LEMBAGA MINYAK SAWIT MALAYSIA …palmoilis.mpob.gov.my/publications/POEB/poeb91.pdfPALM OIL ENGINEERING BULLETIN NO. 91 ISSUE NO. 91 (April - June 2009) LEMBAGA MINYAK SAWIT MALAYSIA

PALM OIL ENGINEERING BULLETIN NO. 91 �

ISSUE NO. 91 (April - June 2009)

LEMBAGA MINYAK SAWIT MALAYSIAMALAYSIAN PALM OIL BOARD

KEMENTERIAN PERUSAHAAN PERLADANGAN DAN KOMODITI MALAYSIAMINISTRY OF PLANTATION INDUSTRIES AND COMMODITIES, MALAYSIA

Website: www.mpob.gov.my


CONTENTS

Editorial

RECENT EVENTS

FORTHCOMING EVENTS 2009 MPOB Training Programme

2009 MPOB Conferences/Seminars

FEATURE ARTICLESPalm Waste as Alternative Fuel for CementPlant

How to Fix Price for Your Biomass

Codes of Practice (CoP) - What it Means forMillers?

Vynke’s Renewable Energy Steam Power Plants

Mongana Basics: Part 17 - Oxidation of Oil

MILLING DIALOGUE

DATASHEET CDM Status in Malaysia

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3

9

10

13

EDITORIAL BOARD

ChairmanDatuk Dr Mohd Basri Wahid

• Datuk Dr Choo Yuen May• Dr Lim Weng Soon• Dr Ma Ah Ngan

• Ab Aziz Md Yusof • Ir N P Thorairaj

SecretaryIr N Ravi Menon

Malaysian Palm Oil BoardMinistry of Plantation Industries and Commodities,

MalaysiaP. O. Box 10620, 50720 Kuala Lumpur, Malaysia

Tel: 603-8769 4400Fax: 603-8925 9446

Website: www.mpob.gov.my

© Malaysian Palm Oil Board, 2009All rights reserved.

No part of this publication may be reproduced, stored in a retrieval system, in any form or by any means, electronic,

mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.

Products and services advertised in thisPalm Oil Engineering Bulletin do not

connote endorsement by MPOB.

TEditorial

see page 2

23

27

19

31

45

he other day a representive from the cement industry asked me during a meeting at

the Ministry of Energy, Green Technol-ogy and Water, about what steps are being taken by MPOB to prevent the surplus biomass from the industry be-ing exported to overseas markets. I was getting a little nervous about what an-swer to offer, when the chairperson re-torted that every commodity is subject to the law of demand and supply. She said that if the cement industry is will-ing to pay the same rate as the foreign merchants, they also can procure the biomass.

During the last few years, the cement industry had been using oil palm biomass at a bargain price, probably at RM 3 for empty fruit bunches and kernel shell between RM 80 – RM 120 t-1. Considering that kernel shell has a calorific value of almost half that of good grade coal, 2 t of kernel shell can replace 1 t of coal. This means that the cement factories could get coal at about RM 240 t-1, when equated in terms of heat values. This is a good bargain but the palm oil mills are not legally bound to sell their biomass by-products only to the cement factories, unless they are willing to offer attractive prices. Millers cannot be blamed for selling their products to the highest bidder in this case foreigners, unless they are bound by some kind of agreement. This problem can be resolved through a meaningful dialogue involving interested parties.

We have seen the medium-sized fac-tories in Malaysia, which use steam for processing like noodle factories, glove factories and others who replaced their

43

PALM OIL ENGINEERING BULLETIN NO. 91�

from page 1

CALL FOR ARTICLES

The millers are requested to send in articles of relevance to the palm oil industry in Malaysia for publication in Palm Oil Engineering Bulletin. By sharing your expertise you will be helping the industry and the nation as a whole. The topics of interest are:

1. Plant modifications done in your mill that resulted in improvements in milling operation or maintenance.

2. Innovations done in your mill that produced improvements in the operation of the mill and that you are willing to share them with others.

3. Any special work done in your mill that directly resulted in improvements in OER and product quality.

Please submit your article to us and we shall be pleased to publish them in Palm Oil Engineering Bulletin. Feel proud to have your articles published in this Bulletin that is circulated throughout the industry and MPOB offices worldwide.

fossil fuel-fired package boilers with biomass boilers. This was indeed a wise move as they could effectively cut down their fuel cost since they are unaffected by fluctuations of crude oil price. When we say unaffected, it can work both ways like they also can raise the biomass price without any control. There will always be problems caused by unscrupulous millers who become greedy and raise the price of biomass to make it very unaffordable for buyers leading sometimes to the closure of the factory itself.

In order to establish some scientific foot-ing for putting a price tag on a good fuel like kernel shell, a simple method of float-ing its value against coal is suggested in this issue. Perhaps, the kernel buyers and millers can have a dialogue on the pricing mechanism, so that the kernel shell price does not spiral up indiscriminately leav-ing no margin for the renewable energy power plants to survive. Previously, there was no such need for this but now judg-ing by the strategy of the biomass boiler operators, this price tagging is expected to benefit them in a big way.

In order to add fairness to the fuel pur-chase, probably it is time for the stake-

holders to agree on a pricing scheme purely based on the calorific value of various biomasses. The price can be pegged to the global price of common fuels like coal and its calorific values. A pricing factor can be worked out for the various biomasses based on the calorific value, transport cost, geographic factors etc. agreed upon by millers.

This scheme will be extremely useful for fuel purchasers to work out the internal rate of returns for a new renewable energy power plant or other plants using biomass as fuel. The national authority for maintaining the biomass fuel price could be vested with Pusat Tenaga Malaysia, which can fix up monthly prices for various types of fuels available in the country based on a common solid fossil fuel. The price may consist of two parts, one based on say, the coal price and the other a deduction factor based on factors mentioned earlier. Some details are given in this issue to illustrate the method of computation. Some may, as usual, argue that no one in the world has set up any pricing on their biomass and as such why should we do it. The answer is why should we wait for others to start this if we can do it ourselves.


Recent Events Contributed by: Noor Asmawati Abd Samad*

* Malaysian Palm Oil Board, P. O. Box 10620, 50720 Kuala Lumpur, Malaysia.

MoU between MPOB and Donghwa

MPOB signed a memorandum of understanding (MoU) with Dongwha GH International Sdn Bhd on 3 April 2009 at MPOB Head Office for a collaborative commercial production of medium-density fibreboard (MDF) using oil palm biomass. Dongwha GH International Sdn Bhd is a

PAC MeetingThe 29th Programme Advisory Committee (PAC) meeting was held from 6 to 10 April 2009 at MPOB Head Office. The PAC is a committee established by the MPOB govern-ing Board to advise MPOB on the research programmes that it wished to undertake. This is to ensure that the research projects of MPOB are technically sound and in line with the needs of the industry and nation.

subsidiary of a South Korean wooden panel producer. Datuk Dr Mohd Basri Wahid, the Director-General, represented MPOB, while Mr Lee Byeong Eon, the Director, represented Dongwha.

The collaboration between MPOB and Dongwha in this particular field is expected to further enhance confidence and eventu-ally serve as an impetus for the industry in the utilization of oil palm biomass.


Recent Events

Most of the PAC members are multi-disciplined with diverse expertise, knowledge, experience and background to help the Board in this regard. Two new members were appointed during the recent PAC meeting. They are Dr Karlheinz Hill, Cofnis GmbH, Germany and Mr Trevor Tomkins, Milk Specialities Global, USA.

During the meeting, Dato’ Sabri Ahmad, the chairman of MPOB, also hosted a din-ner to welcome the PAC members. On the final day of the session, the PAC members visited the Farm Mechanization Centre and Biomass Technology Centre at MPOB/UKM Research Station, Bangi, Selangor.

PAC SeminarMore than 360 participants attended a half-day seminar at Dewan Bactris, MPOB Head Office on 9 April 2009. The seminar was held in conjunction with the 29th PAC meeting.

The seminar was conducted in five sessions, namely,

• Seminar 1: Is GM the Way Forward? by Prof Denis J Murphy, University of Galmorgan, United Kingdom;

• Seminar 2: Tocopherol – A Suicidal Vitamin E Supplement Tocotrienols – A Logical Fu-ture Research Target by Dr Gee Ping Tou, Palm Nutraceuticals Sdn Bhd, Malaysia;

• Seminar 3: Green Oleochemical Products: Recent Development and Consumer

Acceptance by Dr Karlheinz Hill, Cognis GmbH, Germany;

• Seminar 4: Utilization of Palm oil in Animal Feed – New Horizon by Trevor Tomkins, Milk Specialities Global, USA; and

• Seminar 5: The Challenges Facing Palm Oil in the 21st Century by Dr James Fry, LMC International, United Kingdom.

The seminar was held to disseminate information on the latest research and development in the oil palm industry.

Press Conference on Oil Palm Seed Scam Syndicate

During a media conference on 24 April 2009 at MPOB Head Office, Datuk Dr Mohd Basri Wahid, the Director-General of MPOB, exposed a syndicate which was involved in the unlawful sale of fraud oil palm seeds and the forging of transaction documents bearing logos of Sime Darby Plantation Bhd and FELDA Agriculture Services Sdn Bhd (FASSB).

