Bioenergy technology review for small-scale forest operators

Bioenergy technology review for small-scale

forest operators

Evaluating the potential products and applications from small-scale bioenergy technologies in the West

Kootenay area

Dave Lovekin

April 2015

The Pembina Institute ii Bioenergy Technology Review

Bioenergy technology review for small-scale

forest operators

Contents

Executive summary ................................................................................................................. 1

1. Introduction ..................................................................................................................... 5

1.1 Background .................................................................................................................. 5

1.2 Project objectives ......................................................................................................... 5

1.3 Project scope ............................................................................................................... 7

1.4 Technology readiness .................................................................................................. 9

1.5 Technologies out of scope ..........................................................................................11

1.6 Recent research and available resources....................................................................12

2. Background information ...............................................................................................14

2.1 Biomass energy ..........................................................................................................14

2.2 Bioenergy in B.C. ........................................................................................................14

2.3 Bioenergy in the West Kootenays ...............................................................................16

2.4 Small-scale forest operations in the Kootenays ...........................................................17

2.5 Wood wastes ..............................................................................................................17

2.6 Financials ....................................................................................................................21

2.7 Biotechnologies categories — further details ...............................................................21

3. Pre-processing and densification technologies ..........................................................25

3.1 Pre-processing — debarking .......................................................................................25

3.2 Pre-processing – chipping ...........................................................................................29

3.3 Densification – wood pellets ........................................................................................36

3.4 Densification – briquettes ............................................................................................41

4. Thermal and thermal-chemical conversion .................................................................46

4.1 Direct thermal combustion – heat ................................................................................47

4.2 Direct thermal combustion for power generation – Organic Rankin Cycle ...................55

The Pembina Institute iii Bioenergy Technology Review

4.3 Gasification for power generation ................................................................................59

4.4 Pyrolysis .....................................................................................................................63

5. Bioenergy technology examples – small-scale forestry .............................................67

5.1 Revelstoke Community Energy Corp. ..........................................................................67

5.2 Chisholm Lumber ........................................................................................................67

5.3 Madsen’s Custom Cabinets ........................................................................................68

5.4 Buchkirchen co-operative wood chip district heating system .......................................69

5.5 Lathrop Forest Products ..............................................................................................69

5.6 Hallander’s Sawmill and village district heating ...........................................................70

6. Case Study – Harrop-Procter Community Forest ........................................................71

6.1 Timber production and waste wood .............................................................................71

6.2 Potential products and application opportunities .........................................................73

7. Summary and Recommendations ................................................................................79

7.1 Commercial state of small-scale biotechnologies ........................................................79

7.2 Feedstock requirements ..............................................................................................81

7.3 Technical resources ....................................................................................................82

7.4 Recommendations – next steps ..................................................................................82

7.5 Debrief meeting with Harrop Proctor Forest Products .................................................83

The Pembina Institute iv Bioenergy Technology Review

Revision B – April 30, 2015

Disclaimer

This document is an independent report prepared exclusively as informational for the purposes of advancing bioenergy technologies in the West Kootenays. This project was funded by the Regional District of Central Kootenays Area E and the Columbia Basin Trust.

The views and opinions expressed in this report are those of the author.

The information, statements, statistics and commentary (together the ‘information’) contained in this report have been prepared by the Pembina Institute from publicly available material. The Pembina Institute does not express an opinion as to the accuracy or completeness of the information provided, the assumptions made by the parties that provided the information or any conclusions reached by those parties.

The Pembina Institute have based this report on information received or obtained, on the basis that such information is accurate and, where it is represented to The Pembina Institute as such, complete.

About the Pembina Institute

Leading Canada’s transition to a clean energy future.

The Pembina Institute is a national non-profit think tank that advances clean energy solutions through research, education, consulting and

advocacy. It promotes environmental, social and economic sustainability in the public interest by developing practical solutions for communities, individuals, governments and businesses. The Pembina Institute provides policy research leadership and education on climate change, energy issues, green economics, energy efficiency and conservation, renewable energy, and environmental governance. For more information about the Pembina Institute, visit www.pembina.org or contact [email protected].

The Pembina Institute 219 – 19 St NW Calgary, AB T2N 2H9 The author would like to thank the following individuals and organizations that provided information for this report.

