasifier in the laboratory andin the field yield data on technical and economic performance during opera-tion; data vital to making improvements to the gasifier and evaluating its

Into the field 187

Figure 84 (a)TERI gasifiers in the field:

spread of systems


Figure 84 (b)TERI gasifiers in the field:licensee manufacturers

Into the field 189

Figure 84 (c)TERI gasifiers in the field:

growth in numbers and installed capacity

viability. Often these tests also involvegetting feedback from users onwhether and to what extent thegasifier matches their needs.

As the gasifier design evolves andmoves closer to the manufacturingstage, industrial design issues need to be considered. Can the gasifier beeasily manufactured? Are its components easily assembled? Is it user-friendly? Is it pleasing to the eye? Such issues play a significant role inensuring the gasifier ’s acceptance in the market. Indeed, issues such aspricing, sales strategies, and distribution channels need to be resolved evenbefore any commercial production can commence, for they are vital to ensuredelivery and uptake of the gasifiers.

Efficient maintenance and repair services play a critical role after gasifiersystems are installed. Such services not only ensure smooth and continuedoperation of the gasifiers, but by creating client satisfaction they establish thecredibility of the systems in the market and thereby provide a great boost totheir large-scale dissemination.

Efficient maintenance and repairservices play a critical role after

gasifier systems are installed. . . andprovide a great boost to large-scale

dissemination.


Box 40The power of

fuel prices

Mohan Kulkarni of 2M Industries,Mumbai sees great potential forbiomass gasification in thermal appli-cations. But he feels its wide-scaleadoption will require basic changesat policy levels, particularly on issueslike fuel pricing and subsidies. Hepoints out that several industriesused diesel as fuel so long as itsprice was kept low, thanks to govern-ment subsidy; their interest inbiomass gasification grew only whenthe price of diesel went up (after sub-sidy was reduced).

‘The case of LPG is similar,’Kulkarni observes. ‘It continues to beheavily subsidized today, ostensiblybecause it is meant for domesticcooking. But LPG cylinders are beingwidely used as fuel by a great manysmall-scale enterprises! There is

great scope for these enterprises toswitch to biomass gasifiers instead ofLPG to meet their fuel needs, but thiswill happen only when the subsidieson LPG are reduced or removed.’

He also sees enormous potentialfor gasifier-based power generation—especially in rural areas, wherebiomass is available in plenty. 2M In-dustries fabricated a biomassgasifier-based power plant that wasput up by TERI and Gram Vikas atKanheiput village, in Orissa. ‘I re-member the villagers’ delight andwonder when the plant was commis-sioned and they saw electric lampslight up their village for the first timeever. It was so moving, our heartswent out to them. And still thereare so many other villages likeKanheiput, waiting for power…’

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Potential for gasifier technology—manufacturers’ views

Any factory or enterprise that uses heatin its process is a potential client forbiomass gasifiers, provided biomass iseasily available. The large-scale adoptionof biomass gasifiers also depends to alarge extent on the policies related to fuel-pricing, particularly the pricing of petroleum-based fuels (Box 40).

Chanderpur Works is another firm licensed to make large-scale biomassgasifiers based on TERI’s design. Chanderpur Works is located inYamunanagar, about 190 km from New Delhi, and manufactures and exports

Any enterprise that uses heat in itsprocess is a potential client for

biomass gasifiers—providedbiomass is easily available. The

adoption of gasifiers also dependson pricing policies related to

petroleum-based fuels

Into the field 191

equipment for cement, paper, fertilizer, lime, and brick plants. It has madeand sold eight gasifier-based systems, equivalent to 500 kWe (kilowattselectrical) in energy output, to various units within a 25–30 km radius ofYamunanagar.

‘The main reason for our success is the easy availability of biomass inYamunanagar,’ explains Sudhir Chandra, proprietor of the firm.‘Yamunanagar has a large and thriving plywood industry. Hence, biomass inthe form of plywood waste is available in bulk quantities throughout theyear and at very low prices.’

Chanderpur Work’s gasifiers are designed to burn wood-chips of up to6 inches (150 mm) in size and containing up to 15% moisture. Among thefirm’s clients are a copper smelting unit and a steel re-rolling mill; each usesa 100 kg/hour biomass gasifier to supply heat. Both these units are emi-nently satisfied with their gasifiers. Each gasifier saves them around 50 000rupees per month (2005 prices) in terms of furnace oil, implying a paybackperiod of less than a year.

Bound by red tape/lack of awareness

Chandra feels that a major constraining factor in the spread of gasifier tech-nology is the delay in obtaining formal approval of systems from MNESunder its type-testing process. Chanderpur Works itself faced a two-yeardelay (from 2000 to 2001) in obtaining certification of its gasifier model,because of the differences in results reported by the two testing agencies (IITDelhi and IIT Mumbai).

Another constraint is the reluctance of banks to finance biomass gasifiers.According to Chandra, banks regard such systems as ‘new’ or ‘unproven’.Chanderpur Works had to install its first system on 50% credit terms becauseits client could not obtain bank finance for acquiring the gasifier. The remain-der was paid only after the client operated the system satisfactorily andgenerated enough surplus to make payment.

Even when banks do finance purchase of biomass gasifiers, they do notrelease full payment to Chanderpur Works till they receive the appropriatesubsidy on their loans from the government. The result: Chanderpur Worksremains out of pocket for at least one year. Sudhir Chandra feels thatbiomass gasifier technology for thermal applications must be pushed by twosimple measures:� a transparent and efficient finance mechanism that will benefit both the

manufacturers and the clients; and


� creation of awareness, among policy makers, financiers, and industrialists,about the immense benefits that the technology offers.

Future potential and challenges

India, being an agricultural country, produces huge quantities of biomassand offers great potential for the use of thermal gasifiers. According to aTERI study, about 246 million tonnes of agro-residues are produced in Indiaeach year, out of which about 100 million tonnes remain unutilized.19 Interms of energy equivalence, this amounts to 200 million tonnes of Indiancoal—an enormous quantity, considering the fact that the annual coal pro-duction is around 227 million tonnes.

However, till today gasifiers are unable to use a large fraction of thesebiomass resources. Viable technologies to utilize agro-wastes such as mus-tard stalk, groundnut shells, and corn cobs are still not available. Even wheregasifiers have been developed to use such wastes, their field performanceremains an issue. If biomass gasification technology is to take off, ways mustbe found to convert varieties of biomass into forms that can used as fuel bygasifiers. Development of biomass briquetting and pelletization technologieswill enable the utilization of a vast range and quantity of agro-residues.

In the past two decades, major efforts have been made to develop large-sized gasifiers that can take advantage of the economics of scale in deliveringenergy services. However, there remains a great need for small gasifiers thatcan be used in applications where the energy requirements are smaller—particularly in rural areas and among SMiEs.

Entrepreneurs who wish to set up gasifier-based systems face great diffi-culties in getting what they want under one roof. Their needs include thefollowing:� an attractive financial package by which to acquire the new system (e.g., a

leasing arrangement, to spare the client from the burden of a one-timepayment);

� a well-trained and dependable team that can install, test, and commissionthe new gasifier system and related equipment;

� regular and dependable fuel supply (e.g., dry wood-chips of a certainsize);

19 TERI (The Energy and Resources Institute). 2003. Development of Gasifier-based Crematorium.TERI Report no. 1999BE63. New Delhi: TERI.

Into the field 193

� maintenance services;� repair services; and� training facilities for operators.

One way to meet these needs is by establishing an ESCO (energy servicescompany). In simple terms, an ESCO is a firm that can provide, under oneroof, all the needs of a client who adopts or wishes to adopt an energy-efficient technology. The services offered by an ESCO include any or all ofthe following:� analysing the needs of a client;� design, fabrication, installation, and commissioning of the new system;� devising financial packages;� supply of fuels and spares;� maintenance and repair services; and� training of personnel.

Even more important, effective commercialization and marketing strate-gies must be formulated for gasifier systems tailored to meet the needs ofSMiEs. The challenges are many, and a few are listed below.� There is a general lack of information in the SMiE sector about the poten-

tial for and economics of gasifier technology.� There are few, if any, institutional structures to facilitate the promotion of

gasifier systems among poorer and non-skilled users.� Although a sizeable number of gasifiers have been produced and installed

in the country, manufacturing capacity for gasifiers is still very limited.Even among existing manufacturers, many are small workshops or fabri-cators. Thus, the increase in installed gasifier capacity has come aboutmainly through one-by-one replication of models manufactured on asmall scale, rather than by mass production of systems by large firms. Thelatter path could bring down the cost of systems by taking advantage ofthe economics of scale, as well as enable standardization of systems andbetter quality control.

THE WAY FORWARD

Biomass energy sources currently contribute about 11% of the global primaryenergy supply. Their share is much greater (and therefore more important) indeveloping countries. In India, biomass sources account for an estimated34%–41% of the country’s primary energy supply. In other developing coun-tries such as Uganda, over 90% of the people depend on biomass energy.Caught between the rising prices of fossil fuels on the one hand and develop-ment needs on the other, most developing countries are looking veryseriously at biomass sources to supply their energy needs in future.

TERI has acquired considerable knowledge and experience in biomassgasification technology, and helped develop gasifier-based systems for awide range of thermal applications as well as for power generation. In thecourse of its work, TERI has also encountered various hurdles on the path towidespread deployment of this technology. Hence, while making efforts toscale up and mainstream the use of biomass gasifiers for providing thermalenergy services, TERI is using a systematic approach to build on past experi-ence and avoid potential pitfalls. The focus of TERI’s efforts will be onselected applications that appear to have the greatest potential for large-scalegasifier deployment in terms of technical, economic, and financial feasibilityas well as social, economic, and environ-mental benefits.

Given their shared interest in biomassenergy, developing countries must worktogether to find better ways to use theirrich biomass resources. In other words,there is a very strong case for South–Southcooperation in using biomass gasification

Caught between rising fossil fuelprices on the one hand and

development needs on the other,most developing countries arelooking seriously at biomass

sources to supply their futureenergy needs


technology to meet present as well as future energy needs. In 2003–04, a jointteam of researchers from Harvard University and TERI undertook a study ofthe potential for and challenges of using biomass gasifiers to meet energyneeds in developing countries. The study, supported by the World Bank,built upon the experience and lessons gathered in India by TERI and othersduring their efforts to develop and disseminate gasifier systems for thermalapplications as well as for electricity generation.20 In the course of its currentactivities, TERI will use its experience and expertise in gasifier technology tobring about socio-economic development in rural areas—not only in Indiabut also in other developing countries (Boxes 41, 42, 43).

From March 2000, SDC and TERI have initiated a policy research projectto facilitate the promotion and adoption of efficient biomass-based technolo-gies in rural/small industries in India. The project aims at the following:

20 Ghosh D, Sagar A, and Kishore V V N. 2004. Scaling up biomass gasifier use—applications,barriers and interventions. Paper no. 103, Environment Department Papers, Climate Change Series.Washington, DC: The World Bank.

Box 41Tobacco curing

in Myanmar

In Myanmar, gasifier technology canbe used in community cooking,sericulture, and other small enter-prises and rural industries. It canalso be used to provide electricity inremote rural areas.

Under the BIMST–EC (Bangladesh,India, Myanmar, Sri Lanka, Thailand–Economic Cooperation) Energy SectorCooperation Programme, TERI hassupplied biomass gasifier technologyfor tobacco curing to Myanmar withfunding support from the Ministry ofExternal Affairs, Government of India.A biomass gasifier system with a ca-pacity of 50 000 kcal (kilocalories)/hour output has been set up by TERI

near Chinbyit-kyin and Kokke vil-lages, Myingyan Township for the cur-ing of tobacco (Figure 85). TheDepartment of Forests, Governmentof Myanmar is the local implementa-tion agency for the project.

The thermal gasifier uses local ag-ricultural residue as its mainfeedstock and is expected to reducefuel consumption by up to 50% in thetobacco curing industry. It will pro-vide opportunities to the local com-munities of Kokke and Chinbyit-kyinvillages to increase their incomesfrom the tobacco curing industry, aswell as bring substantial environmen-tal benefits.

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The way forward 197

Figure 85Gasifier system installed in Myanmar for tobacco

curing: (a) downdraft gasifier; (b) tobacco curing barn

(a) (b)

� identifying important biomass-using industries in Karnataka andRajasthan;

� investigating the existing environment for the promoting efficientbiomass-based technologies; and

� facilitating the introduction of efficient technologies.

TERI has undertaken studies in Rajasthan and Karnataka to examine thepotential of using biomass gasifiers for thermal applications in the rural andSMiE sectors. The studies have helped identify a number of areas in whichpilot projects can be launched. Initiatives have already been launched in thepuffed-rice sector in Karnataka. Other areas include food processing unitsthat make khoya (a type of milk cake) and namkeen (sweets and savouries) inRajasthan; units that dry agricultural produce such as ginger and turmeric;


Box 42Uganda project: gasifiers for

rural development

Uganda is rich in biomass resources—a reflection of the country’s extensiveforests and agricultural base. Amongthe biomass materials available arewood and sawmill wastes, sugar canebagasse, rice husk, and wastes fromcoffee, tea, and cotton plantations.Studies by the Ugandan governmentindicate that almost 97% of the coun-try’s population—mainly rural dwell-ers—depend on wood fuels as theirmain source of energy. Hence, enor-mous potential exists for the use ofbiomass gasifiers for thermal appli-cations as well as for electricity gen-eration.

In 2002, the Ugandan governmentestablished a 10-year rural develop-ment programme titled Energy for Ru-ral Transformation or ERT, supportedby a grant from the Global Environ-ment Facility through the World Bank.ERT aims to bring about socio-eco-nomic transformation of Uganda’s ru-ral areas by developing the ruralenergy sector. The lead agency forERT is Uganda’s Ministry of Energy &Mineral Development.

In 2004, TERI won a bid to supportthe ERT programme by providing ex-pertise in biomass gasification tech-nology. TERI’s activities will cover thefollowing areas:� introduction of biomass gasifica-

tion technology in Uganda throughdemonstration projects;

� setting up a testing facility to as-sess the potential of various agro-wastes as biomass feedstock;

� developing a national training pro-gramme on gasification technol-ogy; and

� developing a roadmap for futuredissemination of gasifier-basedtechnology in Uganda.

To assist in implementing the pro-gramme, three sites have been cho-sen to set up demonstration plantsthat will create maximum awarenessamong the local populace.� Two gasifier-based power plants

(1 × 100 kWe and 1 × 50 kW

e) will

be set up at the Nyabyeya ForestryCollege. The college has majorproblems in getting electricity fromthe grid; sometimes, it has to gowithout power for two weeks at astretch. The gasifier-based powerplants will provide a steady anddependable source of power to thecollege campus, besides servingas a tool for creating awarenessand providing education to the ru-ral entrepreneurs who receivetraining at the college.

� A gasifier-based system for institu-tional cooking will be set up atKing’s College Budo (about 15 kmfrom Kampala City’s centre). Thiscollege has been producing someof the topmost bureaucrats,

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Continued

The way forward 199

Box 42 (Continued)

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engineers, etc. in Uganda. It has acanteen catering to around 1200students. At present, the canteenuses seven wood-stoves thatconsume around two tonnes ofwood each day.