The syndicate has been conducting fraudulent sale of low-yielding seeds to planters. This may have serious implications as they are bound to adversely affect the livelihoods of thousands of smallholders and the country’s average oil palm yield.

Since May 2008, MPOB has conducted 24 raids and seized 6.13 million fake DxP seeds. This amounts to RM 11.35 million


Recent Events

worth in opportunity loss for genuine cross-bred seed producers. So far, eight cases have been brought to court.

Under the MPOB licensing rules, those found guilty are fined up to RM 200 000 or jailed up to three years or both.

The media conference was attended by Mr S Palaniappan, Chief Executive of FASSB and Mr Khairudin Hashim, Head of Research and Development, Sime Darby Plantation.

Visit of new Minister of Plantation Industries and

Commodities to MPOBThe new Minister of Plantation Industries and Commodities, Tan Sri Bernard G. Dom-pok and the Deputy Minister, Dato’ Ham-zah Zainudin visited MPOB Head Office on 7 May 2009. Dato’ Sabri Ahmad, the Chair-

man of MPOB; Datuk Dr Mohd Basri Wahid, the Director-General and senior officials of MPOB greeted the delegation on their ar-rival. The Director-General gave a briefing on MPOB before the delegation proceeded to visit several research facilities in MPOB complex, namely, Margarine Pilot Plant, Demonstration Kitchen and Gallery.

Transfer of Technology Seminar

Tan Sri Bernard G. Dompok, the Minister of Plantation Industries and Commodities officially launched the Transfer of Technology (TOT) Seminar 2009 on 18 June 2009 at MPOB Head Office.

The TOT Seminar is organized by MPOB annually to ensure that the industry is aware of the latest research results available for adoption and commercialization. Adoption of new technologies will increase productivity, add value, generate wealth


Recent Events

and contribute to the well-being of the oil palm industry in the country.

By the year 2008, MPOB had launched a total of 412 technologies/products and 56 services, and in 2009, 39 new technologies and products and 16 services had been launched, increasing the total number of technologies to 451 and services to 72.

During the event, Tan Sri Bernard G. Dompok also launched one new product namely, NoveLin. The NoveLin was devel-oped with innovative features like cold sta-bility that makes it suitable for markets in temperate countries. The technology has been commercialized by Ace Edible Oil In-dustries Sdn Bhd.

Tan Sri Bernard G. Dompok also launched two publications entitled Technologies for Oil Palm Harvesting, Evacuation and Loose Fruit Collection, and Journal of Oil Palm Research: Special Edition during the event.

Coinciding with this event, Tan Sri Bernard G. Dompok also witnessed the signing of agreement between MPOB and three local companies to develop and commercialize palm-based products. The companies are I-NAI Venture Holdings Sdn Bhd, Emery Oleochemical (M) Sdn Bhd and Hur Far Engineering Sdn Bhd.

Tan Sri Bernard G. Dompok also officially launched the MPOB Palm Biodiesel

Integrated Pilot Plant in conjunction with the TOT Seminar 2009.

Dato’ Hamzah Zainudin, the Deputy Minister of Plantation Industries and Commodities; Ms Nurmala Abd Rahim, Deputy Secretary-General of the ministry; Dato’ Sabri Ahmad, Chairman of MPOB and Datuk Dr Mohd Basri Wahid, Director-General of MPOB, also attended the event.

GSAS SeminarA total of 150 participants attended the MPOB Graduate Students’ Assistantship Scheme (GSAS) Seminar at MPOB Head Office on 19 June 2009. Dr Salmiah Ahmad, the Deputy Director-General (Services), officially opened the Seminar on behalf of the Director-General, Datuk Dr Mohd Basri Wahid.

The objectives of the seminar was to give emphasis on human capital development in order to enhance the nation’s capability to compete globally, to strengthen national unity, and to bring about a better distribu-tion of income and wealth leading to a high quality of living for the people.

So far, MPOB has sponsored 115 students under the scheme and 59 of them who have graduated are currently serving and contributing to the nation in various sectors.


Forthcoming Events

2009 MPOB TRAINING PROGRAMME SCHEDULE

CODENO.

TITLE DATE VENUE

A COURSES

1 OIL PALM

A1.1 Kursus Kemahiran Menggred Buah Sawit

Bil. �: Wilayah Sabah ��-�0 April Hotel Emas,Tawau, Sabah

Bil. �: Wilayah Sarawak �0 Jun-� Julai Hotel Four Point,Kuching, Sarawak

Bil. �: Wilayah Tengah ��-�� Jun Hotel Le Paris, Port Dickson,

Negeri Sembilan

Peperiksaan Kemahiran Menggred Buah Sawit

Peperiksaan Bil. ��: Sabah �� Julai PLASMA,Lahad Datu,

Sabah

Peperiksaan Bil. ��: Semenanjung �� Ogos Wilayah Tengah

A1.2 11th Intensive Diploma in Oil Palm Management & Technology (IDOPMT)Semester IEstate AttachmentSemester IIEstate AttachmentSemester III

�� April-� May��-�� May

�� May-�� June�� June-� July

�-�0 July

MPOB HQ

A1.3 Kursus Operator Mekanisasi Ladang � Sept. �00�-� Feb. �0�0

PLASMA,MPOB UKM

PALM OIL ENGINEERING BULLETIN NO. 91�0

Forthcoming Events

CodeNo.

Title Date Venue

A1.4 Kursus Pengurusan dan Penyelenggaraan Tapak Semaian Sawit

Bil. �: Wilayah Sabah ��-�� April Hotel Sandakan,Sandakan,

Sabah

Bil. �: Wilayah Selatan �-�0 Jun Hotel Prime City, Kluang,

Johor

Bil. �: Wilayah Timur ��-�� Ogos Felda Residence, Sg. Tekam, Kuantan, Pahang

Bil. �: Wilayah Utara �-� Okt Hotel Legend Inn, Taiping,

Perak

2 PALM OIL

A2.1 Diploma in Palm Oil Milling Technology and Management (DIPOM)Semester IISemester IIIExam. Semester III

��-�0 May�� June - � July��-�� August

MPOB HQ

A2.2 The 23rd MPOB Oil Palm Products Surveying Course

The 22nd MPOB Oil Palm Products Surveying Examination

��-�� June

��-�� June

MPOB HQ

MPOB HQ

A2.3 Kursus Penyelia Kilang Minyak SawitPeperiksaan

�-� Ogos� Okt

MPOB HQ

A2.4 Kursus Pengendali Makmal Kilang Minyak SawitPeperiksaan

�0-�� Julai

�� Julai

MPOB HQ

A2.5 Colour Cosmetic Course �-� August

MPOB HQ/ AOTD

PALM OIL ENGINEERING BULLETIN NO. 91 ��

Notes: * To be confirmed. + By invitation. ** Course approved under PROLUS scheme of Pembangunan Sumber Manusia Berhad.

For enquiry or further information, please contact:

HRD & Conference Management UnitTel. No. : 0�-��00 ext. ��, ��0, ��Fax No. : 0�-��E-mail : [email protected]’s website : http://www.mpob.gov.my

1. MPOB Transfer of Technology (TOT) Seminar �00� �� June MPOB HQ

2. GSAS Seminars �� June MPOB HQ

3. International Conference on Palm Oil and the Environment

��-�� August MAEP,Serdang,Selangor

4. PIPOC �00� �-�� Nov. KLCC, Kuala Lumpur

5. SME TOT Seminar �00� �0 Dec. MPOB HQ

Forthcoming Events

2009 MPOB CONFERENCES/SEMINARS

CODENO.

TITLE DATE VENUE

B CONFERENCES/SEMINARS


Feature Article

Palm Waste as Alternative Fuel for Cement PlantAndrew Yap Kian Chung*

C

* Malaysian Palm Oil Board, P. O. Box 10620, 50720 Kuala Lumpur,

Malaysia.

ABSTRACT

the kiln in which toxic materials such as dioxin can be discomposed at a high tem-perature of about 1450˚C. Conventional ce-ment plants depend on coal to provide the heat energy needed. Since clinker is used as the raw material for the production of ce-ment, no secondary waste material will be generated. In order to mitigate environmen-tal issues like carbon emission reduction, palm biomass can be used to replace coal. This may qualify for carbon credit under the Clean Development Mechanism (CDM). However, recycling of waste as an alterna-tive fuel will increase the volume of vola-tile components, particularly chlorine (Cl), sulphur (S), and alkaline substances (Na, K) causing pre-heater deposits and cyclone clogging in the cement clinker burning sys-tem. This will lead to the development and installation of chlorine by-pass and anti-sul-phur coating system into the clinker pre-heater plant.

INTRODUCTION

This article examines the issues involved in the use of palm oil by-products as a sub-stitute fuel for the cement kilns, where the

ement industries usually with high production capacities utilize a lot of heat energy to produce cement in

kiln temperatures are kept at about 1450˚C. As palm oil millers may not have sufficient knowledge on cement production, an at-tempt is made in this article to introduce the technology involved to millers so that they can appreciate the various problems the ce-ment industry will face when the fuel is re-placed with palm biomass.