• David Dubois – Wood Waste to Rural Heat Project

• Cornelius Suchy – Canadian Biomass Energy Research

• Martin Tempier – Envint Consulting

• Dominik Roser – FPInnovations

The Pembina Institute 1 Bioenergy Technology Review

Executive summary

The West Kootenay region, like many areas in B.C., is home to several dozen local sawmills, community forests and specialty wood manufacturing shops. The operators produce waste wood as a byproduct of their main operations, often in the form of sawdust, shavings, slabs and general hog fuel. Under current management practice, they give this waste resource away for free, openly burn it, or have it transported away to larger facilities at a cost to their operation.

Environmental, economic and social benefits can be achieved from finding alternate uses for their waste wood streams. Adopting mature commercial bioenergy technologies offers opportunities for reductions in greenhouse gas and other air emissions (by switching from fossil fuel systems to systems that use waste wood); increased business diversification / resiliency and local economic development; and deploying and showcasing technologies and technology innovation in this region.

Bioenergy technologies range from simple pre-processing of waste woods to higher value products through to more complicated thermal-chemical conversion technologies that transform the energy content embodied in waste wood to heat / electricity or higher value products including bio-oils, biochar and renewable transportation fuels. This research looks at a subset of near-commercial and fully commercial bioenergy technologies and plausible bioproducts and applications that can be produced from such technologies. After an initial scan that weeded out technologies that were still in the pre-commercial or research and development phase, research concentrated on the following technologies:

• pre-processing technologies including debarking and chipping

• densification technologies including wood pellets and wood briquettes

• direct thermal combustion technologies including the production of heat and power

• thermal chemical conversion technologies including gasification and pyrolysis

The appropriate bioenergy technology depends highly on the waste wood type (hog fuel versus sawdust), volume of waste wood, quality and characteristics of the waste, and capacity ranges of available technologies.

Based on previous research in 2010–2011, the annual volumes of waste wood produced by local sawmills and speciality wood shops vary from under 100 bone-dried-tonnes (BDT) per year on the low end to well over 10,000 BDT per year for medium-scale operations. The majority of these operators produce less than 4,000 BDT per year, with many in this category producing around 500 BDT. This research targets bioenergy technologies that have capacities that fit this annual waste wood profile.

The economic potential is significant; even at a modest value of $50/BDT, small-scale forest operators in the region collectively are giving away or burning over $2 million of an underutilized resource. The potential economic value of applying bioenergy technologies to upgrade their waste resource for direct applications or higher value products is substantial.

Scanning recent literature on small-scale bioenergy technologies, it is apparent there are ample mature, robust and commercial technologies for most of the selected technology categories. However it was surprising to learn that some technologies, specifically thermal-chemical


conversion technologies, are still traversing the gap from pre-commercialization to commercial operation. Table 1 summarizes the state of technology and applicability to small-scale forest operations in the region.

There is no shortage of technology opportunities available for small-scale forest operators. Many commercially proven technologies exist for direct heat or power applications (although gasification-to-power technologies are still questionable and regulations for connecting bioenergy power projects to the grid are currently limited), or technologies to produce higher value products including wood chips, pellets or briquettes. Bio-oil or biochar products derived from small-scale pyrolysis technologies appear to not be commercially viable at this point in time.

The main challenges with deploying biotechnologies include space requirements (finding the adequate space for both the technology and potential pre- and post-storage of feedstock); properly sizing the system based on current and future waste wood volumes (and balancing current needs with potential future needs); ensuring electrical requirements can be met (and choosing between electrical and diesel systems); and operational staffing and maintenance requirements. For technologies that produce wood chips, pellets or briquettes, it is very important that the fuel meets the specification of the end-use system so overall efficiency and performance of the system is maintained.

The technical challenges aren’t insurmountable; however, the real challenge to biotechnology deployment for small-scale operators is developing the financial business case and project economics. Even with the economic value intrinsic in the waste resource, biotechnologies and associated infrastructure require capital — and available capital is often very limited for these small enterprises. The environmental, economic and social benefits are apparent, but finding the appropriate business or financial model can be the biggest challenge.