� A 10 kWe gasifier-based power

plant connected to a gas enginewill be set up at Khyambogo Uni-versity. This system will be mainlyused for demonstration, and sometraining programmes will be devel-oped around it too.

TERI will also help to set up abiomass testing facility at MakerereUniversity, and conduct feasibilitystudies on supplying electricity toKalangala Island (located on Lake

Victoria) from a gasifier-based powerplant. To build local capacity in gasifi-cation technology, TERI proposes totrain selected personnel fromUganda in the design and manufac-ture of gasifier-based systems.

In May 2005, the TERI team under-took a mission to Uganda. A meetingwas held with all the stakeholdersand detailed presentations weremade on gasifier technology and itsbenefits. After the meeting, a gasifiermodel was operated by the team togive the participants first-hand expe-rience of its working. The TERI teamalso demonstrated a gasifier modelat an exhibition held at City Square,Kampala (Figure 86).

Figure 86Gasifier model being shown atexhibition in Kampala, Uganda


cold storage units; metal processing industries; and institutional cookingenterprises. TERI will work with local institutions and technology providersfor delivering customized technological solutions to the industries/enter-prises concerned. In Karnataka, efforts have been made to get SHGs (self-help groups) and community-level organizations to facilitate the promotionof biomass gasification technology; for instance, by acting as agents orbiomass fuel suppliers.

Gasifiers will be designed to burn specific kinds of loose biomass (such asrice husk, lantana, pine needles, and so on) and tested in the field. TERI willalso facilitate the formation of a gasifier manufacturers’ platform to promotemutual exchange of information, and initiate dialogue with relevant govern-ment departments to promote large-scale dissemination of biomass gasifiersfor thermal applications.

Box 43Bio-energy for heat

applications in South Asia

Under a grant from the Global Envi-ronment Facility, a full-scale projecttitled ‘Reducing greenhouse gas(GHG) emissions by promotingbio-energy technologies for heatapplications’ is being prepared forimplementation in the South Asiancountries of Bangladesh, Bhutan,Nepal, and Sri Lanka. The project isbeing executed by FAO (Food andAgriculture Organization), while UNEP(United Nations Environment Program)is the implementing agency. Theproject aims at reducing greenhousegas emissions in both industrialand domestic sectors in the target

countries through the promotion ofenergy-efficient biomass-based tech-nologies.

TERI has been chosen by FAO toprovide technical, logistical, and ad-ministrative support in preparing theproject document. In particular, TERIis preparing a regional backgroundreport to identify improved biomass-based technologies that can becommercialized in the region, the po-tential markets that exist for them,and the barriers that must be over-come in promoting them and ensur-ing their adoption.

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ANNEXURES

TECHNOLOGY SOLUTIONS FOR

SERICULTURE

ANNEXURE 1

H I S TORY OF S ILK

Silk was discovered in China between 2697–2597 BCE, during the reign of thegreat Emperor Shi Huang Ti. According to Chinese legend, an empressnamed Lei Tzu picked some cocoons from a mulberry tree and was playingwith them when she accidentally dropped one in her tea. In attempting toretrieve it, she discovered that it had unravelled into a long, fine strand ofsilk! The empress thereafter came to be known as Si Ling-chi: ‘Lady of theSilkworm’.

The Chinese soon undertook extensive cultivation of mulberry for makingsilk. The process by which cocoons were made into silk was kept a closelyguarded secret; only finished threads and fabrics were allowed to leave thecountry. Merchants took Chinese silk through the famous Silk Road toTurkey, Greece, and Rome, where the exotic material fetched fabulous prices.Alexander the Great knew of silk, and attempted to wrest control over thelucrative silk trade by extending his conquests to cover parts of the SilkRoad. It is believed that silk cultivation began in India around 400 CE, whena Chinese princess married an Indian prince and brought with her somemulberry seeds and silkworm eggs.

Today, India ranks second only to China in silk production (Table A1-1).Besides being the second-largest producer of silk in the world, India is alsothe world’s largest consumer of silk. In 2004–05, India not only producedraw silk and silk wastes totalling to 20 087 tonnes, but also imported 7948tonnes of silk. Most of the silk is used to make saris.

Besides mulberry silk, India produces three other varieties of silk: tussar,muga, and eri (Box A1-1). Certain kinds of raw silk yarn are also made fromsilk wastes, that is, by-products of cocoon processing (Box A1-2).

OVERVIEW OF

SERICULTURE


Box A1-1Non-mulberry

silks

� Tussar silk is produced from co-coons of several species of moth(Antheraea mylitta, Antheraeaproylei, and others) that live in thewild. The tussar silkworm usuallyfeeds on oak leaves. In 2004–05,India produced 322 tonnes oftussar raw silk.

� Muga silk is produced in the stateof Assam (‘muga’ means amber inthe Assamese language, indicat-ing the colour of the cocoon).Muga is produced from cocoons ofthe Antheraea assama westwoodmoth—a species endemic to theBrahmaputra valley and theadjoining hill tracts. Muga silk is

famous for its beautiful goldensheen, which actually improveswith ageing and washing. The silk-worms commonly feed on leaves ofplants such as the Som and Soalu.Around 110 tonnes of muga rawsilk were produced in 2004–05.

� Eri silk gets its name from the cas-tor plant, whose leaves providefood for the eri silkworm (in San-skrit ‘eranada’ means castor). Erisilk cannot be extracted from co-coons by the usual reeling proc-ess; instead, it has to be ‘spun’(see Box A1-2). About 1448 tonnesof eri silk were produced in2004–05.

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TABLE A1-1Raw silk: annual production, including

wastes (thousand tonnes)

Country 2000 2001 2002 2003

India 15.2 15.9 17.3 17.3

China 78.2 94.2 100.1 101.5

World 107.0 131.8 140.8 132.4

Source Table 74: Raw silk: annual production (including wastes). Food and Agriculture

Organization (www.fao.org).

Annexures 205

Box A1-2Silkenjargon

The world of silk has a language allits own! Listed below are a few com-monly used words.� Denier The word describes the

thickness of the silk filament in acocoon. The higher the denier, theeasier it is to reel off the silk with-out breaking the strand. In gen-eral, Indian raw silk suffers fromvariation in its denier (that is, thethickness of its silk threads is notuniform). As a result, the threadstend to break during winding andweaving, particularly in powerlooms. In contrast, Chinese silkhas better denier and greaterstrength as well; hence, weaversprefer working with Chinese yarn.

� Dupion This is a rough, irregularsilk produced from ‘double’ co-coons, that is, cocoons that havebeen spun side to side by two silk-worms, interlocking the pair andmaking it necessary to processthem together.

� Filature This term is used for rawsilk that is reeled by machine, asdistinct from hand-reeled silk.

� Noil yarn This is a silk yarn madefrom short fibres that are removed

during the making of spun silk.Noil is mainly produced inKarnataka and Tamil Nadu.

� Spun silk This is a silk yarn madeup from short lengths of silkthread. Usually, such threads areobtained from eri cocoons, andalso from silk wastes and piercedcocoons. Spun silk has a charac-teristic brilliance. However, it isweaker than silk and tends to be-come ‘fuzzy’. Special machinesare used to spin the yarn.

� Univoltine, bivoltine, andmultivoltine As with other in-sects, the silkworm moth’s life cy-cle can be described in terms ofthe time that elapses between amoth laying an egg and the emer-gent moth becoming an adult andlaying its own eggs. This elapsedtime is called ‘generation time’. Ifthe moth has a one-year-longlifecycle (that is, if there is onlyone generation per year), it iscalled ‘univoltine’. If there are twogenerations per year, it is called‘bivoltine’; and if there are manygenerations per year, it is called‘multivoltine’.

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STATE PRESENCE IN THE INDIAN S ILK INDUSTRY

Considering the political and socio-economic importance of the silk industry,the government has created separate departments of sericulture in statessuch as Karnataka, Andhra Pradesh, and Tamil Nadu (indeed, Karnataka hasa full-fledged sericulture ministry). These departments are primarily responsiblefor drawing up and implementing plans—including a range of subsidy


schemes—to promote the growth and development of sericulture. Special-ized institutions have been set up to provide support to the silk industry inareas such as cocoon supply, sale of raw silk yarn, machinery manufacture,training, and R&D. Some of these institutions are briefly described below.

Central Silk Board

Central Silk Board (CSB) was constituted under an Act of Parliament in 1948to provide support to the silk industry by way of R&D, extension, and train-ing. CSB has six full-fledged research and training institutes at variouslocations in the country. Three institutes—at Mysore (Karnataka),Berhampore (West Bengal), and Pampore (Jammu & Kashmir)—focus onmulberry silk, the institute at Ranchi (Jharkhand) focuses on tussar silk, andthe one at Mendipathar (Meghalaya) on eri silk. The sixth institute, atBangalore, carries out R&D in post-cocoon technology.

CSB also provides mulberry silkworm seeds (that is, eggs) to cocoonrearers under the NSSP (National Silkworm Seed Project). Thirty-five silk-worm seed production centres have been set up in different states to producedisease-free seeds for sale to rearers. To provide healthy young silkworms torearers, CSB has set up 318 silkworm rearing centres in various states.

Central Silk Technological Research Institute

Central Silk Technological Research Institute (CSTRI) was established atBangalore in 1983 by CSB to undertake R&D activities related to silk technol-ogy—particularly, in the post-cocoon areas. Over the years, CSTRI has set up25 sub-units in important silk clusters across the country.

CSTRI’s objectives include the following:� improving the quality of silk products (raw silk, spun silk, etc.);� upgrading machinery used in reeling, spinning, and weaving of silk;� providing training and technical consultancy services to the industry;� providing facilities to test cocoons, fibre, yarn, fabric, dyes, and chemicals

used in the industry; and� information dissemination.

Central Sericultural Research and Training Institute

Central Sericultural Research and Training Institute (CSRTI) was establishedby CSB in 1961 at Chennapatna (Karnataka); in 1963, it was shifted to

Annexures 207

Mysore. CSRTI conducts R&D activities primarily in the pre-cocoon areas ofthe silk industry. Its major objectives include development of the following:� superior mulberry and silkworm strains;� cost-effective cultivation practices;� technologies for the detection and management of pests and diseases of

mulberry and silkworm;� improved rearing technologies; and� appropriate farm machinery for mulberry cultivation.

To translate laboratory results to the field, CSRTI has set up a two-tierextension network comprising five regional sericulture research stations, tenresearch extension centres, and three technical service centres in differentparts of Karnataka, Tamil Nadu, and Andhra Pradesh.

Cocoon markets

The government has set up cocoon markets at major silk reeling clusters,where the rearers bring their cocoons for display and sale. Minimum pricesare set for various categories of cocoons by government regulators. Thereelers inspect the different varieties and grades of cocoons, and purchasethem through auction. The bidding process is transparent, and settlement isimmediate and in cash. The cocoon markets in Ramanagaram andSiddlaghatta are among the largest in the world. The quantities of cocoonsthat are auctioned daily vary greatly according to the seasons—from 20tonnes to 70 tonnes in each market. On average, around 40 tonnes of cocoonsare traded daily at the Ramanagaram market and 30–35 tonnes at Siddlaghatta.

Silk exchanges

To help silk reelers sell their raw silk yarn, the government runs silk ex-changes in Karnataka and Tamil Nadu. Each day, government regulators fix arange of prices for various grades of raw silk brought in by reelers. Traderscan then buy the silk through auction; the reelers are paid within two days(spot payment). A considerable amount of silk is traded outside the ex-changes as well. However, here the reelers almost always have to sell theirproduce on credit to the traders or their agents. As a result, they are out offunds for periods that vary from a few days (when the buyers are localtraders) to over six months (as is the case with weaver-merchants of Surat,who settle their dues only twice a year).


MAK ING RAW S ILK FROM COCOONS—PROCESS

The process of making raw silk from cocoons essentially involves two broadstages:� rearing cocoons; and� reeling the cocoons to make raw silk.

Rearing cocoons

Like all other moths, the mulberry silkworm moth (Bombyx mori) passesthrough four stages in its life: egg, caterpillar, pupa (or chrysalis), and per-fect insect (moth). The female moth lays 200–500 eggs at a time. The eggs(popularly known as ‘seeds’) are laid out on trays filled with mulberryleaves, where they hatch out into silkworms (that is, caterpillars) about 2 mmlong. The silkworms eat voraciously, grow rapidly, and become about 30 mmlong after 4–5 weeks. During this time, they change their skins four times.After the final skin change, the silkworms are shifted carefully on to bamboomounts where they proceed to make their cocoons (Figure 87).

Figure 87Silkworm rearing: (a) on mulberry leaves;

(b) on bamboo mat (‘chandrike’)

(a) (b)

Annexures 209

Each silkworm extrudes twin silk threads in fluid form through twoglands in its mouth, together with a gummy substance called sericin. Bymoving its head from side to side, the silkworm lays the silk threads in aseries of 8-shaped figures to form a filament. The sericin sets hard and bindsthe filaments together, forming the walls of the cocoon. Making the cocoontakes about eight days. It takes another three or four days for the silkworminside to transform into a pupa or chrysalis. As the days pass, the cocoonhardens and develops into an ovoid shape with the chrysalis inside.

Harvesting cocoons—timing it right

If the cocoon is left undisturbed, after around 15 days the pupa transformsinto a moth that ‘pierces’ (that is, splits) the cocoon and emerges. The mothwill mate, lay eggs, and die—completing the life cycle. In piercing the co-coon, however, the moth breaks the cocoon’s silken filaments.

The best silks are made up of long, continuous strands. Hence, the pupaeinside cocoons must be killed before they transform into moths. On the otherhand the pupae must not be killed too soon, lest they decay and ruin thequality of the cocoons’ silk. This means the cocoon rearer has to judge exactlywhen his cocoons are ready to be harvested. He has to factor in the time itwill take for the cocoons to be gathered, sorted, and transported to the co-coon markets, to ensure that the cocoons are not pierced in transit. The rearerdoes not kill the pupae; this task is left to the silk reeler.

Reeling the cocoons

There are three main stages in making raw silk from cocoons:1 stifling;2 cooking and reeling; and3 re-reeling, skeining, and book-making.

Stifling

Having purchased the cocoons, the silk reeler first has to kill the pupaeinside them. This process is called ‘stifling’. Usually, the cocoons are placedin a covered basket or a barrel and exposed to a blast of steam or hot air for afew minutes. Stifling allows cocoons to be stored for some days. In general,stifling with hot dry air allows the cocoons to be preserved for a longer timethan steam stifling. There is an advantage in this: the reeler can purchase


good-quality cocoons when their prices are low, stifle them, and store themfor later use when cocoon prices are higher or when good-quality cocoonsare no longer available in the market.

Cooking and reeling

To reel off silk from cocoons, the silk reeler uses a special piece of equipmentthat resembles a large spinning wheel. This is called a silk reel; it can beturned mechanically or by hand. The cocoon is first placed in a basin of hotwater for a short while (30 seconds to a minute or two). This process is called‘cooking’; it softens the sericin, and reveals the ends of the silk thread ofwhich the cocoon is made. The reeler then tugs on the thread, deftly passes itthrough an eyelet, and places it in a groove on the turning silk reel to removethe entire length of thread (Figure 88). A single cocoon can have 400–500metres of thread. In practice, reelers unwind several cocoons at a time on tothe reel, where the various threads are treated as one. As the reeling of athread nears completion, a fresh thread is twisted on to it; the softenedsericin helps bind the threads together to make one long, continuous strand.The processed or ‘spent’ cocoons (essentially comprising pupae remains) areremoved from the reeling basins and sold to pupae dryers (Box A1-3).