Portland cement is a type of hydraulic cement made by heating and pulverizing a mixture of limestone (CaCO3), clay (Al2SiO5), shale, laterite, iron ore (Fe), fly ash and gyp-sum (CaSO4•2H2O) which are widely used in the production of cement. The major ce-ment producers in Malaysia are Associated Pan Malaysia Sdn Bhd, Tasek Corporation Berhad and Cement Industries of Malaysia Berhad. Wet process kilns are less energy ef-ficient compared to the dry process kilns as shown in Table 1 (CIPEC, 2001).

There are three fundamental stages in the production of Portland cement as shown in the Figure 1.

Preparation of the Raw Mixture

Limestone, clay, shale and other raw ma-terials are ground and mixed in a raw mate-rial mill.

Production of the Clinker

The raw mixture is heated in a mult-stage pre-heater and then fed into a rotating kiln with temperatures gradually

PALM OIL ENGINEERING BULLETIN NO. 91��

Feature Article

increasing over the length of the cylinder up to a peak temperature of about 1450°C. A complex succession of chemical reactions take place as the temperature rises. The peak temperature is regulated so that the product contains sintered but not fused lumps. Sintering consists of the melting of 25% - 30% of the mass of the material. The resulting liquid draws the remaining solid particles together by surface tension and acts as a solvent for the final chemical reaction in which alite is formed. Too low a temperature causes insufficient sintering and incomplete reaction, but too high a temperature results in a molten mass or glass, destruction of the kiln lining, and waste of fuel. The clinker produced is fed into a clinker cooler before it is conveyed for storage. The clinker can be stored for a number of years before use.

TABLE 1. AVERAGE FUEL CONSUMPTION COMPARISION

Kiln type Average consumption (GJ t-1)

Wet kilns 6.0

Dry kilns single stage pre-heater 4.5

Dry kilns multi stage pre-heater 3.6

Figure 1. Portland cement production flow chart.

The enthalpy of formation of clinker from calcium carbonate and clay minerals is about 1700 kJ kg-1. However, because of heat loss during production, actual values can be much higher.

Preparation of the Cement

Although the chemistry of the raw mix may have been tightly controlled, the kiln process potentially introduces new sources of chemical variability. In order to achieve the desired setting qualities in the finished product, a quantity of gypsum is added to the clinker and the mixture is finely ground to form the finished cement powder. This is achieved in a cement mill. The grinding process is controlled to obtain a powder with a broad particle size range, in which


Feature Article

Stiffening, setting and hardening are caused by the micro-structure formation of hydration products with varying rigid-ity which fills the water-filled interstitial spaces between the solid particles of the ce-ment paste, mortar or concrete. The behav-iour with time of the stiffening, setting and hardening therefore depends to a very great extent on the size of the interstitial spaces which depend on the water-cement ratio. The grain size of the cement and admixtures which is micro silica or nano silica affects the particle distance and therefore the final compressive strength. Typical grain sizes for cement vary between 10 µm to 20 µm. A good mixing and dispersing of all cement and admixture particles are needed to obtain optimal concrete properties after hardening. The hydration products primarily affecting the strength are calcium silicate hydrates. Further hydration products are calcium hy-droxide, sulphatic hydrates (AFm and AFt phases), and related compounds, hydrogar-net and gehlenite hydrate. Calcium silicates or silicate constituents make up over 70% by mass of silicate-based cements. The hydra-tion of these compounds and the properties of the calcium silicate hydrates produced are therefore particularly important. Calci-um silicate hydrates contain less CaO than the calcium silicates in cement clinker, so calcium hydroxide is formed during the hy-dration of Portland cement. This is available for reaction with supplementary cementi-tious materials such as ground granulated blast furnace slag and pozzolans. The sim-plified reaction of alite with water may be expressed as:

2Ca3OSiO4 + 6H2O → 3CaO•2SiO2•3H2O + 3Ca(OH)2 (1)

This is a relatively fast reaction, causing set-ting and strength development in the first few weeks. The reaction of belite is:

2Ca2SiO4 + 4H2O → 3CaO•2SiO2•3H2O +Ca(OH)2 (2)

typically 15% by mass consists of particles below 5 µm diameter, and 5% of particles above 45 μm. The measure of fineness usu-ally used is the specific surface, which is the total particle surface area of a unit mass of cement. The rate of initial reaction (up to 24 hr) of the cement on addition of water is directly proportional to the specific surface. Typical values are 320 - 380 m2·kg-1 for gen-eral purpose cements, and 450 - 650 m2·kg-1 for rapid hardening cements. The cement is conveyed by belt or powder pump to a silo for storage. Cement plants normally have sufficient silo space for 1 - 20 weeks produc-tion, depending upon local demand cycles. The cement is delivered to end-users either in bags or as bulk powder blown from a pressure vehicle into the customer’s silo.

SETTING AND HARDENING

Setting and hardening of Portland cement is caused by the formation of water-con-taining compounds, forming as a result of reactions between cement components and water. Usually, cement reacts in a paste mix-ture only at water/cement ratios between 0.25 and 0.75. The reaction and the reaction products are referred to as hydration and hydrates or hydrate phases, respectively and a stiffening can be observed which is very small in the beginning, but increases with time widely depending upon the mix used and the conditions of curing. The point in time at which it reaches a certain level is called the start of setting. The subsequent consolidation is called setting, after which the phase of hardening begins. When water is mixed with Portland cement, the cement paste sets within a few hours and hardens over a period of weeks. A typical concrete sets in about 6 hr and develops a compres-sive strength of about 8 MPa within 24 hr. The strength rises to about 15 MPa after three days, 23 MPa after one week, 35 MPa after four weeks, and 41 MPa after three months. Concrete is usually allowed to dry out after a few weeks, and this causes strength growth to stop (Wikipedia, 2009a).


Feature Article

This reaction is relatively slow, and is main-ly responsible for strength growth after one week. Tricalcium aluminate hydration is controlled by the added calcium sulphate, which immediately goes into solution when water is added. Firstly, ettringite is rapidly formed, causing a slowing of the hydration:

Ca3(AlO3)2 + 3CaSO4 + 32H2O → Ca6(AlO3)2

(SO4)3•32H2O (3)

The ettringite subsequently reacts slowly with further tricalcium aluminate to form monosulphate - an AFm phase:

Ca6(AlO3)2(SO4)3•32H2O + Ca3(AlO3)2 + 4H2O → 3Ca4(AlO3)2(SO4)•12H2O (4)

This reaction is complete after one to two days. The calcium alumino-ferrite reacts slowly due to precipitation of hydrated iron oxide:

2Ca2AlFeO5 + CaSO4 + 16H2O → Ca4(AlO3)2(SO4)•12H2O + Ca(OH)2 + 2Fe(OH)3 (5)

The pH value of the pore solution reaches comparably high values and is of impor-tance for most of the hydration reactions.

Soon after Portland cement is mixed with water, a brief and intense hydration starts (pre-induction period). Calcium sulphate dissolve completely and alkali sulphates almost completely. Short, hexagonal needle-like ettringite crystals form at the surface of the clinker particles as a result of the reac-tions between calcium and sulphate ions with tricalcium aluminate. Further, origi-nating from tricalcium silicate, first calcium silicate hydrates, CSH in colloidal shape can be observed. Due to the formation of a thin layer of hydration products on the clinker surface, this first hydration period ceases and the induction period starts dur-ing which almost no reaction takes place. The first hydration products are too small to bridge the gap between the clinker parti-cles and do not form a consolidated micro- structure. Consequently, the mobility of the cement particles in relation to one another is

only slightly affected as the consistency of the cement paste turns only slightly thicker than normal. Setting starts after approxi-mately 1 to 3 hr, when first calcium silicate hydrates form on the surface of the clinker particles, which are very fine-grained in the beginning. After completion of the induc-tion period, a further intense hydration of clinker phases takes place. This third accel-erated period starts after approximately 4 hr lasting for 12 hr to 24 hr. During this period, a basic micro-structure forms, consisting of CSH needles and CSH leafs, platy calcium hydroxide and ettringite crystals growing in longitudinal shape. Due to growing crys-tals, the gap between the cement particles is increasingly bridged. During further hydra-tion, the hardening steadily increases, but with decreasing speed. The density of the micro-structure rises and the pores fill. The filling of pores causes strength gain.

Clean Development Mechanism (CDM) Project

Clinker production utilizes huge amount of heat energy estimated at 767 kcal kg-1 usu-ally generated from coal. In order to reduce the consumption of fossil fuel, palm biomass such as palm kernel shell could be used as a good alternative fuel (Mohammad, 2007). Table 2 shows the dry basis calorific value of different type of palm waste based on ASTM 2015 standard method (Vijaya et al., 2004).