The main recommendations from this report are:

• to continue disseminating and distributing this information to companies that are interested in learning more and are keen to find solutions

• to work with ally organizations in the West Kootenays that see all the benefits that can be achieved, in order to find ways to remove the financial barriers for these small enterprises

• to conduct a deeper economic and market analysis of the potential bioenergy products

Supporting these small-scale forest operators with expanding and diversifying their businesses to leverage what is now a lost economic opportunity in a cumbersome waste stream to much higher value products and direct applications is a worthwhile — and achievable — goal.


Table 1. Commercial state of small-scale biotechnologies – summary

Legend

Commercially-sound technologies; products are available in the marketplace

Commercially-sound technology but product availability in Canada is limited

Technology may not be commercial; positive economics questionable

Inadequate robust commercially-available technology available; projects are limited and/or require significant government funding

Technology Technology status

Availability of small-scale technologies*

Pre-processing – debarking

��

Pre-processing – chipping

��

Densification – pellets

��

Densification – briquetting

��

Direct thermal combustion for heat

��

Direct thermal combustion for power (ORC)

��

Gasification for power

��

Pyrolysis

�

*Note: � few small-scale technologies available

�� large number of small-scale technologies available


Definitions

Term Description

Biomass Any living organic material. In the context of bioenergy, typically trees, plants, agricultural crops and residues, animal waste products, municipal solid waste.

Biomass residue In the context of this work, biomass residue is waste streams from small-scale forest operators – i.e. sawdust, shavings, off-cuts, cants and bark.

For this report, the common term used for biomass residues is waste wood, and simply waste.

Feedstock Waste wood that is fed into the bioenergy technology. Typically the feedstock has gone through some sort of pre-processing and/or storage and has tighter definition and characteristics than the waste wood stream.

Green biomass Biomass containing at least 20% moisture.

Dry biomass Biomass containing less than 5% moisture.

One bone-dried-tonne (BDT)

The weight of a tonne of biomass that has very little moisture content. BDT is used in order to compare energy content of various biomass resources.

Bioenergy Energy derived from biomass sources. This can be in the form of heat, power or locomotion.

Solid biofuels Biofuels such as wood pellets and briquettes

Liquid biofuels Biofuels such as bio-oils, ethanol

Gaseous biofuels Biofuels such as methane and synthetic gas

Biogas Typically refers to gas produced from anaerobic digestion. Not to be confused with syngas.

Syngas A mix of gases created through the gasification of a solid or liquid fuel. It is composed of carbon monoxide (CO), hydrogen (H2) and smaller amounts of methane (CH4) and carbon dioxide (CO2). Depending on the gasification temperature and feedstock, the gas will also contain ash, water vapour, longer-chain carbon molecules, nitrogen, and other gases. Syngas made from biomass is either combusted in an internal combustion engine or fuel cell, or reformed and purified to create liquid biofuel.

Biochar Solid biofuel produced from slow pyrolysis for the purpose of soil fertility. Not to be confused with charcoal or biocoal.


1. Introduction

1.1 Background

The impetus for this research project stems from a half-day bioenergy meeting held in Nelson, B.C. in February 2012 where several key parties from municipal governments, independent consultants, non-profit environmental groups and the City of Nelson came together to discuss opportunities around further advancing bioenergy opportunities in the West Kootenay region. The meeting covered and reviewed three bioenergy feasibility studies conducted in 2011:

• City of Nelson Bioenergy Feasibility Study — summarizes the quantity and reliability of biomass residues available in the region that could be used as a feedstock for the proposed City of Nelson district heating system.

• Area E Bioenergy Feasibility Study — summarizes the quantity of wood fuels in Area E of the Regional District of Central Kootenays (RDCK) and local opportunities for utilizing wood fuels in buildings.

• Area D Bioenergy Feasibility Study — summarizes the quantities of wood fuels in Area D of the RDCK and local opportunities for utilizing wood fuels in buildings.

These three studies focused on the availability of waste wood (specifically forest-based waste wood from small and medium-sized mill operations and specialty wood manufacturing shops, logging residues from forest harvesting operations, and urban municipal waste) and local bioenergy heat opportunities for buildings that could benefit from this renewable resource.