Box A1-3Down to the last

thread…

Every single portion of the cocoonfinds some use. While the silkthreads are removed during the reel-ing process, a cruder form of silk col-lects over time on the surface of thehot water in the reeling basins. Thissilken layer is skimmed off, dried,and sold to spun silk units. The dis-carded pupae are sold to unorgan-ized collecting agents, who in turnsell them to pupae dryers—a differentcommunity of workers altogether. Thepupae dryers are very poor; they

dwell in ramshackle settlements onthe outskirts of major silk reelingclusters. They soak the gatheredpupae in shallow ponds of water andthen leave them to dry in the sun.This loosens the scale-like surfacesof the pupae (called the paleadelayers), from which the dryers removesome more crude silk for sale to spunsilk units. The final residue is rich inprotein; it is used in making poultryfeed and dog biscuits.

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Annexures 211

Figure 88Silk reeling operations: (a) cottage basin cooking oven; (b) reeling

basins; (c) re-reeling of yarn; (d) skeining and bundling of yarn

(a)

(b)

(c)

(d)


Types of reeling units

Reeling units fall under two main categories: charka units and cottage basinunits. In the charka unit, the same basin is used for cooking cocoons andreeling of silk. In the cottage basin unit, cooking and reeling are carried outin separate basins. These two kinds of units have been described in the maintext of this book

Traditional cottage basin ovens vary greatly in design as well as dimen-sions. Some ovens have horizontal grates, while others have inclined step-grates; some have one chimney while others have two. The dimensions of thehearths vary widely, as do the arrangements of cooking basins and the sizesand shapes of water drums (Figure 89).

Figure 89Variations in cottage

basin ovens

Re-reeling,skeining, andbook-making

The reeled silk isusually moist. It isdried while beingrewound on to reelsof a standard size (aprocess called re-reeling). The heat fordrying is usuallyprovided by charcoaltaken from the oven.Thereafter, the yarnis twisted into loosecoils and knotted; aprocess calledskeining. Finally, theskeins are gatheredinto bundles weigh-ing 2–4 kg each(called ‘books’), andsent to the market.

Annexures 213

As described in the main text, CSTRI had developed and promoted a numberof ‘economic’ cocoon cooking ovens aimed at reducing fuelwood consump-tion by silk reeling units (Figure 90). SDC was concerned at the lack of up-take of these economic ovens, and commissioned TERI to carry out anin-depth study of the issue. Hence, TERI conducted a detailed survey in1993–94 of various kinds of ovens used in silk reeling units in Karnataka,Andhra Pradesh, and Tamil Nadu. Such a study had never been attemptedbefore. TERI’s pioneering survey was unique in another respect: data were

Figure 90CSTRI economic ovens:

(a) charka (b) cottage basin

(a) (b)

ANNEXURE 2

FIELD SURVEY OF SILK

REELING OVENS


gathered from actual studies and measurements of processes, rather than onthe basis of questionnaires. To assist in the collection of field data, the TERIteam employed students from local engineering colleges. In all, TERI covered236 cooking/reeling ovens and 94 stifling ovens during the survey. Of thecooking/reeling ovens surveyed, 186 were in Karnataka, and 25 each inAndhra Pradesh and Tamil Nadu (Table A2-1). They included traditionalcharka and cottage basin ovens, as well as CSTRI economic ovens (charka andcottage basin).

The survey identified certain broad characteristics of the traditional charkaand cottage basin ovens, as summarized in Tables A2-2 and A2-3.� The majority of charka ovens do not use fuelwood; instead they use a

variety of loose biomass fuels. Often, mixtures of different kinds ofbiomass are used depending on seasonal availability (for example, paddyhusk is used along with coffee bean shells).

TABLE A2-1Survey of silk reeling units:

break-up of ovens

State Region Type of oven No. of ovens

Andhra Pradesh Madanapally CSTRI charka 25

Karnataka Ramanagaram Cottage basin 39

Charka 21

Kanakapura Cottage basin 38

CSTRI cottage basin 6

Devanahalli Charka 16

Cottage basin 15


Kolar Cottage basin 14

Charka 16

Kollegal CSTRI cottage basin 2

CSTRI charka 16

Charka 2

Tamil Nadu Palacode Cottage basin 7


Charka 17

Total 236

Annexures 215

Table A2-2Select survey data: traditional and

CSTRI charka ovens

Cocoons Specific fuel Specific energy

processed consumption consumption

No. of units (kg/day) (kg/kg cocoons) (kcal/kg cocoons)

Fuel type (calorific

value in kcal/kg) Trad. CSTRI Trad. CSTRI Trad. CSTRI Trad. CSTRI

Groundnut shell (4900) 16 26 10.6 13.04 2.44 2.77 11 952 13 586

Paddy husk + coffee 2 10 12.88 9.62 1.58 1.78 6 378 7 170

bean shells

Eucalyptus leaves 20 – 11.42 – 3.26 – 17 365 –

(5324)

Source Mande S, Pai B R, and Kishore V V N. 2000. Study of stoves used in the silk reeling industry.

Biomass and Bioenergy 19(2000): 51–61.

TABLE A2-3Select survey data: traditional and

CSTRI cottage basin ovens

Cocoons Specific fuel Specific energy

processed consumption consumption

No. of units (kg/day) (kg/kg cocoons) (kcal/kg cocoons)

Fuel used Trad. CSTRI Trad. CSTRI Trad. CSTRI Trad. CSTRI

Tamarind wood 60 7 82.34 75.41 1.65 1.16 8007 5614

Maize cobs 4 1 72.00 89.00 1.48 1.21 5512 4491

Neem wood 22 1 44.26 49.00 1.71 1.88 8101 8873

Source Mande S, Pai B R, and Kishore V V N. 2000. Study of stoves used in the silk reeling industry.

Biomass and Bioenergy 19(2000): 51–61.


� Cottage basin ovens mostly burn woody biomass in the form of wood logs.� In both charka and cottage basin units, the cooking and reeling basins

cannot be covered with lids. As a result, significant heat loss takes placedue to continuous evaporation.

� Daily fuel consumption in charka ovens ranges from 17–27 kg for slow-burning fuels (such as paddy husk and sawmill wastes) and 26–37 kg forfaster-burning fuels (such as groundnut shells or eucalyptus leaves).

� Daily fuel consumption in cottage basin units varies from 50–285 kg,depending upon the number of basins installed in each unit (two to eight).Consequently, there is wide variation in the amount of cocoons processedper day by units (and hence, the amount of silk produced daily).

� The specific fuel consumption (that is, the amount of fuel consumed toprocess 1 kg of cocoons) tends to be higher for faster-burning fuels thanfor slower-burning fuels.

The survey also revealed the reasons why the CSTRI’s ovens had notbecome popular. These ovens had been designed to save fuel, and indeedgenerally performed better than traditional ovens when operated properly; butthey required fuelwood charging and burning practices that were very differ-ent from those used in traditional ovens. This had led many reelers to modifyor change the design of the CSTRI ovens on their own (Figure 91). In doingso, they ended up reducing the ovens’ efficiency (Box A2-1).

Figure 91Modifications made by reelers in economic ovens:(a) additional chimney installed by reeler; (b) metal

door kept open so that longer logs can be fed

(a)

(b)

Annexures 217

ENERGY AUDITS

During the survey, the TERI team performed very detailed energy audits in anumber of units. The exercise presented many challenges. The very nature ofthe silk reeling process makes it difficult to study and quantify the heat

Box A2-1CSTRI economic

ovens

CSTRI’s ‘economic’ ovens had fea-tures that made them capable of re-ducing fuel consumption if usedcorrectly. The ovens were offered toreelers at subsidized cost under theNational Sericulture Project: 50% inthe case of CSTRI charka ovens, and30% in the case of CSTRI cottage ba-sin ovens. TERI’s survey revealed thatin terms of specific fuel consumption(kg fuel/kg cocoons), the CSTRI cot-tage basin ovens generally performedbetter than the traditional cottage ba-sins for a given fuel. Yet, the CSTRIovens failed to become popularamong reelers. There were two majorreasons.� The CSTRI oven had a small door

for fuel feeding. The door helpedreduce heat losses while the fuelwas being burned. However, it alsomeant that fuelwood had to bechopped into small pieces beforebeing fed into the oven. This en-tailed additional labour and costsfor the reeler. The door also madeit difficult to remove ash residuesfrom the hearth.

� The CSTRI oven was not designedto burn loose biomass fuels suchas husks, cobs, and the like.

To get around these perceived‘drawbacks’, many reelers hadchanged the recommended operatingpractices or modified the ovens’structures on their own. However, intrying to tackle one problem they onlysucceeded in creating additionalproblems. For instance, in order tomake the charging of fuelwoodeasier, some reelers operated theoven with its door open, while othersremoved the oven door entirely. Suchpractices increased the heat lossfrom the hearth—which meant morefuelwood had to be burned forprocessing a batch of cocoons. Re-moval of the door also caused imbal-ance in the air draught in the oven, asa result of which the furthermostcooking basins no longer receivedsufficient heat. To restore the bal-ance in the air draught, some reelersreplaced the original chimney with alarger one, while others added extrachimneys. These measures only in-creased heat losses and further de-creased the thermal efficiency of theoven. The overall effect was to reducethe popularity of the CSTRI ovens.

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losses that occur at different stages of the process. For instance, the cookingand reeling basins are not provided with lids. Therefore, heat is continuouslylost due to evaporation of water from the basins. Heat is also lost in transfer-ring cocoons and hot water from the cooking basins to the reeling basins, andin replacing the dirty hot water at the end of each batch with fresh cleanwater. Heat is wasted in the form of hot flue gases and hot ash, and radiatesaway from the oven surface to the air. To assess thermal efficiency, the teamshad to trace the many heat flow patterns and measure a large number ofparameters (Figure 92). These included the following:

Figure 92Project team carrying out detailed energy and water audit of

ovens: (a) measuring water consumption; (b) weighingcocoons for water carry-over; (c) weighing cocoons processed

(a)

(b)

(c)

Annexures 219

Figure 92 (Continued)Project team carrying out detailed energy and water audit of ovens:

(d) weighing pupae waste; (e) measuring fuelwood consumption;(f) measuring flue gas losses; (g) water boiling test;(h) measuring pre-heater drum water temperature

(d)

(e)

(f)

(g)

(h)


� type of fuel, its cost, and the amount consumed (for a day’s production ofsilk);

� the quantity of cocoons processed per day and the amount of silk pro-duced;

� the total amount of water consumed for processing a batch of cocoons;� the quantity of water shifted from cooking basins to reeling basins;� the temperatures of water in the drum, cooking basins, and reeling basins;� oven surface temperatures; and� flue gas temperatures.

On the basis of the audits, TERI found that all ovens used in silk reelingunits —whether traditional ovens or CSTRI ovens, charkas or cottage basins—had very low thermal efficiencies, in the range of 12%–15%. Hot flue gasescarried away an estimated 40% of the input heat. Hence, the survey indicatedthat there was great potential to improve energy efficiency in both charka andcottage basin ovens (Figure 93).

Annexures 221

Figure 93Sankey diagrams: (a) charka

(b) cottage basin oven

(a)

(b)


FROM LAB TO F IELD

Mark 0: proof of concept

As described earlier, TERI put together a gasifier-based model oven, Mark 0,at its research facility in Gual Pahari. Mark 0 had a downdraft gasifier; itgenerated comparatively less tar and particulate matter than an updraftgasifier, and hence the producer gas was relatively clean. Mark 0 was madeprimarily to demonstrate that gasification technology could be used to cookcocoons. A prototype six-pan cottage basin oven was fabricated using sixthin stainless steel vessels procured from a household-goods store in Delhi. Abiogas burner was placed beneath each vessel; each burner was providedwith a gate valve to regulate gas flow. All six burners were connected to thegasifier through a pipeline, and a blower installed to push in air for combus-tion through the pipeline to the burners. The vessels and burners wereplaced in a closed MS box (Figure 94).

The vessels were filled with water and heated by burning the producergas from the gasifier. To examine the possibility of using flue gases for pupaedrying, the project team fabricated a ‘cabinet tray drier’ comprising traysmade from aluminium and MS sheets (Figure 95). Hot flue gases from theoven were led through the drier and allowed to escape through the chimney.Cocoons or pupae were not available in Delhi. Hence, the team placed water-soaked cotton plugs (of sizes similar to cocoons), leaves, pieces of bread, andother materials on the trays to examine the drier’s performance. Although noexperimental data were collected during the trial runs of Mark 0, several keyobservations were made, both positive and negative, on the performance ofthe gasifier.

ANNEXURE 3

THE HINDUPUR

EXPERIENCE

Annexures 223

Figure 94Mark 0 prototype gasifier: (a) overall view; (b) gasifier

along with blower and air–gas mixing chamber; (c) close-upof six-pan cottage basin oven used in Mark 0

(a)

(b)

(c)


Positives

� The burner efficiency could possibly be improved to about 50%. With theconversion efficiency of biomass to producer gas being about 70%, thisimplied that a gasifier-based oven could achieve an overall thermal effi-ciency of 35% (compared to 10%–15% for traditional ovens). This wouldtranslate into about 50% savings in fuel.

� In a traditional oven, it is not possible to control the amount of heatsupplied to individual cooking vessels. Water is boiled in all the vesselsirrespective of the quantity of cocoons in them, leading to wastage of fuelat low production levels. Mark 0 provided the ability to control individualgas burners, and to switch off the burners if and when necessary. Thiswould enable the reeler to save fuel.

Figure 95Close-up of cabinet tray

drier used in Mark 0

Annexures 225

� Mark 0 produced relatively clean flue gases compared to the traditionaloven. Experiments with the cabinet drier showed that the flue gases couldbe used to dry pupae. The dried, smell-free pupae could be sold to gener-ate additional income for the reeler.

Negatives

� The pipeline that carried gas from the gasifier to the burners tended to getblocked by deposits of tar and particulate matter, and therefore requiredfrequent cleaning.

� Fuelwood pieces tended to get jammed in the throat of the gasifier—aphenomenon called bridging. Also, the fuel storage capacity of the hopperwas small, and hence, frequent fuel-feeding was necessary.

� The burner power (which directly depended on the rate of supply of gasto individual burners) showed great fluctuation. It was felt that this wasdue to the small capacity of the gasifier.

Mark 1: laboratory model

Based on its observations, the project team made a few modifications in theMark 0 gasifier and other components to evolve a second improved labora-tory prototype, Mark 1-Lab (or Mark 1-L).

Experiments with Mark 0 indicated that the tar and particulate content ofthe producer gas was maximum during the initial ignition or starting-upperiod of the gasifier, which took 5–15 minutes. The tar and particulatecontent fell to lower levels once the fuel-bed reached a high and uniformtemperature. Hence, a separate ‘flare’ pipe was provided in Mark 1-L to leadaway and burn off impure producer gas during the start-up period.