Thus, the cement industry could reduce its dependence on fossil fuels by utilizing palm biomass as an alternative fuel thus qualifying as a Clean Development Mecha-nism (CDM) (CDM Energy Secretariat, 2006). Carbon dioxide equivalent is a quantity that describes the amount of CO2 that would have the same global warming potential for a given mixture of greenhouse gases (GHG) over a specified time-scale thus reflecting the time integrated radiative forcing. Equivalent carbon dioxide is the concentration of CO2 that would cause the same level of radiative forcing as a given type and concentration of greenhouse gases (Wikipedia, 2009b). Emis-sion factors from Waste Reduction Model


Feature Article

TABLE 2. DRY BASIS CALORIFIC VALUE OF PALM WASTE

Sample Average calorific value(kcal kg-1)

Range(kcal kg-1)

Empty fruit bunch, EFB 18 795 18 000 – 19 920

Fibre 19 055 18 800 – 19 580

Shell 20 093 19 500 – 20 750

Palm kernel cake 18 884 18 880 – 18 895

Nut 24 481 24 265 – 24 830

Crude palm oil 39 360 39 330 – 39 385

Kernel oil 38 025 37 947 – 38 086

EFB liquor 20 748 20 567 – 20 899

Palm oil mill effluent 16 992 16 100 – 17 650

Trunk 17 471 17 000 – 17 800

Frond 15 719 15 400 – 15 950

Root 15 548 15 300 – 15 680

(WARM) were used to develop the conver-sion factor for recycling rather than land-filling waste. These emission factors were developed following a life cycle assessment methodology using estimation techniques developed for national inventories of GHC emissions. According to WARM, the net emission reduction from recycling mixed re-cyclables (paper, metals, plastics etc.), com-pared to a baseline in which the materials are landfilled, is 0.79 MTCE per short tonne. This factor was then converted to a tonne of carbon dioxide equivalent (MTCO2E) by multiplying by 44/12, the molecular weight ratio of carbon dioxide to carbon as shown in the equation below (EPA, 2006).

0.79 MTCE/t x 44 g CO2/12 g C = 2.90 t CO2

E/t of recycled waste (6)

Recycling of waste as an alternative fuel has increased the volume of volatile com-ponents, particularly chlorine (Cl), sulphur (S) and alkaline (Na, K) which have caused problematic pre-heater coatings and cyclone clogging in the cement clinker burning sys-tem due to the formation of low melting

point compound. Chlorine coating is mainly generated at the area of the rising duct and the bottom cyclones whereas sulphur-based coating mainly appears at the kiln inlet, ris-ing duct due to the difference in condensa-tion rates and temperature reactiveness be-tween chlorine and sulphur. Thus, chlorine could be removed efficiently using by-pass system but not practical for sulphur due to generation of enormous by-pass dust. Anti-sulphur coating system has been developed instead (TEC, 2009).

Chlorine By-pass System

Kiln exhaust gas is extracted by probe and is cooled rapidly to a temperature of about 600˚C to 700˚C which is lower than the melting points of chlorine compounds. Coarse dust with relatively low chlorine concentration is separated by cyclone whereas fine dust, particle size below 10 µm, with high chlorine content is collected by bag filter. All dust particles returned to the kiln system are ground and mixed into cement during the grinding process (TEC, 2009).


Feature Article

Coating Solution System for Sulphate

Sulphate mist in the kiln exhaust gas con-dense to liquid at the surface of kiln feed end. It acts as an adhensive agent between pre-heater wall and kiln dust or among kiln dust themselves. Thus, a coating grows on the wall over an operating period. The developed coating solution system controls the cooling of the kiln exhaust gas so that minimum sulphate mist would condense at the surface of the pre-heater wall. As soon as the sulphate mist condenses, it contacts with kiln dust and form lump of kiln dust due to the adhesion property of the con-dense sulphate mist. Thus, coating forming on the pre-heater wall could be avoided or reduced to minimum (TEC, 2009). The phe-nomenon of the sulphur coating is shown in Figure 2.

CONCLUSION

Palm biomass waste could be used as an al-ternative fuel to reduce the dependency of

coal in the cement industry. However, due to chlorine and sulphate content in the al-ternative fuel, chlorine by-pass system and sulphate coating solution need to be incor-porated into the multi-stage pre-heater sys-tem to avoid the clogging problem. Since all chlorine dust and sulphate dust lump are recycled to the kiln system, no second-ary waste would be produced. Thus, a CDM project could be formulated and cost of ce-ment production would be reduced.

REFERENCES

CDM ENERGY SECRETARIAT (2006). Ma-laysia CDM Information Handbook. Pusat Tenaga Malaysia, Selangor.

CIPEC (2001). Energy Consumption Bench-mark Guide: Cement Clinker Production. En-ergy Innovators Initiative, Canada.

EPA (2006). Waste Reduction Model (WARM). Environmental Protection Agency, USA.

MOHAMMAD, D (2007). Palm kernel shell (PKS) is more than biomass for alternative fuel after 2005. Proc. of the PIPOC 2007 In-ternational Palm Oil Congress - Chemistry & Technology Conference. MPOB, Bangi.

TEC (2009). Alternative fuel combustion in the cement industry: Taiheiyo chlorine by-pass system and Taiheiyo coating solution system. Taiheiyo Engineering Corporation, Tokyo, Japan. http://www.taiheiyo-eng.co.jp/egl/2a.html.

VIJAYA, S; CHOW, M C and MA, A N (2004). Energy database of the oil palm. Palm Oil Engineering Bulletin Issue No. 70. MPOB, Bangi.

WIKIPEDIA (2009a). Portland cement. Wiki-media Foundation Inc. http://en.wikipedia.org/wiki/Portland-Ccement

WIKIPEDIA (2009b). Carbon dioxide equiv-alent. Wikimedia Foundation Inc. http://en.wikipedia.org/wiki/Carbon-dioxide-equivalentFigure 2. Sulphate coating phenomenon.

Condensed sulphate mist

With Coating Solution System

Without Coating Solution System

Condensed sulphate mist


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I

How to Fix a Price for Your BiomassN Ravi Menon*

INTRODUCTION

am sure that many millers have no clue about the pricing of biomass. Most likely the merchants calling at the mill


Malaysia.

for its collection will offer a price acceptable to the mill manager and the deal is closed. In the next trip, the price would have changed mostly towards the higher end. In another mill, the price may be totally different as the whole transaction is conducted in a haphaz-ard manner without a clear basis.

As there is a growing demand for oil palm biomass either for power generation or for other purposes, the industry should estab-lish a system of fixing the biomass price based on fuel price against which it can be pegged. Perhaps, we should look closely into how we can generate a simple formu-lae for assigning prices for the biomass. This will certainly help the biomass consumers or investors for calculating their payback period and internal rate of returns. This ar-ticle shall touch upon a practical method of computing palm oil biomass prices based on some related factors.

Let us examine the following cases (of-ficial energy statistics from the US Govern-

ment Energy Information Administration) as at 13 March 2009.

• Spot prices of coal dust River Basin 8800 Btu (19 360 kJ kg-1) at USD 8.75 t-1

(RM 32 t-1).• Spot prices of Illinois Basin 11 800

Btu/lb (25 960 kJ kg-1) at USD 42 t-1 (RM 15 t-1).

As Btu and kJ are almost equal, we may ex-change the units for convenience.

For analytical purposes, let us assign the category 8800 kJ coal with the price USD 13 t-1 to the empty fruit bunches and the fibre as they have low calorific values. The cat-egory 11 800 kJ coal with the price USD 55 t-1

can be equated to kernel shell as it has high-er calorific value than the coal powder. The palm trunks and wood waste also could be slotted in this category.

The spot prices of biomass can also be pegged against the coal prices to get the ba-sic price but in addition a deduction factor will have to be introduced as the biomass has to undergo some preparatory work be-fore it is suitable as a fuel for the boiler. Let us analyse empty fruit bunches and kernel shell to find a method to fix a value for them at any time so that millers have something to fall back to.


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RAW EMPTY FRUIT BUNCHES ANALYSIS

Data available: Calorific value of dry empty fruit bunches

(mean) : 18 795 kJ kg-1

Assume moisture content: 67%Dryness fraction: 33%Calorific value of the raw empty fruit

bunches: 18 795 x 33% = 6202 kJ kg-1

Price of River Basin coal dust: (19 360 kJ kg-1) USD 8.75 t-1 = RM 32 t-1

Price of raw empty fruit bunch (propor-tionate): 32.00 x (6202/19 360)

= RM 10Deduction factors:

Geographical factors: 20%Preparation of fuel: 20%Handling etc.: 10%Total: 50%, Balance: 50%Calculated price: RM 10 x 50% = RM 5.00 t-1

The above is ex-mill price but most mills are reportedly selling empty fruit bunches at a price of RM 3 t-1 and that too if there is a ready buyer.

PROCESSED EMPTY FRUIT BUNCHES - ANALYSIS

Against a back drop of RM 3 t-1 for the raw empty fruit bunches (current price), the processed material commands a price of more than RM 300 t-1.

The moisture content of the baled empty fruit bunches is about 15% or 85% dry as against 33% dryness for the raw empty fruit bunches. So the quantity required will be 85/33 = 2.6 times.