The workshop concluded with the message and agreement that there are tremendous opportunities to capitalize on the economic value, environmental benefits and community advantages of using underutilized biomass residues in these regions. Some cases exist where small-small forest operations produce excess waste at their facility that is a logistical, managerial, economic and environmental burden to them. What is needed to further advance local bioenergy opportunities are champions, appropriate supply-demand connections, further understanding of appropriate and matching technologies deployment and viable financial and business models.

1.2 Project objectives

This research project focuses on available bioenergy technologies and takes a closer look at the potential applicable technologies and productions that exist for local forestry operations. Small-scale commercially-available bioenergy technologies are plentiful and there are also technologies at early commercialization which will soon reach technical maturity. Biomass resources have received increased attention in recent years because of their renewable nature; with this increase in attention, bioenergy technologies producing a variety of products and filling certain applications have increased.


The main goal for this research is to provide up-to-date technical information on the types of commercial and near-commercial bioenergy technologies along with the types of products and applications these technologies offer. Turning underutilized waste wood that is typically burned, discarded or transported out of the community into a product or application that could be used on-site or sold as a commodity provides economic, social and environmental benefits to business and the community at large.

This research does not discuss in any great detail the economic or financial requirements needed for successful implementation of specific bioenergy technologies. The financial business case or success of a project is governed by many factors; for example, capital costs of technology and additional infrastructure, operational and maintenance requirements (labour and equipment), economic value of the product produced, transportation costs of feedstocks or products, conventional system and fossil fuel replaced, increased operational efficiency of forestry operations as well as government programs / incentives / loans that might be applicable for the project under consideration. This research only provides some very high-level economic values for waste wood to provide insight into potential revenue streams.

This information is presented in a format that is hopefully helpful to small-scale forest operations that want to perform a preliminary evaluation of their waste wood asset and select from the most suitable bioenergy technologies.

Other goals of this research are:

Environmental

• Greenhouse gas reductions — the carbon dioxide reduction (CO2) benefits from displacing fossil fuels with biofuels (gaseous, liquid of solid) derived from waste biomass resources.

• Reduced air emission and improved local air quality — transitioning from uncontrolled burning of waste biomass to the controlled conversion of biomass to a usable product has the potential to improve air emissions and local air quality (air emissions are dependent on the quality and type of technology and emission reduction technology used).

• Reduced transportation — there are environmental benefits from reduced gasoline and diesel consumption when bioenergy products or applications can be used locally instead of transporting waste wood out of the community.

Economic

• Business resiliency / diversification — provide economic opportunities for local small-scale forest operations and non-profit forest communities to benefit from their current waste wood. Benefits include:

� improved waste management and operational efficiency

� capturing the economic value in waste wood as an energy source, instead of burning or disposing of it

� highlight new areas and markets that these businesses can potentially access to increase business resilience and profitability from utilizing their waste wood.


• Operational impacts — plan for and reduce the operational impacts of adding on-site management and usage of waste material or production of products.

• Local economic development — spin-off in community including local job opportunities.

Social

• Education — increase knowledge and awareness of the bioenergy sector and the state of commercialized and nearly commercialized technologies.

• Showcase technologies and technology innovation — leverage and promote the advancements of newer biotechnologies for small-scale operations and showcase these technologies in the West Kootenay region.

• Biomass as a visible wedge of local energy security — demonstrate that local waste biomass has the potential to increase energy security in the region, whether it is turned into heat, electricity or wood pellets,

• Extension to other sectors — extend the knowledge and information from this work to other forestry sectors including logging (where under forest management rules, logging residues are piled and burned), wildfire suppression / risk management and urban interface management.

1.3 Project scope

This project researches wood-based bioenergy technologies and potential products and applications derived from these technologies. The research is technology focused, relying on some key information published in recent years.

This project is scoped to reviewing bioenergy technologies that are applicable to small-scale forest operations in the West Kootenay region and the type of waste biomass they produce. Small-scale forest operations in the context of this work are defined as:

• local sawmills manufacturing traditional forest products (timber, dimensional lumber)

• wood manufacturing facilities that produce specialty products (timber framing, trusses, engineered timber, wood board producers, etc.)