To clean the producer gas to some extent, a ‘gas cooling chamber’ wasintroduced in Mark 1-L immediately after the gasifier outlet (Figure 96). Inessence, the cooling chamber comprised an inverted tank placed in a largertank filled with water. Hot, raw producer gas from the gasifier was bubbledthrough the water in the lower tank. The tar and particulate matter in the gassettled at the bottom of the tank, and the cleaned gas was led away from theupper tank.

Tests and results

Mark 1-L was operated at Gual Pahari for eight hours daily (as would be thecase in an actual silk reeling unit) for about a month. The idea was to test the


system’s reliability under continuous operation and to pinpoint routinemaintenance requirements. To assess the prototype’s performance, param-eters such as the rates of fuel consumption, gas flow, water heating, andevaporation were monitored on a continuous basis. The results showed thatwhile the burners operated with over 50% efficiency at lower rates of gasflow (that is, lower input power), their efficiency dropped to 25%–35% athigher input powers. Thus, there was need to improve the performance ofthe burners. On the positive side, the problem of pipeline blockage observedin Mark 0 was almost eliminated in Mark 1-L with the introduction of a flarepipe and bubbling chamber.

Mark 1: field model

Design and development

The next step was to develop a field prototype (Mark 1-F) and test it againsta traditional cottage basin oven at a suitable silk reeling unit. A site to testMark 1-F was chosen: Kedar Silk Reeling and Twisting Unit at Hindupur,Andhra Pradesh. The aim was to identify problem areas in Mark 1-F’s designand performance, and to adapt the system to actual field situations.

Figure 96Gas cooling

chamber

Annexures 227

Before designing Mark 1-F, it was first necessary to gather baseline dataon the performance of the Kedar unit’s existing cottage basin oven. The unithad not been covered under TERI’s earlier survey. The project thereforeconducted an energy audit. The audit revealed that Kedar’s existing ovenconsumed significantly higher amounts of fuel (2.18 kg/kg cocoons) than thetypical six-pan traditional oven (average specific fuel consumption 1.70 kg/kg cocoons). This appeared to be due to a combination of low productionlevels, poor oven design, and poor operating practices. These factors weretaken into account while determining the design and dimensions of the Mark1-F oven (Boxes A3-1 and A3-2).

The cooling chamber used in Mark 1-L had proved quite effective incleaning the producer gas. To reduce costs, the project decided to make thecooling chamber of Mark 1-F from old oil drums instead of GI sheets. Two oil

Box A3-1Mark 1-F: sizing

for power

Mark 1-F was the first ever gasifieroven to be tried out in the field. Todetermine the design and dimen-sions of the Mark 1-F gasifier, it wasnecessary to evaluate the perform-ance of the Kedar unit’s existingoven. This was done by carrying outstandard WBTs (water boiling tests)on a row of three cooking vessels inKedar’s six-pan oven.

The WBT was simple in principle,but required measurements of highaccuracy. A measured quantity ofwater (seven litres) was poured intoeach cooking vessel, which was thencovered with a lid and heated. Therate of increase in water temperaturewas recorded each minute thereaftertill the water reached boiling point.Figure 97 shows the results of the

WBTs. The middle vessel in the rowreceived the maximum thermalpower—taking just around 17 minutesto bring its seven litres of water toboil. This translated into a ‘useful’thermal power level of about 2 kW

th

(kilowatts thermal).The Mark 1-F gasifier was there-

fore designed to provide 2 kWth

toeach of its six cooking vessels, thatis, to provide 12 kW

th useful thermal

power. Assuming burner efficiency of50%, this meant that the gasifierwould have to supply the six burnerswith a total input power of 24 kW

th.

This in turn translated into a pro-ducer gas flow rate of 21 Nm3/hour(normal cubic metres per hour). Fromthis figure, the Mark 1-F gasifier’ssize and design were worked out!

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drums—one smaller than the other—were used, with the smaller druminverted over the larger. Other cost-cutting measures included the following:� using insulation in the firebox zone alone, and not in the entire fuel

hopper;� reducing the pipeline size from 1.5 inches to 1 inch;� selecting a blower of 0.5 HP capacity instead of the earlier 1 HP blower;

and� reducing the thickness of MS sheet used from 3 mm to 2 mm.

By adopting these various measures, the cost of the gasifier was reducedby almost half: from 25000 rupees for Mark 1-L to 13000 rupees for Mark 1-F.

After finalizing Mark 1-F’s design, two identical gasifiers were fabricatedat a workshop in Delhi. One unit was assembled and operated for a week tocheck and confirm its reliability of performance. Thereafter, the second unitwas packed and sent by road transport to Hindupur in October 1995. Prior toits arrival at Hindupur, a preliminary survey was carried out by the projectteam to identify a fabricator, wood supplier, and mason. At the Kedar unit, aspace was identified for setting up Mark 1-F and necessary structuralchanges (such as breaking down a boundary wall) were carried out.

Figure 97Water boiling test results for three

different cooking vessels

Annexures 229

Box A3-2Mark 1-F: shaping

the hopper

TERI’s field survey had revealed thaton an average, a traditional six-pancottage basin unit consumed around160 kg fuelwood daily to process 95–100 kg cocoons. This gave an aver-age SFC (specific fuel consumption)of 1.70 kg/kg cocoons. The energyaudit of the Kedar unit showed thatits SFC was much higher than the av-erage (2.18 kg/kg cocoons). Ratherthan aim at achieving this lower levelof performance, the project decidedto design Mark 1-F to achieve an SFCof 1.70 kg/kg cocoons.

Trials with Mark 0 and Mark 1-Lhad indicated that the gasifier ovenwould yield fuel savings of 50% ormore. This meant that Mark 1-Fshould be designed to burn (160 ×0.5) = 80 kg fuelwood daily. To re-duce the need for frequent chargingof fuelwood, the project decided toprovide Mark 1-F with a hopper thatcould hold half-a-day’s supply (that is,40 kg) of fuelwood. The idea was thatfuel charging could be done at thestart of the day, and once later onduring the lunch break.

The question was: what should thehopper’s shape be? Mark 1-L had acylindrical hopper; but to hold 40 kgfuelwood, such a hopper would haveto be around two metres in height!This would make it very difficult tocharge fuelwood or to lock/unlockthe hopper door. An option was to usea conical hopper. However, the majorproblem with a conical hopper wasfuel movement: wood pieces wouldnot move freely if the slope of thecone was low.

The project team therefore experi-mented with hoppers of differentshapes and sizes. Fuelwood pieces ofvarying sizes were loaded into eachhopper; the hopper’s bottom platewas then removed and the movementof fuel observed. Based on these ex-periments, the project finally decidedto use a conical fuel hopper with an80º slope and capacity of 40 kgfuelwood (preferably cut into 4-inchpieces). The height of this hopperworked out to 0·75 metre (Figure 98).

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Installation, trials, and results

Mark 1-F was fabricated and installed at Hindupur in November 1995. Instal-lation of the gasifier oven involved the following steps:� casting of gasifier firebox insulation;� construction of the oven; and� assembly of the gasifier and its associated sub-systems.


Figures 99, 100, and 101show the step-by-step installa-tion of the Mark 1-F oven.Unlike the earlier lab proto-type, which was made of steel,the Mark 1-F oven was con-structed using bricks andferro-cement slabs and sheetsto match the existing oven’sstructure as much as possible.

Mark 1-F was commissionedin November 1995 and run fora total of 36 days till March1996. A woodcutter wasinstalled at the Kedar unit tosupply cut-wood pieces of

Figure 98Experimenting with different hopper shapes for

smooth fuel movement: (a) cylindrical fuel hopperand choke plate; (b) conical fuel hopper

Figure 99Casting of gasifierfirebox insulation

(a) (b)

Annexures 231

Figure 100Various stages during construction of the gasifier-based

cottage basin oven: (a) making MS bar structure; (b) castingtop slab with vessels; (c) construction of brick pillars;

(d) installation of pre-heater drum; (e) installation of top slabwith vessels; (f) installation of pupae dryer

(a) (b)

(c) (d)

(e) (f)


Figure 101Gasifier system installed at Hindupur:

(a) gasifier; (b) cooking oven with pupae dryer

Annexures 233

4–5 inches for the gasifier(Figure 102). To compareMark 1-F’s performance withthe existing oven, cocoonsfrom the same lot wereprocessed in batches in bothovens during February–March 1996, and data gath-ered on a total of 13comparative tests.

The results were largelyencouraging. On an average,while the traditional cottagebasin oven burned 2·34 kgfuelwood to cook 1 kg ofcocoons, the Mark 1-F ovenburned only 1·34 kgfuelwood for the purpose. Ineffect, the Mark 1-F ovenreduced fuel consumption bynearly 50%. Also, a chanceobservation indicated thatthe field prototype improvedthe yield of silk by a smallbut significant amount. In silk reeling, productivity is measured in terms of‘renditta’—the weight of cocoons needed to produce one kilogram of rawsilk. While the traditional oven showed an average renditta of 7·72 (that is, itrequired 7·72 kg cocoons to produce 1 kg raw silk), the Mark 1-F prototypeshowed an average renditta of 7·62. In effect, the field prototype yielded anaverage of over 170 g more silk than the traditional oven for every 100 kg ofcocoons processed. Calculations showed that the gains of obtaining a lowerrenditta could far outweigh the gains from improving fuel efficiency.

During the trial runs, the project team observed that besides improvingproductivity in terms of the quantity of silk produced (renditta), Mark 1-Falso seemed to enhance workers’ productivity in terms of speed. This wasprobably because the gasifier system was able to provide water at moreuniform and consistently high temperatures for cooking than the existingoven. Workers did not have to wait as long for the water in the cookingvessels to boil, nor did they have to change fuelwood feeding rates to

Figure 102Wood cutter installed at

Hindupur


maintain or increase the heat supply to the vessels. Overall, this allowed theworkers to process more cocoons each day.

In order to assess and compare the quality of silk yarn produced by Mark1-F and the existing oven, samples of yarn produced by both ovens were sentto the CSB laboratory at Dharmavaram for analysis. The results showed thatthe Mark 1-F yarn was superior in quality on two counts: size test and wind-ing test. Again, this was probably due to the steady and consistently highwater temperature achieved in the gasifier oven.

Teething problems

Certain problems also surfaced during the Mark 1-F trials at Hindupur. Thecooling chamber—made from used oil drums as a cost-cutting measure—proved inadequate in cooling the ‘raw’ producer gas from the gasifier. Afterjust a few hours of operation, the water temperature in the chamber rose toabove 55 ºC. This reduced the efficiency of gas combustion in the burners. Tosolve the problem, a perforated bottom-plate was incorporated into thechamber. The plate helped break up the stream of incoming hot gas intomany smaller streams, thus increasing the gas–water contact area. This inturn led to greater coolingof the gas, and the watertemperature in this ‘bub-bling chamber’ remained atlow levels even after a fullday’s operation. However, anew problem surfaced—theholes in the perforated platetended to get blocked withtar and particulate matter.To get around this problem,the perforated plate wasreplaced by a flange dif-fuser (Figure 103).

Another problem wasthat the average usefulpower of Mark 1-F’s sixvessels was only about 1.04kWth each. This was muchbelow the desired levels of2.0–2.5 kWth.

Figure 103Gas bubbling chamber with

(a) perforated plate (b) flange diffuser

(a)

(b)

Annexures 235

Besides, the producer gas flow was sometimes weak, resulting in poorburning and consequent blockages of burner ports by tar and particulates. Toimprove the gas flow rate and combustion, the 0.5 HP blower was replacedby a 1 HP kerosene engine blower that was developed by the project teamitself at Gual Pahari. This measure helped increase the useful power pervessel to 1.4 kWth, which was still below the desired level of 2 kWth butadequate to meet the cocoon processing rate of the Kedar unit.

Reelers’ feedback

Reelers provided valuable feedback on Mark 1-F based on their observationsat Hindupur, and later at the first design review workshop held in Bangalore.The reelers made the following important observations/suggestions.� They did not want the pupae dryer at all, despite its good performance.� The gasifier needed electricity to operate its blower, and so a generator set

would be needed to enable it to operate during power outages.� The heat recovery drum should be larger (150–200 litres).� A pipe should be provided to take water directly from the drum to the

cooking as well as reeling basins.� Copper cooking vessels were desirable as they were locally available.

These suggestions helped the project in designing a second field proto-type—Mark 2—for field testing in the Ramanagaram cluster.


FROM F IELD TO COMMERCIAL MODEL

Mark 2: improved field model

As described earlier (see Annexure 3) a field version of the gasifier-based silkreeling oven, Mark 1-F, was tested at Hindupur and reelers were invited towitness the oven’s demonstration runs. Based on the reelers’ feedback at thedesign review workshop held thereafter in March 1996, the project made animproved field model, Mark 2, for trials at selected sites in the Ramanagaramcluster.

Design, fabrication, and installation

The Mark 2 gasifier oven was designed with the following primary objectives:� to increase the useful power level per cooking vessel from the existing

level of 1.4 kWth;� to improve the gas cooling and cleaning system to enable efficient burning

and to reduce maintenance requirements; and� to improve the gas flow by reducing the overall pressure drop across the

system.

The first step was to gather baseline data on the two units selected forfield trials, namely, Pasha’s and Babu’s units. In April 1996, the project teamvisited the Ramanagaram cluster and monitored and gathered data on theoperations of the two units. The data included the amounts of cocoons proc-essed daily, fuel consumption rates, raw silk produced, and useful powerdelivered per cooking vessel. The results are summarized in Table A4-1.

ANNEXURE 4

THE RAMANAGARAM

EXPERIENCE

Annexures 237

The Mark 2 gasifier-based system was designed to meet the followingparameters.� Cocoons processed daily — 80 kg (in two batches of 40 kg

each)� Cocoon processing rate — 10 kg/hour (over an 8-hour

working day)� Total wood consumption — 80 kg� Hopper storage capacity — 40 kg (enough fuelwood for one

batch)� Useful power/cooking vessel — 2.03 kWth

To achieve these parameters, the project team had to make a number ofchanges in the design of Mark 1-F and its sub-components. At the same time,the focus was on reducing costs wherever possible.

A major challenge was to find a suitable blower for Mark 2. In theory, anefficient 0.25 HP blower should have been capable of supplying enough airfor the gasification of fuelwood as well as for combustion of the producergas. However, none of the commercially available centrifugal blowers of 0.25HP capacity met the standards required. Finally, the project opted to use the1 HP kerosene engine blower assembly that it had developed and used withthe Mark 1-F oven at Hindupur.

Another problem was to find a suitable producer gas burner for the Mark2 system. Indeed, this task had posed a major challenge from the very outsetof the project (Box A4-1). Many kinds of burners were designed and tested bythe project team at Gual Pahari during the Mark 0, Mark 1-L, and Mark 1-F

TABLE A4-1Baseline data on existing conventional ovens at

Pasha’s and Babu’s units

Parameter Pasha Babu

Cocoons processed daily (kg) 90 69

Fuel consumed daily (kg) 150–168 146–158

Raw silk produced daily (kg) 10.77–10.78 8.12–8.41

Specific fuel consumption (kg fuel/kg cocoons) 1.6–1.9 2.1–2.3

Useful power per vessel (kWth

) 2.19 2.06


Box A4-1A burning issue: finding

an efficient burner

Six small conventional biogas burn-ers (one for each cooking vessel)were used in the Mark 0 and Mark 1-Lprototype ovens. Similar biogas burn-ers were used in the Mark 1-F oven atHindupur as well. However, the effi-ciency of these biogas burners waslow when burning producer gas(30%–35% at the desired usefulpower level of 2–2.5 kW

th). There

were two main reasons for this: (1)producer gas has a much lower heat-ing value (1000–1200 kcal/Nm3)than biogas (4500 kcal/ Nm3); and(2) producer gas is a mixture of twocombustible gases whose ‘flamespeeds’ differ widely (CO = 0.4 me-tres/sec, H

2 = 2.7 metres/sec).