Therefore cost of 2.6 t of empty fruit bunches = RM 5 x 2.6 = RM 13 t-1.The processing involves shredding, press-ing (brings down dryness to say 40%) fol-

lowed by drying to reduce the moisture to about 15%.The profit excluding processing cost is RM

300 – RM 13 = RM 287Power requirement is about 100 kW for a 40

t hr-1 mill.

Let us assume that the cost of processing is the same as the cost of the raw material, i.e. RM 13 (for 2.6 t of EFB at a price of RM 5 t-1 of EFB). Based on this, the profit margin is significant at RM 274.40 t-1 of baled empty fruit bunch or RM 105.38 t-1 of raw empty fruit bunch.

The above analysis shows that unproc-essed empty fruit bunches have very little value but once it is processed, its value in-creases 21-fold. The millers should consider the potential profit in transforming empty fruit bunches to a product that has a ready market. A palm oil mill in Perak is reported to export the baled empty fruit bunches to China for a price of more than RM 300 t-1.

KERNEL SHELL - ANALYSIS

This is the most sought after fuel produced by the mill as its calorific value in its dry form is moderately high at a mean value of 20 000 kJ kg-1. With 10% moisture the calor-ic value would drop to 18 000 kJ kg-1. This used to be an alternative fuel for the cement kilns in Malaysia as a replacement for coal. But the cement mills are finding it increas-ingly difficult to get this due to competition from other consumers of biomass like glove and noodle factories who were previously using package boilers. As mentioned earlier, let us put the kernel shell on par with the coal from Illinois basis with the following calorific value and price.

Spot prices of Illinois Basin Btu/lb (25 960 kJ kg-1), 5.0 SO2: USD 42 t-1 = RM 155.40 t-1.


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The price of kernel shell can be fixed as: 155.40 ( 18 000/25 960) = RM 107.75 t-1.

1.5 t of kernel shell will have the same heat energy as 1.0 t of Illinois coal based on their respective calorific values.

If we use the price of Illinois coal as the basis to compute the price of kernel shell, then RM 103.60 t-1 appears to be reasonable in terms of the heat content of the kernel shell but being a new type of fuel perhaps we may accept a price of at least 80% of this at RM 83 t-1 for kernel shell so that the buy-ers can see an advantage in buying this as a replacement of coal.

So when we want to know the spot price of kernel shell at any time, all we have to do is get the price of Illinois coal from the web-site and divided by 1.9 to obtain the price.

This is one of the logical ways of getting a fair price for your kernel shell without being unfair to the purchasers. Promoting green energy should be done by giving a realistic value for the biomass based on its actual heating value and not by downgrad-ing them as a waste material commanding low price.


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Codes of Practice (CoP) - What it Means for Millers?

N Ravi Menon*

INTRODUCTION

his is good news for millers. The MPOB-created Codes of Practice (CoP) are now undergoing actual


Malaysia.

field trials. We are happy to note that some plantation companies have realized the val-ue of CoP and have volunteered to have the CoP done in their plantation, nursery, mills and kernel crushing plants. Generally, it takes about two days to carry out the CoP audit in a plantation but for others it takes only one day each by teams comprising about four people. The audit can be done fast if photocopies of all the relevant docu-ments are in place and readily available for inspection.

Millers probably will want to know what this is all about. We shall briefly explain is-sues involved so that when MPOB comes and knock at your door for CoP audit you will know exactly what MPOB will be ex-pecting from you.

To begin with, the audit is not a fault find-ing exercise or a consultancy service. It is just like your financial audit exercise carried out by your internal auditors or the external ones with which millers are familiar with. The CoP is a code comprising a number of good practices that a mill is expected to fol-low so that the palm oil industry is not ex-

ploiting either the human resources or the environment for the sole purpose of fatten-ing the bank balance of the investor.

Three fundamental pillars form the basis of the code. They are:

• food safety; • sustainability; and • quality.

Most millers probably know these only too well but might not have taken them se-riously before but the right time has come for millers to defend the industry by ensur-ing that they are a caring lot and Malaysian palm products are marketable. Let us now try to analyse issues involved together with the remedy in getting CoP certification for mills.

FOOD SAFETY

As the word implies, the product we market should not contain traces of elements that are detrimental to the consumer’s health wherever they live. The product should not have different standard to cater for differ-ent peoples or animals of the world based on how developed or rich the countries are. The standard should be based on the con-cept of safe human or animal consumption.

Contamination can come from many sources like heavy metal, toxic products or microbes and all attempts should be made to prevent the entry of such products into the


final product that is marketed. In the case of palm oil mills, the possibility of contamina-tion by any of the above mentioned prod-ucts could be minimal but a thorough ex-amination should be conducted by the mill management to ensure that the assumptions are correct. Some of the fresh fruit bunch (FFB) contaminants could have accidentally slipped into the FFB consignment from the trader’s hopper or other sources. The drop-pings from birds, rats, cats or dogs should be prevented by denying them access to fin-ished products.

SUSTAINABILITY

Sustainability can be interpreted in many ways based on the whims and fancies of the person interpreting it. If sustainability is-sue is taken literally every human activity in this world may have to come to a stand still as they would indirectly generate car-bon dioxide in one form or other leading to global climate change. If we give up modern way of living and decide to live in the jungle maintaining solely by eating vegetables and fruits, we can say that we had a sustainable existence. So in this regard, we have to look at the big culprits that could cause major ca-tastrophe to the conservation of the ecologi-cal balance of the land.

In palm oil mills, the use of diesel gen-erators are considered to be a culprit that drags down the credit points generated by the steam power plants. So try not to use or reduce as much as possible the electric-ity your diesel generators produces or the supply imported from the national grid. In order to gain extra bonus, you may even generate and export to the grid.

QUALITY

Oil in contact with metals will pick up some of the metal and that is not encouraged. If we track the oil flow path from sterilizer on-wards, the oil is in close contact with mild steel or in some special cases with stainless steel. The oil pick-up iron from a number of points: sterilizer, thresher feeder, thresher,

fruit conveyors, fruit elevators, digesters, press, oil gutter, de-sander, crude oil tank, crude oil pump, clarification tank, pure oil tank, vacuum drier, pure oil pump and even in the storage tank. The high temperatures prevailing in some places like the digester and clarification tank can also promote the iron pick-up.

It needs Herculean effort to prevent the iron pick-up. The use of stainless steel to replace mild steel could perhaps reduce the iron pick-up but does not stop it altogether as stainless steel itself is not very different from mild steel except that it contains, in ad-dition nickel or chromium in small propor-tions.

Ceramic coating offers the best alterna-tive as it is non-metal and it is inexpensive. But the industry does not seem to be too keen to adopt for reasons not too clear. It could be due to lack of knowledge or fear of high cost. Millers are urged to focus their at-tention in this direction and aim for as much replacement of mild steel as possible so that our palm oil is of good quality that is always marketable to any part of the world.

A BRIEF SUMMARY OF THE AUDIT

Malaysian millers are fortunate in having the complete CoP covering six major ar-eas of detailed audit. The selected areas are (1) oil palm nursery, (2) plantation and smallholders, (3) palm oil mill, (4) palm oil refinery, (5) palm kernel crushing plant, and (6) palm product storage and transporta-tion. About a dozen officers from MPOB has already undergone the training to con-duct the audit and they are currently un-dergoing field trials with the lead auditors recognized by SIRIM.

The audit comprises two parts: (a) ad-equacy audit during which some recom-mendations will be made based on observa-tion and that need to be put in place within the next three months and (b) detailed au-dit is usually carried out three months after the first audit but may be vary depending

Feature Article


on convenience. This whole exercise is not a fault finding exercise to incriminate the management but for arming them with a tool to ensure that our palm products re-mains a sought-after product in the world market. It is a system quite parallel to the RESPO but more specific and focused.

During the audit exercise, the most dif-ficult task for the management, if it can be so called, is the presentation of documenta-tion. If the auditors ask a mill manager for the documentation pertaining to the train-ing that was given to his press operators, the answer would be that he does not have such document. Try to answer the following:

• is there any documentation on how each and every machine in the mill is operated so that a new recruit will know exactly the correct procedure for the op-eration of the plant?

• is there documentation on what proce-dure to follow when an accident occurs to a worker?

• are all safety guide-lines clearly dis-played at prominent places?

• are there any refresher courses for the workers conducted on regular basis? If so are they documented?

• are all visitors registered before they en-ter your mill with details on the purpose of their visit?

• what steps have you taken to prevent the entry of animals and rodents inside the mill?

• are the washroom kept clean? Does any senior officer conduct inspection on a regular basis to ensure that they are in-deed kept clean?

• is there a policy in place for ensuring that the FFB purchased is from honest deal-ers who do not add contaminants into FFB for increasing its weight-like regu-lar checking of the merchant’s yard?

• are products leaving the mill weighed out and their particulars documented?

• are the documentations regularly in-spected and monitored by senior man-agement staff?

You will be surprised to note that in most cases the answer would be NO. This ques-tionnaire is by no means complete. Please try to get ’YES’ for all and when we visit your mill for CoP audit, you can have a big laugh!