• small-scale logging operations and local community forests that harvest trees and sell to local sawmills, wood manufacturing facilities or to businesses outside the area

The type of waste wood these facilities produce include hog fuel, sawdust, shavings, bark and slabs/off-cuts, which are all discussed in more detail in Section 2.5.3. Generally, these facilities produce waste wood volumes ranging anywhere from a few hundred tonnes to a few thousand tonnes annually. Although the focus is on the above small-scale forest operations, this information can extend to medium-sized and larger forest operations in the region.

1.3.1 Bioenergy technologies

The four main different bioenergy technology classifications included in this study are:

1. Pre-processing technologies — debarking and chipping


2. Densification technologies — wood pellets, briquettes

3. Direct thermal combustion technologies — direct thermal combustion for heat and power, including small-scale combined heat and power systems

4. Thermal-chemical conversion technologies — chemical conversation technologies including gasification and pyrolysis. These technologies can also produce useful energy directly but can also be used to produce useful bio-products including bio-oils, syngas and biochar.

The appropriate choice of a bioenergy technology depends highly on the waste type (e.g. sawdust, hog fuel) and the quality (moisture content, density, particle size, contamination) and quantity of biomass available. Understanding the waste stream and its characteristics and also understanding current on-site space availability and potential operational / management impacts are also key factors in selecting the most appropriate technologies.

1.3.2 Bioenergy products and applications

This work explores both bioenergy products that can be manufactured and sold into markets by small-scale forest operators, and also applications from bioenergy technologies.

The different products explored in this study are:

• Wood chips — chips made from chipping waste wood to a specific dimension or specification.

• Wood pellets — compressed pellets derived from sawdust and other finely chipped residues used for thermal heat applications.

• Wood briquettes — larger compressed bricks of biomass used for thermal heat applications.

• Bio-oils —oils (also called pyrolysis oils) derived from pyrolysis technologies that can be used as replacement oil.

• Biochar —char derived from pyrolysis technologies that can be used in solid form for carbon sequestration and as a soil amendment for increased soil productivity.

The different applications included in this study are:

• On-site heat generation and usage — the production of thermal heat for local — for space-heating, domestic water heating or process heat (i.e. kiln drying, greenhouses)

• District energy heat distribution — the production of hot water for underground district heating applications. District heating is effective is there are multiple buildings or processes that have a heat demand. These systems would be geared for larger systems and small-scale operators that have higher volumes of waste wood.

• On-site power generation and usage — the production of electricity from non-steam electricity generation technologies. Electricity could be used for on-site usage or connected to the grid with a purchase agreement from a local utility.

Selection of the products and applications researched was guided by the following criteria:

• Applicable to small-scale forest operations — the capacity (size of the system) or

production rate of the system matches the volume of waste wood available.


• Applicable to the types of waste wood produced — technologies are suited to the

types and characteristics of wood waste produced (i.e. sawdust, slabs)

• Technology readiness — commercial or near-commercial technologies that are for the

most part available in Canada

• Potential market — either on-site, locally within the Kootenay Region or to external

markets outside the West Kootenay region.1

1.4 Technology readiness

Technology readiness can be challenging to define and equally challenging to identify. Technologies are continually evolving and improving — and companies that sell these systems sometimes make exaggerated marketing claims. Figure 1 shows the typical life cycle of technology readiness, starting from research and development through to commercialization. Even if a technology is considered technically mature, the specific on-site operational and maintenance requirements can be high, making the economics of the overall project challenging and the readiness of the technology questionable.

Figure 1. Technology readiness scale2

1 The potential market of a product is not explored to any extent other than gaining an appreciation that the product could be sold locally or regionally. 2 Adapted from https://cfs.nrcan.gc.ca/selective-cuttings/51


In the context of this work, a bioenergy technology can be considered commercial when several systems have been successfully deployed with proven performance and strong project financials (i.e. not requiring government support). Near-commercial systems are those that are likely to become commercial in the coming few years; a few systems have been deployed and tested at a commercial scale. This is, however, a very subjective statement. Transitioning from near-commercial to commercial can often take years; it is not uncommon for companies to claim their systems are commercially ready, only to see some successes but also some failure.

This study acknowledges the challenges with categorizing technologies as commercial and near-commercial. It focuses on commercially-proven technologies, but also includes near-commercial technologies that appear to be available in Canada (either Canadian technology or technology developed outside Canada but available in the Canadian market through Canadian vendors).