The project team made many at-tempts to develop a more efficientproducer gas burner. Several burnersof different designs were fabricatedand tested at Gual Pahari. They in-cluded modified biogas burners, pipeburners, and annular pipe burners. Inearly 1996, the project sought the as-sistance of experts from IIP (IndianInstitute of Petroleum), Dehra Dun.An IIP team visited Gual Pahari, stud-ied the gasifier system, and came upwith a few prototype burners thatwere tested in February–March1996. However, in most cases theburner efficiency dropped sharply as

input power was increased; none ofthem achieved efficiencies morethan 30%–35% at the desired usefulpower level.

Later, while designing the Mark 2gasifier oven at Gual Pahari for fieldtrials in the Ramanagaram cluster,the project team developed andtested a porcelain burner with a bedof ceramic beads. This burner yielded40%–45% efficiency. In October1996, an expert from IIT Kanpurcame up with a new burner design.However, by that time the Mark 2field trials were under way atRamanagaram and the priority hadshifted from increasing burner effi-ciency to providing more useful power(that is, increasing the rate of heatsupply to cooking vessels to enablefaster processing of cocoons). Thiswas achieved by replacing four of thesix small biogas burners in the Mark 2oven with larger biogas burners.Thereafter, the gasifier oven’s designitself underwent extensive changes—for instance, the six independentcooking vessels used till then werereplaced by a common water bath di-vided into compartments and heatedby a single burner! Finally, TERI de-signed and developed its own burnerfor the gasifier oven, by modifying thedesign of a standard LPG burner.

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Annexures 239

tests, but the problem of low burner efficiency persisted. Finally, the projectdesigned and developed its own producer gas burner by modifying thedesign of a standard LPG burner.

After finalizing the Mark 2 system’s design, detailed engineering draw-ings were prepared and one system was fabricated, installed, and tested atGual Pahari in May 1996. The system met the performance parameters:fuelwood burning rate was 8–10 kg/hour and the average useful power pervessel was 2–2.3 kWth.

Thereafter, a Bangalore-based fabricator (Jaykay Industries) was providedwith the engineering drawings and asked to manufacture two gasifiersaccording to specifications. Accessories and components such as the burnersets, blower assemblies, sections of pipeline, and so on were procured inDelhi and transported to the Ramanagaram sites. Two sets of cooking ves-sels—each comprising six copper basins—and stainless steel heat recoverydrums were bought from CSTRI, Bangalore. Masonry work was done withthe help of a local mason under TERI’s supervision. In May–June 1996, twoMark 2 systems were fabricated and installed, one each in Pasha’s and Babu’sunits, and trial runs commenced.

Trial runs and results

While the Mark 2 gasifier system performed according to expectations atBabu’s unit, operations at Pasha’s unit were far from smooth. From the veryoutset Pasha complained that Mark 2 was not able to supply his reelers withcooked cocoons at a fast enough rate. The project team soon realized that thiswas not due to any technical fault in Mark 2. Rather, it was because Pashahad suddenly and deliberately increased his rate of production of raw silkyarn (as described in the main text). Pasha was making his reelers workmuch faster than normal; naturally, the reelers were demanding cookedcocoons more quickly from both the existing oven and Mark 2.

To confirm that Pasha had indeed driven up his rate of production, theproject team conducted a fresh study of Pasha’s existing oven. The resultsindicated that the useful power level per cooking vessel had gone up to2.60 kWth—much higher than the earlier level of 2.19 kWth! With the existingoven, increasing the cocoon processing rate posed no problem; it was simplya matter of feeding and burning wood logs at a faster rate in its hearth,because energy efficiency did not matter! However, the Mark 2 system wasdesigned to maximize fuel savings. Any attempt to deviate from the setparameters (such as increasing fuelwood burning rates) would lower the


system’s energy efficiency and negate the very purposes for which the sys-tem had been developed.

To meet Pasha’s persistent demands for higher useful power from Mark 2,the project team procured and tested larger biogas burners at Gual Pahari.Thereafter, four of the existing small burners in Pasha’s Mark 2 system werereplaced by larger burners. Also, a higher-capacity gasifier was designed,fabricated, and tested at Gual Pahari, and Pasha’s Mark 2 gasifier re-mod-elled accordingly. The modified gasifier yielded an average useful power of2.8 kWth per vessel—ample to meet Pasha’s increased demands.

However, the problems did not cease with these changes. The modifiedgasifier burned fuelwood at a much faster rate (12–13 kg/hour). This placedgreater demand for combustion air, which meant that the existing blower inPasha’s unit had to be replaced by a more efficient high-speed blower. WithPasha continuing to complain about the Mark 2 system’s ‘under-perform-ance’, the project team dismantled the entire gasifier oven for critical exami-nation. Tests were also conducted on the quality of wood being burned in theMark 2 during the trial runs. The following facts emerged.� The gasifier’s insulation lining had cracked, and the material itself did not

match that specified in the design documents. The result: lower thermalefficiency.

� The copper cooking vessels bought from CSTRI were larger (8 litres) thanthe 7-litre vessels usually used in conventional ovens. Thus, the vessels inMark 2 held more water and took up more heat than those in the existingovens in both Pasha’s and Babu’s units.

� The fuelwood that was being burned in Mark 2 in Pasha’s unit was of poorquality, with high moisture content (up to 15%) and low calorific value.

In both Pasha’s and Babu’s units, the gasifier lining material was changedand the existing cooking vessels replaced by 7-litre vessels. Steps were alsotaken to reduce the smoke emitted by the gasifier ovens (Boxes A4-2, A4-3).From September 1996 to March 1997, regular comparative tests were con-ducted of the Mark 2 systems against the existing ovens. The results aresummarized below (Figure 104).� Mark 2 brought down specific fuel consumption in both units by around

1.2 kg wood/kg cocoons processed. This translated into a fuel saving of46%.

� In both units, Mark 2 brought about a sizeable reduction in renditta (thatis, it increased silk yield). On an average, an extra 310–370 g of silk wereproduced by Mark 2 for every 100 kg of cocoons processed.

Annexures 241

Figure 104Benefits of gasifier-based system

over conventional oven

conventional oven gasifier-based system


Box A4-2Study of emissionsin silk reeling units

In September 1996, even as theMark 2 trials were under way, theproject undertook a small study ofemission levels in Pasha’s andBabu’s units. The primary source ofpollution in silk reeling units is burn-ing biomass. Hence, the study meas-ured the levels of two pollutants: CO(carbon monoxide) and TSP (totalsuspended particulates). The meas-urements were taken while the con-ventional ovens were in operation.The results showed that CO levels

were 60 times higher than the stand-ards set for residential areas by CPCB(Central Pollution Control Board), and24 times higher than those set for in-dustrial areas. Likewise, TSP levelswere 10 times the limit set for resi-dential areas and four times that setfor industrial areas. It is noteworthythat silk reeling units are generally lo-cated in the midst of residential ar-eas—making the impact of thesepollutants all that more serious.

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Box A4-3Cutting down

the smoke

Workers in both Pasha’s and Babu’sunits voiced a common complaintabout the Mark 2 system: the ovengenerated a lot of smoke that irri-tated the eyes. The project team ex-amined the system while in operationand discovered the source of theproblem. Flue gases escaped fromthe top of the oven’s sliding door,right next to where the workers stoodwhile cooking cocoons—and when-ever combustion was not proper, theflue gases contained a lot of smoke(Figure 105).

Closing the oven door completelydid not work. Although this measureblocked the smoke, it also cut off thesupply of ‘secondary’ air for combus-tion and reduced combustion effi-

ciency. This led to more tar andparticulates being deposited in theburner ports and chimney. To getaround this secondary problem, MSplates were used to seal the sides ofthe oven while leaving a 4-inch gap atthe base of the oven for the entry ofsecondary air. However, now the fluegases proceeded to escape from the4-inch gap! Finally, the gap wassealed off by the sliding door itself; alarge opening was provided in the ov-en’s bottom slab to allow the entry ofair; and the aperture leading to theheat recovery drum was enlarged.With these changes, the producergas burned properly and workerswere no longer troubled by smoke.

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Annexures 243

� With the Mark 2 systems, the average processing rate of cocoons increasedby around 0.8 kg/hour. In other words, it took 41–46 minutes less toprocess a batch of cocoons.

� Samples of the raw silk produced by both Mark 2 and existing ovens weresent to a laboratory at Bangalore for analysis (visual examination, wind-ing tests, size tests and so on) to compare their quality. The tests revealedthat the Mark 2 silk yarn was significantly superior in quality to thatproduced in the existing ovens.

Figure 105Cutting off the smoke from the gasifier oven: (a) original gasifier

oven; (b) first modification in oven; (c) second modification in oven

(a)

(b)

(c)


Technically, Mark 2 had indeed performed well. Yet much work was stillneeded to make an ‘industrial’ model of the gasifier-based oven—a modelthat resolved technical problems existing in Mark 2 while retaining its energyefficiency, and that could be manufactured on an industrial or ‘mass produc-tion’ scale with standardized components.

Mark 3: industrial prototype

To initiate efforts to develop an industrial prototype—Mark 3—two consult-ants were engaged by the project: Prof. Vijay Bapat of IIT Mumbai, andKvaerner Powergas, a reputed engineering and design firm based inMumbai. Both consultants made a number of suggestions that proved invalu-able in re-engineering the complete gasifier system to make it more compactand its many components suitable for large-scale production. The measuresthey suggested included the following:� setting exact standards for each component in terms of parameters such as

material composition, temperature, pressure, flow, and so on to ensuregood quality control and to enable easy manufacture;

� standardization of dimensions to enable easy assembly of parts and better,faster after-sales service;

� stackable components to make them easy to pack and transport;� removable parts (such as burners) to enable easy cleaning/maintenance;� reducing bends and joints in pipes and tubes to enable easier cleaning;

and� user-friendly features.

The project team also met several manufacturers, fabricators, and consult-ants at Mumbai, Delhi, Coimbatore, and Bangalore to gather ideas on how toimprove Mark 2’s design. Some among them had witnessed Mark 1-F inaction at Hindupur and participated in the first design review workshop.Many interesting ideas emerged from the interactions; some are listed below.� The project team was working independently on the concept of using a

single common water bath with a single burner (instead of six separatecooking vessels and burners) so as to reduce the pressure drop in the gaspath. This would enable the use of a smaller capacity blower and in turnreduce electricity consumption.

� Use of a high-efficiency 0.25 HP blower in place of the existing 1 HP blower.� Ways to improve the woodcutter.� Miscellaneous cost-cutting measures.

Annexures 245

A basic problem faced by the Mark 2 system (as well as the Mark 1-Fprototype tested earlier at Hindupur) related to its bubbling chamber. Asdescribed earlier, this was a small tank containing water through which theproducer gas was passed to remove particulate matter before burning. Theproblem was that the hot gas became moist as it bubbled through the waterand its temperature dropped. This reduced the thermal efficiency of thesystem. The pressure of the gas too dropped considerably as it passedthrough the bubbling chamber. This in turn made it all the more necessaryto use a powerful blower to maintain the flow of gas to the burners.The bubbling chamber and blower added to the system’s bulk as well asits costs.

A possible solution was to do away with the bubbling chamber and di-rectly burn the ‘raw’ producer gas. Indeed, this would yield a better thermalefficiency and reduce the loss in gas pressure as well. However, tar andparticulate matter from the raw gas would inevitably get deposited over timeon the insides of the gas pipelines and burner ports, leading to their eventualblockage.

After considerable thought, the project team decided to eliminate thebubbling chamber and the existing narrow GI (galvanized iron) gas pipelineused in Mark 2. Instead, in Mark 3 the producer gas was led directly to theburners through an insulated duct with a large rectangular cross-section. Theinsulation kept the producer gas hot and prevented the condensation of tar;the duct’s large cross-section allowed particulate matter to settle down andalso retained the gas pressure. To make cleaning easier, the duct was pro-vided with a flange on one side. These changes allowed Mark 3 to be oper-ated with a blower of less power

Another major problem with Mark 2 was its sheer size. This made itinconvenient to install and operate in the cramped environment of small-scale reeling units. Based on observations made during field-tests, the projectteam realized that it was possible to reduce the number of cooking vessels inthe oven. This made the Mark 3 system’s design much simpler and trimmeddown its size. In the process, the number of burners needed was reducedfrom six to just one (Box A4-4, Figure 106).

In March 1997, the first Mark 3 system was fabricated by Urjex Boilers,Delhi and installed at TERI’s campus in Gual Pahari for tests (Figure 107).The same month, the second design review workshop was held in Delhi.Several silk reelers who attended the workshop tried out Mark 3 using asmall amount of cocoons brought from Bangalore. Their response was verypositive. In particular, they liked the simplicity and compactness of Mark 3’s


Box A4-4Trimming down

the system

Like the earlier prototypes, the Mark2 system had been designed to re-semble the conventional six-pan cot-tage basin oven. It had six separatecooking basins, each with its ownburner and assorted pipes, valves,and so on. This made the system un-wieldy and difficult to clean.

During field-testing of Mark 2, itwas observed that at any given timeonly four out of the six basins wereused for cooking cocoons; the re-maining two basins were used to sup-ply make-up hot water. This led theproject team to consider the possibil-ity of using a single water bath di-vided into several cooking‘compartments’, instead of separatebasins. The concept was tried out inthe Mark 3 system. The reelers’ re-sponse was very positive, and the de-sign was fine-tuned based on theirfeedback. A single water bath ena-bled uniform temperature of water tobe maintained in all the compart-ments. The use of a single water bathalso reduced the number of burnersrequired from six to just one. Indeed,the common water bath was one of

the most important steps taken to ar-rive at a sleek, integrated design forthe gasifier-based reeling system.

In Mark 1-F as well as in Mark 2,the water in the heat recovery drumdid not reach temperatures above60° C. This was due to inadequateheat transfer from the flue gases tothe drum. To maximize heat recoveryin Mark 3, the oven was sealed com-pletely; the drum was insulated withmineral wool; and instead of a singlepipe as in the earlier versions, sev-eral pipes were provided to carry fluegases around the drum and therebyincrease heat transfer. Also, thedrum was connected to the (common)cooking bath via a float valve, so thatwhenever the water level in the bathdropped (due to evaporation andcarry-over of process water), it wasautomatically compensated by thesupply of hot water from the drum.This not only eliminated the arduoustask of physically transferring hot wa-ter from drum to basin; it also re-duced wastage of water throughspillage.

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design, for this would make its maintenance that much easier. The reelersalso suggested a few more modifications in the system’s design:� reduction in power level of the cooking bath;� lowering the height of the oven to make it easier to work at the cooking

compartments; and� increasing the diameter of the compartments and the space between them.