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Feature Article

Vynke’s Renewable Energy Steam Power PlantsN Ravi Menon*

he progress of renewable energy (RE) power plants had been relative-ly slow in Malaysia compared to its

neighbours. But silently some RE plants have been taking shape behind the scene and perhaps it is useful to highlight them here for the general knowledge of the in-dustry.

In this regard, it would be interesting to note that Vyncke Energietechnik has been selected by Frost & Sullivan as winner of their Southeast Asia 2008 Excellence in Technology Award. The technology they excelled was the steam generator Vyncke contributed for Chubu’s two 10 MW renewable power plants they recently set up in Sandakan which are supplying power to the state electricity grid.

In Sandakan, Vyncke has built two biomass-fired steam generators using its patented combustion and heat recovery technology for two power plants each with a net generation capacity of about 10 MW.

The plants are reported to export 82 000 MWhr to Sabah Electricity Sdn Bhd (SESB) grid under the SREP programme. This is expected to be sufficient to meet the power needs of up to 12 000 household and will account for about 5% of SESB’s total generating capacity. The entire fuel for this will be empty fruit bunches.

Vyncke, in Malaysia, appears to be play-ing a global role as they are now expected to manage projects even in Argentina with parts procurement and project management carried out by Vyncke of Malaysia, China and Europe. The main pressure parts were fabricated by various fabricators in Asia with some high-tech parts and the combus-tion grate being fabricated Europe.

SPECIAL FEATURE - DYNAMIC WATER COOLED STEP GRATE

On technological side, Vyncke has something to their credit - its worldwide patented Dynamic Water-cooled Step Grate (or DWS as it is popularly known) claimed to be one of the best available combustion technologies that handle all types of fuel - course to fine and wet to dry.

This step grate can reduce the formation of clinkers from fuel with low ash melting points that gives it higher availability exceeding 8000 hr. The life expectancy of the grates are increased due to the minimal exposure of the grates to extreme heat fatigue or undue thermal expansion.

The combustion air is blown into the furnace in a controlled way and is entirely dedicated for combustion purposes only. It is not for cooling the step grates. The step grate cooling is done by water circulation in a closed circuit. In order to achieve optimal combustion and efficient emission, control * Malaysian Palm Oil Board,

P. O. Box 10620, 50720 Kuala Lumpur, Malaysia.


is exercised on the exact air that is being admitted to the furnace.

This method deviates from conventional systems where the cast iron grates are cooled by the combustion air which results in regulation conflicts throughout the varying capacity regimes. This is found to reduce the grate cooling efficiency culminating in poor combustion.

Fuel Data

Type of fuel : Empty fruit bunches

Dynamic Water Cooled Step Grate Data

Type of firing grate : Dynamic Water-cooled Step Grate - 2 lanes.

Grate cooling medium : Water

Firing capacity : 55 MW t hr-1

Boiler Type

Boiler type : Horizontal type (tail-end boiler)

Number of empty passes : 2

Number of evaporator bundles : 2

Number of super heater bundles : 2

Number of economizer bundles : 3

Type of circulation : Natural

Type of circulation in economizer : Assisted circulation

Boiler Performance

Capacity of the boiler at feed water temperature of 105oC : 55 300 kg hr-1

Operating pressure at super heater outlet : 42 bar (a)

Design pressure : 59 bar (a)

Super-heated steam temperature : 420oC

Boiler efficiency - design : 83%

The DWS is also versatile in its ability to be extremely fuel flexible. As a result of the individually controlled air intake and pusher speeds, the DWS is able to handle a wide range of fuel with varying calorific values and moisture content while at the same time ensuring complete combustion with excellent emission.

Some of the data related to the power plant in Sandakan are given below:

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The First Chubu Electric Power Project in Malaysia

Company : Seguntor Bio-energy Sdn Bhd (location two).

Capital Investor : Location: Sandakan, Sabah.• Chubu Electric Power Com, Inc. • Go Bio Sdn Bhd (local construction company investing in

company).• SMEC Energy Sdn Bhd (Malaysia) (power production and

Engineering firm).• Agritech Marketing Co. Ltd (AMC) (Japan) - development and

investor of biomass power production company.

Power Generation Facilities

: 10 MW per location.

Fuel : Empty fruit bunches (170 000 t yr-1).

Construction Location : Sandakan.

Buyer of Electrical Power : Sabah Electricity Sdn Bhd (nationally owned electrical power operator).

Scheduled Start of Construction

: August 2006 (location one), October 2006 (location two).

Scheduled Start of Operation

: March 2008 (location one), May 2008 (location two).

Emissions Guaranteed

Dust particles (M150) : < 400 mg N m-3

Dust particles (ESP) : < 100 mg N m-3

Carbon monoxide : < 250 mg N m-3

NOx : < 450 mg N m-3

Smoke capacity : Ringleman 0-1

Boiler power consumption (parasitical load)

: 520 - 620 kWe

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The soot removal in this boiler is not done by steam blowing but instead it is done mechanically called ‘rapping system’ by which every single row of convection tubes are cleaned using very little energy. This ensures that the tubes are not subjected to

Project Scheme

LOAN

Construction Contract

erosion as is the case when steam blasting soot blowers are used. In this system, every row of tubes are cleaned with maximum efficiency. The rapping system, also requires very little maintenance compared to conventional soot blowing system.

2 million

Operation &


O

Feature Article

Mongana Basics: Part 17 - Oxidation of Oil**N Ravi Menon*

lefinic chains in contact with air undergo a slow oxidation process (becoming rancid). The primary


Malaysia.

** Continued from p. 37 of Palm Oil Engineering Bulletin Issue No. 90.

SIMPLIFIED THEORY

degree of this deterioration is the formation of hydroperoxides which attach themselves to the carbon atom adjacent to the double bond:

The early part of the reaction (A – B) is autocatalytic and may be represented graphically in Figure 1.

Only the first part of the curve is

representative of the degree of oxidation of the material.

The determination of peroxide value has made it possible to study the stability of palm oil in relation to oxidation. However, the correlation between peroxide value and the degree of oxidation of the oil applies only in the early stage of oxidation because

H |R - CH = CH - CH2- R ➞ R - CH = CH - C - R | O - OH

peroxides are very unstable (decomposition accompanied by release of energy).

PEROXIDE VALUE OF FRESHLY PREPARED OIL

All results are expressed as milliequivalents per kilogramme of the material. A perox-ide value of 1 corresponds to 0.008 g of ox-ygen per kg.

The determination procedure gives an accuracy of 0.5 peroxide value. It should be noted that the Wheeler value is expressed as millimoles of peroxide per kilogramme (a wheeler value of 1 corresponds to 0.016 g of oxygen per kilogramme of material).

Several other methods of assessing the oxidation status of oil have been tried, among which only the thiobarbituric acid (TBA) method deserves further considera-tion. The procedure is however difficult to use and less straightforward than the iodo-metric method which is the popular method currently used by the industry.

The pattern of oxidation as assessed by the determination of peroxide value according to Wheeler is not identical to that obtained by the TBA method as shown by the oxidation curves of oil in the course of time as illustrated in Figure 2.

Oil in the fresh fruit has a peroxide value lower than 1. After extraction under


favourable conditions, the peroxide value is lower than 2. After storage in the country of production, handling and transport to Europe or America, the peroxide value ranges between 1 and 12. Of the samples drawn ex-ship’s tanks in the port of discharge, 81% had a peroxide value of 5 or lower. No specifications as regards peroxide value of palm oil have been published in the technical literature. However, Hadorn and Jungkuntz recommend the following general specifications for oil:

Figure 2. Oxidation at 105oC of oil as measured by the peroxide value and thiobarbituric acid (TBA) values (meq kg-1).

Peroxide value between 0 & 3 = the oil can be stored.

Peroxide value between 3 & 6 = the oil can be stored for a limited period.

Peroxide value between 7 & 10 = the oil must be refined without delay.

An exception is made for olive oil for which a peroxide value of 8 to 10 is considered normal.

Figure 1. The autocatalytic oxidation zone.

Destruction of peroxides

Autocatalytic oxidation zone

see page 37

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TABLE 1. PEROXIDE VALUE OF OIL STORED AT AMBIENT TEMPERATURE

Type of oilTime (days)

0 6 27 53 71

Crude oil obtained by centrifugal extraction 0.7 1.1 1.0 1.9 2.0

Crude oil extracted by pressing 1.3 6.7 13.1 12.9 17.1

Water washed crude oil 1.1 2.1 4.3 3.0 4.2

Oil extracted with trichloroethylene 1.3 2.4 3.5 3.8 3.3

Oil extracted with xylene 1.1 1.9 2.3 2.1 3.0

Note: Crude oil extracted by pressing contains a large amount of water, impurities and ferments during storage.

The increase in peroxide value of oil in bulk of large tonnage is perceptible only af-ter several weeks of storage. Small amounts of oil, for which the ratio of surface to vol-ume is of consequence, show a sharper in-crease in peroxide value. Table 1 shows the pattern of oxidation on samples of approxi-mately 100 g stored in 250 ml beakers at am-bient temperature. In order to shorten the time of recording, that is to accelerate the oxidation process, a storage temperature of 60°C is normally used. At that temperature, the oxidation process is about eight times faster.