Figure 2 summarizes the current technology readiness for the various bioenergy technologies discussed in this report based on a qualitative assessment of materials reviewed.

Figure 2. Bioenergy technologies — commercialization scale

Pre-processing, manual densification and direct thermal combustion are the most commercial technologies. Of note is the Organic Rankin Cycle types of systems that are not specific to the biomass industry. These ORC systems work on waste heat for a variety of applications and scenarios with some companies offering biomass-tailored products. It is the remaining technologies – thermal chemical conversion (gasification and pyrolysis) that are in the early and near-commercialization stage; many companies are working on commercializing systems specific to niche applications and it is the opinion that there is ways to go before the number of successfully deployed cases show case these technologies as commercially viable.

1.5 Technologies out of scope

A few technologies are not considered in this work, but are worthy of mention:

• Steam-based direct combustion (Rankin systems) — Although commercial technology, these systems are considered large-scale (10 MWe up to 300+ MW) and require large, continuous volume of waste wood. They also must be operated by a steam and power engineer (an occupation highly regulated in Canada) making them expensive, complex systems.

• Hot air engines (Stirling or Ericsson) – Although research into Sterling and Ericsson engines is well advanced in Europe, most companies working on them aren’t focused on North America. Many of the technologies are still in the early demonstration stage, and are not yet commercial.

• Torrefaction technologies — This technology (also referred to as mild pyrolysis or partial carbonization) is similar to pyrolysis, but operates at a lower temperature (400°C–


600°C ) and focuses on the char-like product produced, not bio-oil. Commercialization of small-scale torrefaction systems is behind that of pyrolysis systems.

• Production of liquid biofuels through gasification — Gasification can be used to produce ethanol, methanol or hydrogen. These technologies are at best pilot or demonstration with very few commercial plants, and current examples are large facilities.

• Anaerobic decomposition — The anaerobic decomposition of waste material that results in the production of methane which in turn can be used to generate electricity is more geared towards technologies that deal with non-woody biomass (i.e. agricultural waste).

1.6 Recent research and available resources

Below is a summary of some of the more recent research papers that were used in the development of this report.

1. Small-scale Biomass CHP Technology Commercialization in Canada – A very recent report commissioned by Natural Resources Canada not yet publicly available. It is a thorough report that looks at small-scale (< 3 MWe) commercial and near-commercial combined heat and power bioenergy technologies. The report highlights companies and discusses the challenges these technologies have faced in reaching commercialization and why some have not penetrated Canada. The technologies in the 1–3 MW higher range might be suitable for medium-size forestry operations but will be too large for the smaller forestry operators in the West Kootenays, who don’t produce enough waste wood to satisfy the demand of these larger systems.

2. Small-Scale Biomass District Heating Handbook – A report3 produced in 2014 by the Community Energy Association and written for local governments and First Nations that are interested in the developing a business case for the development of a biomass district heating system.

3. Technology Roadmap: Bioenergy for Heat and Power – The International Energy Agency released this report4 in 2012 that identifies technology goals and key actions for governments that must be undertaken to expand the production and use of bioenergy systems.

4. Biomass Availability Study for District Heating Systems – A report5 published in 2012 by EnviroChem Services Inc. for the B.C. Bioenergy Network that provides information on biomass district heating systems and biomass supply specific to the Metro Vancouver and Fraser Valley districts.

5. An Informational Guide On Pursuing Biomass Energy Opportunities and Technologies in

British Columbia: for First Nations, Small Communities, Municipalities and Industry – A

3 http://www.toolkit.bc.ca/Resource/Small-Scale-Biomass-District-Heating-Handbook 4 http://www.iea.org/publications/freepublications/publication/bioenergy.pdf 5 http://www.bcbioenergy.ca/wp-content/uploads/2012/02/Complete-Biomass-Availability-Study-Feb-7-2012-Final.pdf


report6 produced in 2008 for the B.C. Ministry of Energy, Mines and Petroleum Resources by BIOCAP Canada that provides information the various states of biotechnologies (anaerobic digestion, combustion, gasification, pyrolysis, lignocellulosic ethanol and biodiesel), funding sources and the considerations for the types of feedstocks required for these technologies.