Annexures 247

Figure 106Schematic drawings showing: (a) Mark 2 system with sixvessels, six burners and bubbling chamber; (b) Mark 3

system with common bath, single burner, largerectangular duct, and without bubbling chamber

(a)

(b)


Accordingly, the 1 HP blower was replaced by a 0.5 HP blower to reducepower levels, and the dimensions and layout of the cooking compartmentswere changed as suggested by the reelers. The Mark 3 system at Gual Pahariwas tested after these modifications. The results showed that a near-uniformtemperature of 92 ºC was achieved in all the cooking compartments. Theexpectation was that this would help in further improving the quality of silkyarn, and in maintaining its uniformity in all the compartments.

Trials and results

In September 1997, an improved Mark 3 system was fabricated by UrjexBoilers and installed in Pasha’s unit for the collection of data. The systemoperated without difficulties, and so in January 1998 a second system (againfabricated by Urjex Boilers) was installed in Babu’s unit. Trials on bothsystems were conducted till September 1998. Both systems performed ex-ceedingly well, as summarized below.� To assess wood saving by Mark 3, about 39 comparative tests were con-

ducted on the system (against the existing cottage basin oven) in Pasha’sunit, and 25 tests in Babu’s unit. The results showed that on average,

Figure 107Industrial prototype Mark 3fabricated by Urjex Boilers

Annexures 249

Mark 3 consumed 0.85 kg wood for every 1 kg of cocoons processed,compared to 2.3 kg wood consumed by the conventional cottage basinovens. In other words, Mark 3 reduced wood consumption by over 60%.

� To assess improvement in silk yield (or reduction in renditta), around 48comparative tests were carried out in Pasha’s unit and 34 in Babu’s unit.The results showed that on an average, Mark 3 produced 370–390 g moresilk than the existing cottage basin oven for every 100 kg of cocoonsprocessed.

� Tests established that the quality of silk produced by Mark 3 was superiorto that produced by existing ovens in both Pasha’s and Babu’s units. TheMark 3 yarn scored better on parameters including average size, sizedeviation, maximum deviation, average cleanness, average neatness,tenacity, elongation, and cohesion.

� A total of 67 comparative tests in both the units revealed that on an aver-age, the cocoon processing rate by the Mark 3 systems was 11%–12%faster than that of the traditional ovens. In effect, an extra 1.05 kg/hour ofcocoons could be cooked using the Mark 3 system.

� Tests showed that Mark 3 reduced water consumption by an average of860 litres for every 100 kg cocoons processed. Unlike the conventionaloven (where hot water for the cooking/reeling basins was supplied manu-ally) the gasifier system’s common cooking basin was automaticallysupplied with hot water from the HRU (heat recovery unit): this reducedthe water loss due to spillage. The common basin’s larger volume alsoreduced water loss during the stirring of cocoons.

� Mark 3 also generated much less smoke and other emissions than tradi-tional ovens.

Mark 4: commercial prototype

In essence, the evolution of the gasifier-based reeling system took place in‘generations’. The models from Mark 0 to Mark 2 represented ‘first-genera-tion’ systems. These models validated gasifier technology; that is, theyshowed that a gasifier-based oven could be used to provide heat to cookcocoons and reel silk, and established the benefits of the technology in termsof fuelwood savings and better silk output/quality.

The Mark 3 models (prototype and improved version) represented the‘second-generation’ systems. These models incorporated changes in the basicdesign of Mark 2 based on field tests and feedback from reelers. The changesincreased the energy efficiency and the product quality to the maximumextent possible; made Mark 3 more compact and suitable for use in actual


field conditions; and also made it more amenable for fabrication in a factory.Thus, with the Mark 3 system the technology had ‘matured’.

The time had come for a ‘third generation’ gasifier-based system: a mar-ketable model that yielded all the benefits of Mark 3 but was more user-friendly and attractive. Thus, Mark 4—the first commercial version of thegasifier-based silk reeling system—was born (Table A4-2).

TABLE A4-2Evolution of the gasifier-based silk reeling oven

System

Mark 0

Mark 1-L

Mark 1-F

New/added features

� Old existing gasifier with

• single nozzle

• option to operate on

updraft/downdraft mode

• single cylindrical struc-

ture for both fire box and

hopper.

� Metallic cocoon cooking

oven with

• six pipe nozzles without

shields

• all-metallic structure.

� Waste heat recovery pu-

pae dryer.

� New downdraft gasifier

with

• two nozzles

• conical hopper above a

cylindrical fire box.


oven with six nozzles

(modified LPG stove

burner).

� Simple cylindrical drum

gas bubbling chamber in-

troduced.

� Mark 1-L (same gasifier

with burner, gas bubbling

chamber tested at Gual

Pahari) shifted to field site

at Hindupur.

Features modified or removed

� Tried cylindrical shield

around gas burners.


oven replaced with masonry

on site at Hindupur; in ef-

fect, the oven is recon-

structed.

� GI sheet shields around gas

burners.

Remarks

� Proof of concept tested out-

side the gasifier shed at Gual

Pahari.

� Demonstrated first to Urs

Heierli of SDC.

� Pierre tested system in sum-

mer of 1995.

� Tested inside new adjacent

gasifier shed at Gual Pahari till

Oct 1995.

� System shifted to Hindupur in

Nov 1995.

� Demonstrated to reelers from

Kanakapura, Ramanagaram.

� Later, gas bubbling chamber is

modified.

� First indications of quality and

renditta improvement emerge

through a few lab tests.

Annexures 251

TABLE A4-2 (Continued)

Mark 2

Mark 3

Mark 4

� Improved gas bubbling

chamber (rectangular with

multiple pass).

� Introduced HRU using cop-

per drum for pre-heating

water, instead of pupae

dryer.

� DG set provided for opera-

tion during power outage.

� Introduction of common

water bath concept (one

big rectangular vessel with

four perforated cooking

vessels placed).

� Single conical burner used

for cooking.

� Specially designed HRU in-

stead of existing copper

vessel.

� Additional burner provided

below HRU for accelerat-

ing water pre-heating proc-

ess during start-up

operation.

� Vessel made from SS in-

stead of copper.

� Commercial version made

by 2M Industries incorporat-

ing inputs from Prof. Bapat

of IIT Mumbai. Emphasis on

user-friendliness, material

optimization, and aesthetic

look.

� Use of SS while minimizing

the incremental cost.

� Small circular compact

ash-pit.

� Light weight ‘HiSil’ insula-

tion inside cooking oven.

� Gasifier design the same; ex-

cept that hopper size is in-

creased by increasing height

to enable wood storage of

60–70 kg instead of 40–

50 kg.

� Blower size increased from

0.25 HP to 0.5 HP with in-

creased rpm using belt pul-

ley mechanism.

� Common gas-carrying duct

below oven instead of two

branches from outside on

both sides.

� Improved gas burner shield.

� HRU design modified. In ear-

lier HRU design, hot flue

gases circulated around cop-

per water drum. Now, HRU

uses gas–water heat ex-

changer (with gas passing

through parallel tubes sur-

rounded by water outside).

� Single gas burner below

common water bath used,

instead of individual modi-

fied biogas burners below all

six cooking vessels.

� Air premixing in gas burner

to enable complete burning

of gas.

� Pre-heated water supplied to

cooking basin through float

valve for maintaining con-

stant water level in cooking

vessels.

� View port provided on the ov-

en’s side to ignite gas in

burner and to monitor flame

in gas burner

� System fabricated in workshop

on Kanakapura road,

Bangalore.

� System first demonstrated at

Pasha’s unit in Ramanagaram

to Urs Heierli in April 1996.

� Later, similar system installed

at Babu’s unit.

� Long-duration field perform-

ance testing and monitoring

carried out in both units for

quantification of benefits.

� This system was fabricated by

Urjex Boilers and demon-

strated for the first time to

reelers in design review work-

shop organized at Delhi in

1997.

� Later, system was shifted to

Pasha’s unit in Ramanagaram.

� Similar system was fabricated

and installed at Babu’s unit.

� This system was marketed.

System New/added features Features modified or removed Remarks


BACKGROUND

The Siddlaghatta silk reeling units use a special kind of vessel known as an‘Italian’ basin to cook cocoons. The Italian basin is almost double the size ofconventional cottage basins in other clusters. Each Italian basin serves co-coons to two reeling basins. The Italian basin and reeling basins are located ina common masonry structure, and the cocoon cookers and reelers stand onopposite sides of the oven or ‘table’ as they work (Figure 108). The silkthreads are wound directly onto reels of standard size (that is, the re-reelingstage is eliminated). Siddlaghatta silk has certain special characteristics suchas stiffness and lower sericin content and fetches a premium in the market.

Siddlaghatta silk owes its superior qualities to the unique layout andoperating practices of the Italian basin units. The project therefore decidedthat in developing a gasifier system for the Siddlaghatta units it would notinterfere in the layout of the Italian basin units, or change the basic design ofthe Italian oven in any way. Instead, it would focus its efforts only on ‘retro-fitting’ the existing Italian oven with a suitable gasifier. Thus, the project’sapproach in Siddlaghatta was driven by the principle of ‘retrofit at low cost’.

In 1998–99, the project team visited the Siddlaghatta cluster and con-ducted detailed energy audits in two units: one owned by B M Gurumurthyand the other by Jnaneshwar. The results confirmed that there was consider-able potential to reduce fuelwood consumption in the Italian basin by the useof gasifier technology (Figure 109). Considering the field conditions—par-ticularly the frequent power failures and the small capacity of average reel-ing units (that is, four Italian basins)—the project decided to develop an

ANNEXURE 5

THE SIDDL AGHATTA

EXPERIENCE

Annexures 253

Figure 108Conventional Italian basin oven:

(a) front view; (b) side view

(a) (b)

Figure 109Sankey diagram showing various

heat streams of Italian oven


updraft gasifier for use with the Italian basin. An updraft gasifier offered themajor advantages listed below.� It could burn relatively larger cut-wood pieces.� It could operate with a relatively low-power blower.� It could even be operated on natural draft mode, that is, without any

electrical power backup.

TECHNOLOGY DEVELOPMENT

Mark 0

In 1999, the project set out to develop an updraft gasifier for use with theItalian basin at TERI’s Gual Pahari campus. In 1996–97, an updraft woodgasifier system had been developed by TERI for large cardamom curing inSikkim. This system became the model for the prototype Siddlaghattaupdraft gasifier.

The first step was to fabricate and test a laboratory prototype—Mark 0.The main purpose of Mark 0 was to confirm that a gasifier system couldprovide the required power level for the Italian basin (that is, the requiredamount of useful heat for cooking cocoons at the rate demanded by reelers).Mark 0 was made up of two cylindrical parts: the lower part was thegasifier ’s main reactor, while the upper part was a hopper that storedenough fuelwood for 3–4 hours’ operation (the time typically taken to proc-ess a batch of cocoons). The tests showed that the Mark 0 gasifier was capa-ble of supplying as much heat as the existing oven: that too, with 30%–40%less consumption of fuelwood.

Mark 0-F

The next step was to design and test a field prototype—Mark 0-F. This modeldiffered from Mark 0 in a number of vital aspects (Figure 110).� Mark 0-F consisted of a single cylinder (in comparison to Mark 0’s two-

cylinder structure); this made it leak-proof and simpler to fabricate.� Mark 0-F had a larger diameter to accommodate fuelwood pieces of larger

size, and to permit a heat-insulation layer of sufficient thickness.� Mark 0-F had a greater vertical distance between the air inlet and pro-

ducer gas outlet. This allowed more ‘residence time’ for the gas andthereby improved the gasifier efficiency.

Annexures 255

Figure 110(a) Mark 0 updraft gasifier for

Italian oven (b) Mark 0-F gasifier

(a)

(b)


� Both conical and square burners were tried out successfully in the Mark 0gasifier to obtain the desired power levels in the Italian basin. However, itwas noticed that the conical burner’s flame was not very stable when thegasifier worked in natural draft mode. Hence, square burners were usedin Mark 0-F.

� Mark 0-F had two air inlet apertures in place of the single aperture inMark 0. The smaller aperture allowed the gasifier to be connected to an airblower, and the larger was meant to allow inflow of air during ‘naturaldraft mode’ operation.

� To make the cleaning of tar and other deposits easier, gas-carrying ductswere provided with a number of flanges that could be opened whenneeded.

Once Mark 0-F’s design and dimensions were finalized, the project pre-pared detailed specifications and engineering drawings of the gasifier and itscomponents (Figure 111). The energy audits had shown that the Siddlaghattaunits were already in the practice of using fuelwood cut into chips of 12–15inches length (300–375 mm) for their Italian ovens. With only a little moresizing, the chips could be used by the gasifier system. Mark 0-F was success-fully tested in Gual Pahari in May 2000.

To ensure smooth conduct of field tests in Siddlaghatta, TERI entered intoformal agreements with the owners of the two units identified for field-tests,namely, Gurumurthy and Anantha Padmanabha. The salient features of theagreements are listed below.� TERI would provide the gasifier and its components (including blower

and burner) and install and commission it. It would also train operators touse the gasifier. Once trained, the reelers were expected to ensure thegasifiers operated regularly for long-distance performance evaluation.

� The reelers had to provide utilities such as power, water, fuelwood (50–75mm in size, moisture content below 15%), space and shelter for the sys-tem, supply of cocoons during tests, operators and other staff during tests,and free access to project personnel for data collection, process monitor-ing, and so on.

Trial runs

In November–December 2000, two updraft gasifier systems were fabricatedby 2M Industries, Mumbai under the guidance of TERI’s technicians. Thesewere transported to Siddlaghatta via Bangalore and installed at the selected

Annexures 257

Figure 111Engineering drawing of Mark 0-F

gasifier assembly


sites. The first system was assembled at Gurumurthy’s unit, and the secondat Anantha Padmanabha’s unit. At this point in time, local supply of cut-wood had still not been arranged for; hence, dry cut-wood pieces werepurchased from a sawmill in Ramanagaram and transported by van toSiddlaghatta.

Trial runs were conducted to check and fine-tune the systems, and toshow the reelers that the gasifiers could actually provide the power (that is,useful heat) demanded by the Italian basins. To start with, the project teamcarried out a few ‘dry’ runs (without any cocoon cooking) to train reelers andoperators in the basic principles of gasifier operation—how to chargefuelwood, ignite the fire, test the producer gas flow, and so on. Operatorswere also taught how to tackle common problems such as blocking of thegrate by ash, unstable flame in the burner due to excess/insufficient airsupply, and blockages caused by over-sized wood pieces.

During the trial runs, the reelers voiced their concern about the excessivesmoke emitted by the gasifier chimney during the start-up period. Theproject addressed the problem by replacing the existing short chimney with ataller, wider chimney that went right through the roof of the unit.

The reelers were also anxious whether the gasifier system could providesufficient power for cocoon cooking, especially in the natural-draft mode.Although each system had a small blower to supply air to the gasifier as wellas to the burner, power outages were frequent and prolonged in Siddlaghatta.To remove the reelers’ anxiety the project team worked out a way to run theblower even during power outages at little additional cost (Box A5-1).

Comparative performance tests started in late-February 2001 and contin-ued till June. There were occasional interruptions in the tests when the unitsclosed down because of the scarcity of good-quality cocoons in the market orbecause of labour problems. In all, data were gathered for 17 days’ opera-tions in Gurumurthy’s unit and 37 days in Anantha Padmanabha’s unit.Analyses showed that the gasifier system reduced fuelwood consumption by38.5%–42.5%, improved the quality of yarn, reduced renditta (that is, in-creased silk yield), and improved the working conditions by reducing smokeand other emissions.