FACTORS AFFECTING PEROXIDE VALUE

Laboratory Tests

The following factors were studied:• drying;• heating under inert atmosphere;• washing;• de-gumming;• carotene content; and• initial peroxide value.

The experimental procedure consists in the determination at periodical intervals of the peroxide value of oil stored at 60°C. In some series of experiments, the samples

were kept in darkness as carotene exerts a pro-oxidizing effect in the presence of light and an antioxidizing influence in darkness. Numerous treatments were applied. The conclusion was reached that they are very seldom beneficial to the storage of oil and that in certain instances, they are markedly deleterious. The washing with surfactant for instance (quaternary ammonium and various alkyl-aryl-sulphonates) is clearly unsuitable.

Only the storage in sealed tubes of oil with or without prior treatment leads to a remarkable stability as regards peroxide value. A marked bleaching (destruction of the carotene) is however apparent.

Table 2 gives a summary of the results obtained through the following treatments:

• control; • oil dried during 1 min at 110°C;• oil stirred with water in a turbo mixer

for 15 s at 50°C;• oil stirred as in treatment No. 3 but

solution of A.A.S. (alkyl-aryl-sulphate) in a turbo mixer; and

• oil treated as in treatment No. 5 but subsequently dried.

Washing with citric acid and sodium

ethylene-diamine-tetracetate does not lead to improve keep ability.

from page 32


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The drying of oil, its effect on peroxide value and on the ability to withstand storage have been studied with the Swift apparatus using samples containing 0.3% moisture. Air insufflations at 80oC, 100oC, 120oC and 140oC was used.

In all cases, air bubbling was continued until moisture content had been reduced to 0.05%. As shown in Table 3, the drying induces an increase in peroxide value but very small magnitude.

Although peroxide value remains fairly steady during drying, it was necessary, however to ascertain whether the drying did not make the oil susceptible to post oxi-dation during subsequent storage, that is if oxidation did not become prevalent for the treated samples. The storage of oil in thin layer in petri dishes showed no difference between the treated and untreated oil. On the contrary, the partial oxidation sustained by oil during drying appears to slow down further oxidation to the point that the un-treated oil eventually catches up with the oxidized oil (Table 4).

Similar experiments were carried out at various temperatures with identical results. It may be concluded therefrom that

the drying of oil by air bubbling, although detrimental a priori, does not impair the quality of oil in the course of storage. The point was important because a deterioration would have prevented the used of air drying and would have made it mandatory to use vacuum drying for instance.

Absorption of Air

Whilst very little oxygen is taken up at low temperature during contact between oil and air, a marked absorption of the latter takes place. The removal of air from oil at high temperature enables the absorbed con-stituents to be titrated. The rate of absorp-tion can be measured in the Warburg appa-ratus. In the course of an ageing test over 50 hr at 80°C, oil takes up a little more than 100% of its volume, therefore about 0.1% of its weight. Only a fraction of the oxygen of the absorbed air is combined in the form of peroxide. Table 5 give values of the follow-ing against time: peroxide value, volume of absorbed oxygen, the corresponding milli equivalent value of oxygen per kg of oil and the ratio of combined to absorbed oxygen (temperature 80°C).

De-gumming appears to intensify the increase of peroxide value during storage.

TABLE 2. PEROXIDE VALUE AND COLOUR OF TREATED OIL STORAGE AT 60°C

Day of storageTreatment

1 2 3 4 5 6

Initially 1.7 3.2 - 3.1 2.2 3.2

4 days (open container) 7.3 12.0 10.2 - 9.0 8.2

14 days (open container) 37.5 39.2 40.5 - 56.0 41.1

5 days in sealed container 1.1 1.1 1.4 0.7 1.0 1.2

Colour expressed as optical density

Initially 87 91 90 86 89 87

4 days 81 78 79 70 75 76

10 days 49 28 20 5 7 2.6


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TABLE 3. EVOLUTION OF PEROXIDE VALUE AS A RESULT OF DRYING WITH AIR

Time80oC 100oC 120oC 140oC

% moisture

Peroxide value

% moisture

Peroxide value

% moisture

Peroxide value

% moisture

Peroxide value

Initial 0.30 3.5 0.30 3.5 0.30 3.5 0.30 3.5

30 s - - - - - - 0.13 3.9

60 s - - - - 0.09 4.0 0.08 4.0

2 min - - - - 0.04 4.2 - -

3 min - - - - 0.03 4.0 - -

4 min - - - - 0.01 4.5 - -

5 min 0.19 3.5 0.04 4.5 - - - -

10 min 0.04 3.6 0.02 4.9 - - - -

15 min 0.07 4.0 0.02 5.0 - - - -

20 min 0.01 4.1 0.02 5.9 - - - -

TABLE 4. STORAGE OF DRY OIL AT 60°C

Time lapse Initial oilOil dried at

80oC 100oC 120oC 140oC

Moisture content 0.30 0.03 0.05 0.05 0.06

Initial peroxide value 3.5 4.1 5.0 4.4 4.4

After 3 days 5.5 6.0 6.5 6.1 6.3

After 8 days 7.7 8.0 9.2 9.1 8.3

After 17 days 13.0 12.8 13.0 12.8 14.0

On the other hand, oil containing added mucilages shows improved stability.

Heating in an inert atmosphere reduces the peroxide value of oil. From an initial level of 8.5, peroxide value decreases to 5.6 after 30 min of heating at 115°C and 1.3 if 130°C is used. A portion of carotene is destroyed by the treatment (10% to 12%).

The effect of iron, whether in the form of metal or of soap is hardly noticeable or non-existent.

The initial peroxide value governs the pattern of the oxidation curve. The fact has been observed on sample of oil of vary different peroxide values as has been recorded in technical publications. The results of a few observations made on samples of oil with low peroxide value are collected in Table 6.

Industrial Trials

The washing of oil with detergents has been used extensively. This technique had


TABLE 5. ABSORPTION OF OXYGEN DURING STORAGE

Time (hr) Initial peroxide

value

Peroxide value increase

Volume of oxygen absorbed per unit

volume oil

Milliequivalents of absorbed

oxygen

Ratio of fixed to absorbed

oxygen

0 6.7 0 0 0 -

6 10.9 3.2 0.81 57.2 16%

21 – 25 14.5 7.8 0.96 79.0 18%

47 – 49 24.7 18.0 1.07 88.8 20%

TABLE 6. EVOLUTION OF PEROXIDE VALUE AS A FUNCTION OF THE INITIAL PEROXIDE VALUE

Initial PV After 4 days

After 8 days

After 17 days

% FFA mg of carotene for 100 g of oil

0.3 0.9 1.5 5.8 1.1 34.6

0.5 0.9 2.3 5.0 2.6 40.1

3.6 9.1 12.7 13.4 5.1 65.5

4.2 11.6 14.0 10.4 1.3 37.6

4.8 10.9 14.8 16.1 1.3 39.4

5.1 13.2 19.2 21.5 1.0 61.8

Note: PV – peroxide value. FFA – free fatty acid.

been adopted as a result of the beneficial affect reported by users, particularly in the USA, Following a large number of ship-ments of Congo oil to Europe and the USA. has been possible to establish that the use of detergents made the oil sensitive to oxi-dation. No difference in peroxide value is detectable immediately after the treatment but after a few weeks, the oxidation of oil in-creases sharply that seems to tend towards limit of 12 to 15. The washing of oil with detergents has consequently been stopped in Africa but still prevails in the USA for oil used in metallurgy.

NATURE OF THE PEROXIDES OF PALM OIL

The study required complex techniques. It was not our intention to investigate the

composition of the peroxides formed in the course of storage. We proposed however, to find out whether the peroxides of palm oil were peroxides of the unsaturated fatty ac-ids or carotene. With this objective in view, the peroxides were isolated by chromatog-raphy. The technique was tested on ground-nut oil that applied to palm oil.

The use of a solution of oil in chloroform on a Brockmann alumina column and elution with chloroform lead to no retention of peroxide and hardly any of coloured substances. On the other hand, when a solution in petroleum ether is used, the peroxide value of the elute is nil and various coloured bands appear. Elution with chloroform, after drying under nitrogen, of these coloured bands leads to the observation that none of these bands has a

Feature Article


special status as regards peroxide retention. The distribution appears to be uniform.

The use of Filtrol instead of alumina leads to marked retention with petroleum ether solution and elution with chloroform. The retention is less intense for the chloroformic solution and elution by the same solvent.

In order to separate the carotenes from the peroxides, use has been therefore made of the petroleum ether solution, which re-moved the corotenoids leaving the perox-ides, the latter being recovered by succes-sive elutions with chloroform.

Table 7 gives the results of the technique applied to palm oil with a peroxide value of 24.7 and ground-nut oil with a peroxide value of 21.8.

In the case of palm oil, the carotenoid bands are practically eliminated by the petroleum ether. In the case of ground-nut oil, the yellow band is eluted in the three fraction. The carotenoid content of the various fractions was determined through measurement of the optical density.