Drying yarn: hot plate–hot air system

In June 2001, SDC and TERI organized a project-cum-design review work-shop at Siddlaghatta during which reelers expressed the need for charcoal todry the silk yarn. Traditionally, they extracted hot charcoal from the ovenand placed it below the reeling shaft to dry the moist yarn as it was reeled,

Annexures 259

Box A5-1Sharing power: the belt–

pulley mechanism

In both Gurumurthy’s and AnathaPadmanabha’s units, the gasifier wasinstalled in a pit in front of the Italianbasin table so that the gas outletemerged at ground level. This allowedthe hot producer gas and air to risenaturally to the burner placed belowthe cooking vessels, enabling thegasifier to function without the use ofa blower (Figure 112). However, thereelers remained worried about thesystem’s ability to deliver gas and airat a fast enough rate (that is, suffi-cient heating power) in this ‘natural-draft’ mode. To allay theirapprehensions, the project teamworked out a way to run the blowereven in the absence of mains power—by drawing mechanical power fromthe reeling shaft!

Each unit had a small kerosene en-gine that was used to turn the reeling

shaft during power outages. Some-times, the shaft was turned manually.The gasifier’s blower could operatewith low power. The project thereforedevised a ‘belt–pulley mechanism’ bywhich the mechanical power of theturning shaft could be used to run theblower if and when necessary (Figure113). Kerosene consumption did in-crease slightly due to the increasedload of the blower on the engine; butthe increase was barely 10% (from440 ml/hour to 486 ml/hour). Thismade the belt–pulley mechanism afar cheaper option than installing anadditional generator set to run theblower. It also assured the reelersthat they could run the gasifier sys-tem uninterruptedly and at optimumcapacity even during power outages.

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Figure 112Gasifier installation in apit at Gurumurthy’s unit


Figure 113Belt–pulley arrangement for blower

in Italian oven gasifier system

but the gasifier system producedlittle or no charcoal. The projectteam decided to modify the gasifiersystem so that heat from the fluegases could be used to dry the moistsilk yarn.

Two systems were tried out, firstat Gual Pahari and then atGurumurthy’s unit. In the ‘hotair ’system, fresh air was passedthrough insulated pipes surroundingthe chimney. The air picked up heatfrom the flue gases in the chimneyand was then passed through ductsbelow the reeling shaft to dry theyarn. In the ‘hot plate’ system, hotflue gases were directly led alonginsulated pipes through an annularplate placed below the reeling shaft.The plate became hot and its radiantheat dried the yarn.

In October 2001, reelers’ feedbackwas sought on the two yarn-dryingsystems. The reelers made twoimportant observations:� higher temperature levels were

needed for the drying systems tobe effective during winter and inthe rainy season; and

� to achieve higher temperatures,the project should try to combinethe two systems, that is, todevelop a ‘hot plate–hot air’system.

Based on these suggestions, theproject successfully developed a hotplate–hot air system and installed itat Gurumurthy’s unit (Figure 114).

Figure 114Combined hot plate–hot airsystem at Gurumurthy’s unit

BIBLIOGRAPHY

Albu M. 1997Technological learning and innovation in industrial clusters in the South, Paper No. 7Brighton: Science Policy Research Unit, University of Sussex

Dadhich P K and Mande S. 1994Innovative financing schemes for biomass-based cogeneration plantsEnergy Environment Monitor, March 1994

Debyani G, Sagar A, and Kishore V V N. 2005Scaling up biomass gasifier use in different application categories: suggestions forinterventionsEnergy Policy 33(1): 1367–1372

Dhingra S, Mande S, Kishore V V N, Joshi V. 1996Briquetting of biomass in India: status and potentialIn Proceedings of the International Workshop on Biomass Briquetting, Indian Institute ofTechnology, Delhi, edited by P D Grover and S K Mishra, Food and AgricultureOrganization of the United Nations, Bangkok, RWEDP Report No. 23, pp. 24–30

Dhingra S, Mande S, Kishore V V N, Joshi V. 1996Financial appraisal of briquetting plantsIn Proceedings of the International Workshop on Biomass Briquetting, Indian Institute ofTechnology, Delhi, edited by P D Grover and S K Mishra, Food and AgricultureOrganization of the United Nations, Bangkok, RWEDP Report No. 23, pp. 159–169

Dhingra S and Kishore V V N. 2001SDC–TERI experience on product development—Case 1: design, development, andfield-testing of gasifier-based silk reeling ovenIn Renewables: products and markets, proceedings of Renewable 21 Internationalconference, 16–17 February 2000, New Delhi, The Energy and Resources InstituteNew Delhi: The Energy and Resources Institute, pp. 38–46


Dhingra S, Mande S, Raman P, Srinivas S N, Kishore V V N. 2004Technology intervention to improve the energy efficiency and productivity of silkreeling sectorBiomass and Bioenergy 26(2004): 195–203

Ghosh D, Sagar A, and Kishore V V N. 2004Scaling up biomass gasifier use: applications, barriers, and interventions[Paper No. 103, Environment Department Papers, Climate Change Series]Washington, DC: The World Bank. 108 pp.

Gulati M. 1997Restructuring & Modernization of SME (Small & Medium Enterprise) Clusters inIndiaNew Delhi: United Nations Industrial Development Organization

Heierli U. 2000Poverty alleviation as a business: the market creation approach to developmentBerne: Swiss Agency for Development and Cooperation. 111 pp.

Kishore V V N and Rastogi S K. 1987Thermal analysis of cardamom curing chambersEnergy in Agriculture 6(1987): 245–253

Kishore V V N. 1989Economics of wood gasifier systems for irrigation pumpingIndian Journal of Agriculture Economy 44(1), January–March 1989

Kishore V V N and Murthy V L N. 1989A review of design procedure for downdraft gasifiersIn Renewable energy for rural development, proceedings of National Solar EnergyConvention, 1989, HyderabadNew Delhi: Tata McGraw-Hill

Kishore V V N, Raman P, and Mande S. 1995Gasification of industrial biomass waste: case studies for herbal waste andtobacco dust, 193–202 pp.Renewable Energy Utilization: scope, economics and perspectivesNew Delhi: Tata Energy Research Institute

Kishore V V N and Srinivas S N. 2003Biofuels of IndiaJournal of Scientific & Industrial Research 62, January–February 2003: 106–123

Kishore V V N, Bhandari P, and Gupta P. 2004Biomass energy technologies for rural infrastructure and village power:opportunities and challenges in the context of global climate change concernsEnergy Policy 32(2004): 801–810

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Kohli S, Raman P, and Kishore V V N. 1988Evaluation of various fuels for gasificationIn Energy options for the ’90sNew Delhi: Tata McGraw-Hill

Mande S and Kishore V V N. 1997Tea industry: technological options for combined heat and power systemsIn Cogeneration, Policies, Potential, and TechnologiesNew Delhi: Tata Energy Research Institute, pp. 163–168

Mande S. 1999Putting colour back into large-cardamomWood Energy News 14(1): 12 pp.

Mande S, Kumar A, and Kishore V V N. 1999A study of large cardamom curing chambers in SikkimBiomass and Bioenergy 16(6): 463–473

Mande S, Lata K, and Kishore V V N. 1999Studies on quality improvement of large-cardamom using an advanced gasifierbased dryer, pp. 372–365In Renewable Energy for Sustainable Development, proceedings of NREC (NationalRenewable Energy Convention), 1999Indore: Solar Energy Society of India

Mande S, Pai B R, and Kishore V V N. 2000Study of stoves used in silk reeling industryBiomass and Bioenergy, 19(1): 51–61

Mande S. 2001Cardamom curing industry (large), pp. 112–114In Asia Industrial and Institutional Stove CompendiumBangkok: Asia Regional Cookstove Program of FAO-RWEDP

Mande S. 2001Cardamom curing industry (small), pp. 115–116In Asia Industrial and Institutional Stove CompendiumBangkok: Asia Regional Cookstove Program of FAO-RWEDP

Mande S. 2001Charka silk reeling industry, pp. 117–119In Asia Industrial and Institutional Stove CompendiumBangkok: Asia Regional Cookstove Program of FAO-RWEDP


Mande S. 2001Silk reeling industry, pp. 120-122In Asia Industrial and Institutional Stove CompendiumBanglok: Asia Regional Cookstove Program of FAO-RWEDP

Mande S and Kishore V V N. 2001Biomass gasifier systems for sustainable development of rural India, pp. 126–136[Proceedings of National Workshop on Renewable energy and Energy ConservationAwareness and Strategies, 15–17 December 2001, Coimbatore]Chennai: Regional office MNES

Mande S and Kishore V V N. 2001SDC–TERI experience on product development—Case 2: development of simple,low-cost, appropriate gasifier system for large cardamom drying in Sikkim,pp. 47–58In Renewables: products and markets, proceedings of Renewable 21 Internationalconference, 16–17 February 2000, New Delhi, organized by The Energy andResources InstituteNew Delhi: The Energy and Resources Institute

Mande S and Kishore V V N. 2001Wood gasifier system for large-scale cookingIn Proceedings of International Workshop on Biomass Fuels and Combustion Systems(BFCS-2000), 20–24 November 2000, Pune

Mande S, Lata K, and Kishore V V N. 2001Biomass gasifier based crematorium: an efficient and eco-friendly way of cremation,pp. 316–320In Renewable Energy Technologies for New Millennium, proceedings of NREC-2000,20–22 December 2000, Mumbai, organized by Solar Energy Society of India

Mande S, Pai B R, and Kishore V V N. 2001Study of stoves used in silk reeling industry, pp. 1–31In Asia Industrial and Institutional Stove CompendiumBangkok: Asia Regional Cookstove Program of FAO-RWEDP

Mande S and Kishore V V N. 2002Applications of biomass gasifier systems: potential and prospects, pp. 85–95In Renewable Energy Science Series XI: practising renewable energy options—the cleaninitiatives, edited by P RadhakrishnaChennai: Regional office MNES

Mande S and Kishore V V N. 2004Eco-friendly and energy-efficient green brick drying[Proceedings of Third Asia Pacific Drying Conference, 1–3 September 2003]Bangkok: Asian Institute of Technology

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Mande S. 2005Biomass gasifier systems for decentralized rural applications, pp. 132–144[Proceedings of UTTHAN-2005: seminar on sustainable development technologyinitiatives for the development of Rural Masses, 18–20 February 2005, organized byCTSD (Centre of Technology for Sustainable Development)Faridabad: CTSD

Mande S and Lata K. 2005Potential of converting phumdi waste of Loktak Lake into briquettes for fodderand fuel use, pp. 100–108In Aquatic Weeds: problems, control, and management, edited by S M Mathur,A N Mathur, R K Trivedi, Y C Bhat, P MohonotNew Delhi: Himanshu Publications

Raman P, Sharma S D, and Kishore V V N. 1989Studies on a briquetting gasification system for utilization of biomass residuesIn Proceedings of the first National Meet on Recent Advances in Biomass GasificationTechnology, Indian Institute of Technology, 61 pp.

Raman P, Sharma S D, Kohli S, Kishore V V N. 1989Design and test performance of a throatless downdraft gasifier with a low specificgasification rateIn Renewable energy for rural development, proceedings of National Solar EnergyConvention 1989, HyderabadNew Delhi: Tata McGraw-Hill

Raman P, Dhingra S, and Kishore V V N. 1990A multifuel, multipurpose, prototype, biomass gasification system: design andperformance details, pp. 99–119In Proceedings of the Second National Technical Meet on Recent Advances in BiomassGasification Technology, Udaipur

Raman P, Mande S, and Kishore V V N. 1993Multifuel, multipurpose biomass gasifier system to meet rural energy needs andto promote rural industriesUrjabharti 3(3), 1993


Raman P, Vakil J, and Kishore V V N. 2004Use of a large biomass gasifier system for a chemical industry: case study for pro-duction of magnesium chloride[Proceedings of Industrial Applications of Biomass Gasification Technology forEnergy Auditors and Consultants, 7 June 2004, Indore, organized by DAV]Indore: DAV

Rao V G, Mande S, and Kishore V V N. 2001Study of drying characteristics of large-cardamomBiomass & Bioenergy 20(1): 37–43

Sharma S D, Raman P, and Kishore V V N. 1989Standardization of an apparatus for the estimation of tar, particulate, andmoisture contents in produce gasIn Proceedings of the First National meet on Recent Advances in Biomass GasificationTechnology, Indian Institute of Technology, Bombay, p. 198

Sinha C S and Kishore V V N. 1991Biofuel conversion processes and technologiesTIDE 1(1): 1–24

Srinivas S N. 2000Biomass consumption in unorganized enterprises in IndiaBUN Newsletter 3(3), June 2000

Srinivas S N, Raman P, Dhingra S, Kulkarni V B, Setty H H N, Kishore V V N. 2004Performance of gasifier systems in silk dyeing industrySESI Journal 14(1): 1–17

Srinivas S N, Ninga Setty H H, Kulkarni V B, Mande S, Kishore V V N. 2004Potential for energy conservation measures in puffed rice industry[Proceedings of 26th National Energy Convention of Solar Energy Society of Indiaand International Conference on New Millennium: alternative energy solutions forsustainable development, 17–19 January 2003, Coimbatore, organized by SESI (SolarEnergy Society of India)Coimbatore: SESI, pp. 549–554

TERI (Tata Energy Research Institute). 1992Design, fabrication, testing, and field demonstration of energy-efficient dryer forsome cash crops[Submitted to DST (Department of Science and Technology]New Delhi: TERI

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TERI (Tata Energy Research Institute). 1992Potential for utilization of biomass gasifier system in plantation and relatedindustries[Submitted to MNES (Ministry of Non-conventional Energy Sources)]New Delhi: TERI

TERI (Tata Energy Research Institute). 1995Study of ovens in silk reeling units[Submitted to Swiss Agency for Development and Cooperation]TERI Project Report No.1995IE53

TERI (Tata Energy Research Institute). 1996Study of cardamom curing chambers in Sikkim for energy efficiency and technologyupgradation[Submitted to Swiss Agency for Development and Cooperation, Bangalore]TERI Project Report No. 1995RT53

TERI (Tata Energy Research Institute). 1997Retrofitting of cottage basin ovens used in silk reeling industry[Submitted to Swiss Agency for Development and Cooperation]TERI project report No. 1993IE56

TERI (Tata Energy Research Institute). 1997Development of gasifier-based silk reeling oven[Submitted to Swiss Agency for Development and Cooperation]Project report No. 1995RT52

TERI (Tata Energy Research Institute). 1997Development of wood-gas-based silk reeling oven[Submitted to Swiss Agency for Development and Cooperation]Phase 2: TERI Project report No. 1996RT51

TERI (Tata Energy Research Institute). 1998Action research phase development of gasifier system for large-cardamom dryingin Sikkim[Submitted to Indo-Swiss Project Sikkim, Gangtok]TERI Project Report No. 1996RT52

TERI (Tata Energy Research Institute). 1998Developing and field-testing industrial prototype of wood-gasifier-based silkreeling oven and other related activities[Submitted to Swiss Agency for Development and Cooperation]TERI Project Report No. 1997BE51


TERI (Tata Energy Research Institute). 1998Energy conservation in small and micro enterprises: an action research plan[Proceedings of the Screening Workshop, 8–9 December 1994, New Delhi, edited byV Joshi, P Jaboyedoff, N S Prasad, and N Vasudevan]New Delhi: Tata Energy Research Institute. 187 pp.