Table 8 gives the results of this test and Figure 3 gives the spectrum of the first four fractions.

TABLE 7. PEROXIDE VALUE OF DIFFERENT FRACTIONS

Petroleum ether Chloroform

1 2 3 4 5 Total

Palm oil 0 20.2 0.7 3.2 0.7 25.5

Ground-nut oil 0 16.9 3.2 1.2 1.0 22.4

TABLE 8. PEROXIDE VALUE AND OPTICAL DENSITY OF VARIOUS FRACTIONS

Type of solvent Petroleum ether CHCl3

Fraction of solvent 1 2 3 4 5 6 7

Peroxide value 0 5.7 5.1 2.3 2.3 5.2 0.6

Optical density at 420 µm 16.5 10.2 01.5 0.4 1.7 5.2 0.6

Feature Article


It may be concluded that although the elution of peroxides overlaps that of the var-ious coloured bands of the oil, it is however, possible to modify these overlaps by suit-able selection of the eluting solvents. There existing, therefore, a strong probability that peroxide which do not give the typical spec-trophotometric curve are not proxides of carotenoids.

The similarity between the results ob-tained for palm oil and ground-nut oil re-spectively makes it possible to be identical in both cases. This leads to the conclusion that the peroxides of palm oil are indeed derived from fatty acids and not from caro-tene.

Figure 3. Absorption spectrum of fraction of palm oil of 24.7 peroxide value obtained by chromatography on Brockmann alumina using petroleum ether as eluting medium.

Feature Article

wave length nm

nm


Milling Dialogue

Question 1: I am experiencing low KER of 4.95% against a potential of 5.12% in my mill caused by high losses. I have installed a strainer with a gap of 10 mm before the nut grading drum for the collection of whole kernel and broken kernel to avoid further crushing of the kernel in the ripple mill. The cracked mixture sample analysis indicated its composition as follows: whole kernel 51%, broken nuts 30%, kernel fragments 17% and fine stones. The amount of cracked mixture collected at that time appeared to be high. The nut grading screens used had three screen sizes of 12 mm, 15 mm and 17 mm and nuts were fed into three ripple mills having 36 rods. How do I improve my KER?

Answer: Many processing steps upstream need to be considered when problems like these are encountered in the production kernel. Nut conditioning starts at the sterilizer itself followed by heating within the digester and nut silo with heaters. It is possible that you may have high broken nuts in press fibre.

Diploma Course in Palm Oil Milling and ManagementTrouble Shooting Session on 20 May 2009

Panellist E-mailLee Kim Tiak, Mill Adviser, Sime Darby Plantation [email protected] Mei Kong, Manager, Airvenco Sdn Bhd [email protected] Ravi Menon, Senior Research Fellow, MPOB [email protected] Ramli, Head of Training, FELDA Plantation Group [email protected] Muhd Zain, Visiting Engineer, Boustead Est. Agency [email protected] Chai Seng, Mill Adviser, Sime Darby Plantation [email protected]

The following recommendations are given by the panel.

• Good digester drainage plays an important role in reducing the broken nut in an indirect way as by ensuring that the press cone pressure can be reduced significantly resulting in least broken nuts.

• The digester bottom plate must be able to extract 70% of the oil and only 30% extraction should be handled by the press.

• The press cone pressure could be set as low as possible if digester drainage is good.

• The digester temperature should not be allowed to drop below 90oC.

• Nut silo heaters are very useful as in it, the heat penetrates deep into the kernel and it gets dried to a large extent.


Milling Dialogue

• The bottom section of nut silo heaters are not provided with heaters but cold air will be blown through the ducting instead to allow the shell to cool so that the shell will not be remain elastic as otherwise in the nut cracker, nut will only be crushed but not cracked.

• Ripple mills are manufactured by many workshops that are not well versed with the basic principles and as a result some of them are badly designed. According to some experts, ripple mills must have 42 rods to be effective as a cracker. The best nut cracker is still the old centrifugal cracker, which is a magnificent machine for nut cracking.

The above are some of the recommendations. If after adopting the above views you still have problems, do not hesitate to write to us.

Question 2: I am facing a problem in nut cracking as my nuts are of varying sizes. My nut histogram shows 90% of my nuts at 10 mm diameter and 10% at 14 mm diameter. Can you suggest a solution for this problem?

Answer: The number of rods in your cracker rotor (32 as admitted by you) is inadequate to provide the right gap for good nut cracking. If you increase to 42, your problem would be solved.

Question 3: I have by-passed my pure oil vacuum drier buffer tank piping system and this is now causing a flooding of the vacuum drier. Is there a remedy for this?

Answer: Yes. Install back the buffer tank and also use a gear pump (level control auto cut off/on) to supply oil to the buffer tank. The efficient vacuum drier operation requires consistent oil feeding in order to obtain thin layer of oil flow on the buffer plates or from sprayer nozzles in the vacuum drier. In this case, flooding in vacuum drier could be due to fluctuation of oil level in pure oil tank. The oil flow and pressure head in the by-pass line is subject to oil level in the pure oil tank.

Question 4: I have excessive oil loss in my sterilizer condensate despite the fact that the FFB

and old bunches are segregated and sterilization is carried out under different automatic cooking regimes. The sterilizer pressure is maintained at 3 barg with continuous condensate bleeding to aid de-aeration. The mill uses 10 t cages, some of which have holes on side walls while others have no holes.

Answer: It was found that for large sterilizer cages or cages above 1.5 t, sterilization is poor if you do not have side holes for steam to enter in every part of the cage. When the cages become large the steam looses its latent heat on the top portion of the bunch and very little heat is available to bunches lying below with the result that the un-stripped bunches become abnormally high as found out during trail runs by Sime Darby. After making side holes, the heat penetration became more efficient and the un-stripped narrowed down to acceptable levels. Perforated heating pipes running along the cages also were found to significantly improve bunch strip ability according to Sime Darby trails.

In your case, bunches cooked in cages with holes performed differently from those without and that could be the reason for high losses.

Question 5: I am using poly pipe for my effluent distribution in the field. But crystals are seen to form within the pipe that causes pipe replacement. How do I avoid it?

Answer: One method is to flush out the effluent with fresh effluent or raw water after the days discharge. As the pipe can easily last about five years, it can not be considered a heavy expense for renewal of the pipe.

Question 6: How do we handle arrogant subordinates?

Answer: This is a human relations issue and it involves the right attitude and adaptability of individuals to accommodate each other. Dif-ferent approaches can produce different re-sponses and over a period of time every one will be able to arrive at an amicable method satisfactory to both parties.


Datasheet

CDM Status in Malaysia

Number of applications successfully registered with 34CDM Executive Board as at first quarter of 2009

Projects issued with carbon emission reduction certificates (CER) 5 valued at USD 5 t-1

amounting to 648 718 t CO2-eq = RM 12.3 million

Project Phase Issuance date Emissions reductions CO2-e equivalent

LDEO biomass steam and power plant in Malaysia.

1 2 3 4

2 Aug 0726 Oct 079 Apr 089 Oct 08

17 00614 75931 04934 245

SEO biomass steam and power plant in Malaysia.

1 2 3 4

8 Aug 0726 Oct 0718 Feb 086 Oct 08

24 07920 93241 09143 977

Sahabat empty fruit bunch biomass energy project.

1 17 Mar 08 12 775

Replacement of fossil fuel by palm kernel shell for the production of Portland Cement.

1 22 Dec 06 366 260

Biomass energy project, Lumut. 1 5 Oct 06 20 700

Source: Pusat Tenaga Malaysia.


ADVERTISEMENTue to the increased cost of printing, the advertisement rate for 2008 is RM 700 per issue for an A4 size page of black and white, whereas the cost for colour is RM 900. One year of complimentary Vendor’s List advertisement for every one page A4-size colour or black & white advertisement. Advertisers are required to submit to us either their own black and white artwork or colour separation films. Cheque should be made payable to the ‘Malaysian Palm Oil Board’. If you have any queries, please contact the following at MPOB.

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PALM OIL ENGINEERING BULLETIN ADVERTISEMENT – FULL PAGE ADVT.

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# * Made payable to ‘MALAYSIAN PALM OIL BOARD’.


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IST

ollowing a decision by the Editorial Board to further increase the role of Palm Oil Engineering Bulletin to serve the industry better, a new addition called Palm Oil Mill Vendor’s List has been introduced similar to Telekom Yellow Pages to assist mill engineers to know where to source materials or services pertaining to the industry. In order to make this useful, we need the co-operation of the mill engineers/managers to persuade their vendors to advertise in the Vendor’s List for a nominal fee of RM �00/year (four issues). If you have any queries, please contact the following at MPOB.

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Ir. Ravi Menon ext. �� or e-mail: [email protected] Ms. Lim Soo Chin ext. �� or e-mail: [email protected]

REPLY SLIP

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LEMBAGA MINYAK SAWIT MALAYSIA …palmoilis.mpob.gov.my/publications/POEB/poeb91.pdfPALM OIL ENGINEERING BULLETIN NO. 91 ISSUE NO. 91 (April - June 2009) LEMBAGA MINYAK SAWIT MALAYSIA