TERI (Tata Energy Research Institute). 1999Pilot Phase: development of gasifier system for large cardamom drying in Sikkim[Submitted to Indo-Swiss Project Sikkim, Gangtok]TERI Project Report No. 1998BE41

TERI (Tata Energy Research Institute). 2000Rural energy matters: the Dhanawas experienceNew Delhi: TERI. 190 pp.

TERI (Tata Energy Research Institute). 2000Action research for commercialization of gasifier system for silk industry: Phase 2[Submitted to Swiss Agency for Development and Cooperation]TERI Project report No. 1998BE42

TERI (Tata Energy Research Institute). 2000Pre-project survey of most commonly used silk rearing houses in Karnataka[Submitted to Swiss Agency for Development and Cooperation, Bangalore]TERI Project Report No. 1998BE43

TERI (Tata Energy Research Institute). 2000Programme for popularizing gasifier for large cardamom drying in Sikkim[Submitted to Indo-Swiss Project Sikkim, Gangtok]TERI Project Report No. 1999BE43

TERI (Tata Energy Research Institute). 2000Action research for commercialization of gasifier systems for silk industry: Phase 3[Submitted to Swiss Agency for Development and Cooperation]TERI Project report No. 2000BE41

TERI (Tata Energy Research Institute). 2001Field testing of gasifier-based Italian oven (Siddlaghatta cottage basin) prototype[Submitted to SERI 2000, Bangalore]TERI Project report No. 2000BE42

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TERI (Tata Energy Research Institute). 2002Development of improved gasifier-based Italian (Siddlaghatta cottage basin) oven[Submitted to SERI 2000, Bangalore]TERI Project Report No. 2001BE42

TERI (Tata Energy Research Institute). 2002Development of gasifier-based crematorium[Submitted to Ministry of Non-conventional Energy Sources, Government of India,New Delhi]TERI Project report No. 1999BE63

TERI (The Energy and Resources Institute). 2003Development of commercial gasifier for Siddlaghatta cottage basin oven[Submitted to SERI 2000, Bangalore]TERI Project Report No. 2002BE41

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TERI (The Energy and Resources Institute). 2004Potential assessment of biomass gasifier for various applications in northeasternstates[Submitted to Ministry of Non-conventional Energy Sources]TERI Project Report No. 2002BE61

TERI (The Energy and Resources Institute). 2004Policy research on promotion and adoption of efficient biomass technologies inrural/small industries[Submitted to Swiss Agency for Development and Cooperation]TERI Project Report No. 2000BE44

CONTRIBUTORS

Apart from the main contributors named earlier in the Thermal GasifiersTeam, the following is a list of people who have made substantial contribu-tions to the success of the interventions in various capacities and at differentstages. This list is not comprehensive. There are several others who havehelped in the intervention over the years.

Tina AlwadiTERINew Delhi

D Balakrishna AryaSilkTex IndustriesKanakpura

Sukhindra Rao BabuReelerRamanagaram

T M BabyconPioneer Magnesia WorksKharagoda

Sameeulla BaigReelerSiddlaghatta

Vijay BapatIDC-IITMumbai

Jahangir BashaReelerCheyur-Coimbatore

Sangeeta BasmatkarRangsangat Kala KendraNew Delhi

C P BasnetDoHGangtok

Prem BasnettDoHPakyong

S S BawaMNESNew Delhi

P BhutiaDoAGangtok

Uchung BhutiaDoHGangtok

Nima BhutiaDoHGangtok

K BhutiaDoHGangtok

K T BhutiaDoHGangtok

P C BhutiaDoHGeyzing

Kachung BhutiaFarmerKabi

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Lakchung BhutiaFarmerThingchim-Mangan

Topgay BhutiaFarmerWest Sikkim

P T BhutiaFarmerTemi Tarku

Robert CarterIDEColorado, USA

Padma ChandarTERIBangalore

Sunil ChandraChanderpur WorksYamunanagar

Sudhir ChandraChanderpur WorksYamunanagar

B ChannaveerappaTERIBangalore

P ChakravartyTERIBangalore

Sunita ChaudhrySDCNew Delhi

S B ChhayaNSMAmbernath

J K ChhetriDoHGangtok

Naveen Chandra ChhetryDoHNamthang

R M CursetjiACCThane

Tenzing DadulDoHMangan

Tenzing DadulEx-MLALingza Dzongu-Mangan

Sonam DadulFarmerDzongu-Mangan

Rudolf DanneckerSDCNew Delhi

Isabella DasSadhanaDharwad

S K DasguptaKvaerner Powergas India

LtdMumbai

Poonam DeveshwarTERINew Delhi

S DevrajNishant ArchitectBangalore

K J DineshTIDEBangalore

Niki DomaDoHGangtok

Jean Pierre DuboisSDCBern

K P EashwarTERINew Delhi

Charles GeigerSDCBangalore

G GirigowdaReelerKankpura

Anil GodboleNSMAmbernath

Rajeev GoswamiPrime Horti-agro Projects

LtdNew Delhi

Debashish GoswamiTERINew Delhi

Narendra GoyalChandpur Shamshanghat

Vikas SamitySundernagar

Ashok GroverSteam-O-TechVasai

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Contributors 273

Ajit GuptaMNESNew Delhi

P R B GupthaTERIBangalore

Navraj GurrungISPSGangtok

B M GurumurthyReelerSiddlaghatta

G K GurungDoHGangtok

I B GurungFarmerKaluk-West Sikkim

Dambarsing GurungFarmerWest Sikkim

Karma GyatsenFarmerNaga-Mangan

Rukhmani HaldeaMinistry of TextilesNew Delhi

Nandita HazarikaTERIGuwahati

Udo HoeggelISPSGangtok

JaganathA P Dyeing UnitBangalore

Shradha JaiswalTERINew Delhi

C K JalajakshiTERIBangalore

M S JnaneshwarReelerSiddlaghatta

Sincy JosephTERIBangalore

E JosephTERINew Delhi

Yateendra JoshiTERINew Delhi

R K JoshiTERINew Delhi

S JyothiTERIBangalore

J S KamathJaya BoilersCoimbatore

C T KaxyFarmerMangan-North Sikkim

Topgay KaziFarmerMalling-Mangan

Pentook KaziFarmerLantay Khola-Mangan

C T KaziFarmerMalling-Mangan

R KeshvanDoS Tamil NaduChennai

Vijay KhareNSMAmbernath

K L KrishnamurthyTSC, ReelingSiddlaghatta

Mohan Kulkarni2M IndustriesMumbai

Prabhakar Kulkarni2M IndustriesMumbai

Sharvan KumarReelerDharampuri

Anil KumarTERINew Delhi

Rajani KumariTERINew Delhi

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K P P KurupISPSGangtok

John KuttySpices BoardGangtok

Tenzing Dadul LachenpaDoHGangtok

Zigmi LachenpaFarmerDzongu-Mangan

S LamaDoHGangtok

B B LamaDoHGangtok

V L LamaniDoS KarnatakaSiddlaghatta

Tashi LamhoFarmerMangan

Chhoden LepchaFarmerDzongu-Mangan

Chumsy LepchaFarmerDzongu-Mangan

Ongdup LepchaFarmerDzongu-Mangan

Tashi LhamoFarmerNaga-Mangan

S S LokrasASTRA, IIScBangalore

Ritu LuthraTERINew Delhi

H K MadanIIPDehra Dun

D MahadevappaSERI-2000Bangalore

S D MazumdarACCThane

D P MishraIITKanpur

D K MukhiaDoHGangtok

Herman MulderSDCBangalore

Janardhana MurthyTSC-ReelingSiddlaghatta

S P MuthuramanHi-Tech EngineersCoimbatore

R G NadadurDoS KarnatakaBangalore

A M NagarajaBIETDavangere

T S NagarajaSERI-2000Bangalore

Shobha NagendraTERIBangalore

G S NairSDCNew Delhi

P G NangpaFarmerLingza Dzongu-Mangan

Zigmi OngdaFarmerAmbithang-Mangan

Anantha PadmanabhaReelerSiddlaghatta

B R PaiTERIBangalore

R M PallanaOutreachBangalore

Ugen PalzorFarmerRavang Khola-Mangan

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Contributors 275

B L ParthasarathySERI-2000Bangalore

Mohib PashaReelerRamanagaram

Ganesh Patel2M IndustriesMumbai

R P PatelJacob H&GNew Delhi

Matthew PhillipGreenergy SystemsBangalore

Paul PollackIDEColorado, USA

PrabhakarDoS Andhra PradeshHyderabad

H R PradhanDoHGangtok

Y K PradhanDoHGangtok

L N PradhanDoHNamthang

M K PradhanDoHNamthang

Rajendra PrasadKedar Silk Reeling UnitHindupur

Kiran PrasadSDCBangalore

K K PuriRadha Soami SatsangBeas

Sandeep RahejaIITKharagpur

Ambiraman RaiFarmerAssam Lingzay

Dhanraj RaiFarmerAssam Lingzay

Panch Bahadur RaiFarmerAssam Lingzay

Bhawani Prasad RaiFarmerDalapchen Rongli-East

Sikkim

Jas Bahadur RaiFarmerManiram-Namthang

Y S RajanCIINew Delhi

Kumar RajeshTERINew Delhi

K V RajeshwariTERINew Delhi

R RajgopalVivek Colour FactoryBangalore

S C RajsekharSymbiotec Research

AssociatesBangalore

I J RajuI J Raju & AssociatesNew Delhi

T RamachandranPSG College of

TechnologyCoimbatore

S RameshaTERIBangaore

H L Krishnamurthy RaoRaghvendra ConsultantsSiddlaghatta

V G RaoIITMumbai

Usha RaoI J Raju & AssociatesNew Delhi

Sheshagiri RaoReelerKankpura

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A K RastogiJawaharlal Nehru

UniversityNew Delhi

N RaviVijay Engineering

EnterprisesBangalore

Lakshmipathy ReddyDoS KarnatakaKolar

N Srinivasalu ReddyDoS Andhra PradeshHindupur

Thendup RiponFarmerThingchim-Mangan

M P RoyUrjex BoilersMeerut

Sunil SahsrabhudheyConsultantVaranasi

S A SampathkumarNewfield EngineersBangalore

S K SaxenaKvaerner Powergas India

LtdMumbai

Jagnarayan SharmaFigu Engineering WorksRanipool-East Sikkim

R D SharmaMNESNew Delhi

Rakesh SharmaShambhavi AgencyNew Delhi

Kamal SharmaTERINew Delhi

K ShivanandaGreenergy SystemsBangalore

Amarjeet SinghChandpur Shamshanghat

Vikas SamitySundernagar

Archana SinghTERINew Delhi

T H SomashekarCSTRIBangalore

R K SoodHPFSRPShimla

S SridharInfocus Research & Field

Services Pvt LtdNew Delhi

R SrinivasanDoS KarnatakaBangalore

J R SubbaDoHGangtok

C SurendranTERINew Delhi

Jatinder Nath SwainDoS Tamil NaduChennai

Arul SwamiOutreachBangalore

Wangyal TadenFarmerWest Sikkim

Topchen TakrapaDoHRavangala-South Sikkim

A TarnutzerISPSGangtok

Pemza TenzingAILCGAMalling-Mangan

P G TenzingDept of IndustriesGangtok

P G TenzingFarmerPentok-Mangan

S W TenzingGovernment of SikkimGangtok

D TewariDoAGangtok

Hetram ThakurParivartanSanjauli-Shimla

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Contributors 277

Ongay TopdenFarmerRavangala-South Sikkim

Dinesh TorgalConsultantBangalore

Mark TsheringFarmerRavang Khola-Mangan

P P VajifdarACCThane

Jehangir VakilPioneer Magnesia WorksAhmedabad

S VaradrasanSpices BoardGangtok

U VellaikannuTERINew Delhi

Kavita VermaTERINew Delhi

K R VishwanathanSDCNew Delhi

VishwanathShilpa Silk PrintsBangalore

S B VijayaraghavanAltech IndustriesCoimbatore

Kurt VoegeleSDCNew Delhi

Ariane WaldvogelSDCNew Delhi

Arvind WalekarAMCAmbernath

Werner HunzikerSDCBerne

Greg WishartAshton Court Consultants

LtdLondon, UK

R P YadavL S Davar & CompanyNew Delhi

Karma YezorDoHMangan

Karma ZongtenpaFarmerMangan

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ACC Associated Cement Companies LtdAILCGA All India Large Cardamom Growers AssociationAMC Ambernath Municipal CorporationAPITCO Andhra Pradesh Industrial and Technical Consultancy

OrganizationBIET Bapuji Institute of Engineering and TechnologyBIMST-EC Bangladesh, India, Myanmar, Sri Lanka, Thailand—Economic

CooperationCFC chlorofluorocarbonCII Confederation of Indian IndustryCSB Central Silk BoardCSRTI Central Sericultural Research and Training InstituteCSTRI Central Silk Technological Research InstituteDA Development AlternativesDNES Department of Non-conventional Energy SourcesDoA Department of AgricultureDoH Department of HorticultureDoS Department of SericultureDST Department of Science and TechnologyESCO Energy Services CompanyFAO Food and Agriculture OrganizationGAP Ganga Action PlanGHG Greenhouse GasGI Galvanized IronHID Human and Institutional DevelopmentHPFSRP Himachal Pradesh Forest Sector Reform Project

ABBREVIATIONS


HRU Heat Recovery UnitIDC Industrial Design CentreIDE International Development EnterpriseIISc Indian Institute of ScienceIIT Indian Institute of TechnologyISPS Indo-Swiss Project SikkimKSFC Karnataka State Financial CorporationLDO Light Diesel OilLPG Liquefied Petroleum GasMNES Ministry of Non-conventional Energy SourcesMNRE Ministry of New and Renewable EnergyMS Mild SteelNABARD National Bank for Agriculture and Rural DevelopmentNEPED Nagaland Environmental Protection and Economic

Development through People’s ActionNGO Non-Governmental OrganizationNSM Nagarik Sewa MandalNSSP National Silkworm Seed ProjectPAU Punjab Agricultural UniversityPMW Pioneer Magnesia WorksRCC Reinforced Cement ConcreteRNR-RC Renewable Natural Resources—Research Centre, JakarSDC Swiss Agency for Development and CooperationSIDBI Small Industries Development Bank of IndiaSMiE small and Micro EnterprisesSPRERI Sardar Patel Renewable Energy Research InstituteSS Stainless SteelTERI The Energy and Resources InstituteTIDE Technology Informatics Design EndeavourUNEP United Nations Environment ProgramUNFCCC United Nations Framework Convention on Climate ChangeUNIDO United Nations Industrial Development OrganizationVEE Vijay Engineering Enterprises

Documents

Towards Cleaner Technologies - bookstore.teri.res.inbookstore.teri.res.in/docs/books/SDC-Gasifier full.pdf · Towards Cleaner Technologies: a process story on biomass gasifiers for