6 http://www.energyplan.gov.bc.ca/bioenergy/pdf/bioenergyinfoguide.pdf


2. Background information

2.1 Biomass energy

Biomass energy (bioenergy), in the simplest terms, is derived from recently-living organic matter. Biomass can come from wood, agriculture waste products or municipal waste, but the biomass considered in this report is forest-based biomass resources that are byproducts from small-scale forestry operators — sawdust, bark, shavings, offcuts, etc. Further details on these byproducts are discussed in Section 2.5.3.

All forest-based biomass contains a certain amount of energy that can be used for a variety of purposes. The amount of energy contained in biomass is often expressed in gigajoules (GJ) of energy7. To make comparison possible, the amount of energy in a biomass resource is often expressed in bone-dried-tonnes (BDT) which is the weight of a tonne of biomass with very little water or moisture (~ 5%). As a rough rule-of-thumb, a BDT of forest-based biomass is equivalent to approximately 2.5 m3 of green biomass. The energy content of a BDT of forest-based biomass varies slightly depending on the species of wood, the percentage of bark and can range from 14 to 25 GJ / BDT. For the purpose of this research, a value of 18 GJ / BDT has been selected for simple energy calculations.

When using biomass feedstocks with bioenergy technology, the amount of usable GJ of energy depends on the characteristics of the biomass (predominantly moisture content, and to some extent, the amount of white wood versus bark), the type and efficiency of the conversion biotechnology, and the number of byproducts derived from the biotechnology. For example, a high-efficient direct thermal combustion system (80% efficient) that uses hog fuel which has 50% moisture content will only produce 6–8 GJ of heat energy. The rest of the energy in the hog fuel essentially goes to vaporizing the moisture in the wood and there are further losses as a result of the efficiency of the system.

2.2 Bioenergy in B.C.

B.C. is blessed with abundant forests and a sustainable forest industry. Although the primary market for forestry in B.C. is traditional products (timber, pulp and paper), there has been an increase over the years in forestry operations producing energy from waste and other biomass materials. Most significantly is power generation by large-scale sawmills that utilize their operational waste. Through BC Hydro’s Call for Power, the sawmill industry has been able to diversify and produce not only timber / pulp and paper, but also power for behind-the-fence operation, as well as producing power that is sold to the grid. Natural Resources Canada (NRCan) produced a report (in conjunction with the Forest Products Association of Canada) in

7 The energy in one BDT of biomass (assuming 18 GJ / BDT) = the energy content of 2.95 barrels of oil7 (BOE) = 5 MWh = 17.1 million BTU (MMBTU)


November 2005, looking at the opportunities for the B.C. biomass industry.8 The report looked at the volume of wood residues across Canada, business-as-usual management of waste wood and potential future uses. The research estimated that a surplus of 1,814,955 BDT of wood residues were being disposed of either in managed wood residue landfills or by incineration in B.C. alone. Although ten years old, the report provides insight into the volume of waste wood that was underutilized. Today, many large industrial wood pellet facilities have been introduced to take advantage of this waste resource, and the wood pellet industry in Canada has been very successful. There have been several more large-scale facilities commissioned in recent years that are taking advantage of mountain pine beetle damaged wood and roadside residues. Today, there are about 13 wood pellet plants in B.C. and four more proposed, with the average-sized plant producing 150,000 BDT/year9. There are also other bioenergy facilities producing biodiesel and other bioenergy products.

There are also several smaller-scale facilities producing bioenergy heat from waste resources, and these are increasing.10 The City of Revelstoke is an excellent example of a municipality that has developed a community bioenergy project utilizing waste from a local sawmill.11 The facility provides energy to nearby buildings through a district energy system.

Figure 3 summarizes some of the main bioenergy projects in B.C.

8 Natural Resources Canada, Estimated Production, Consumption and Surplus Mill Wood Residues in Canada —

2004. http://cfs.nrcan.gc.ca/pubwarehouse/pdfs/25989.pdf 9 http://www.pellet.org/images/CBM_Pelletmap2012FINAL.pdf 10 NRCan has recently compiled this information but it is not publically available 11 http://www.revelstokecommunityenergy.ca


Figure 3. Bioenergy projects in B.C.

Source: B.C. Ministry of Energy and Mines and Responsible for Core Review12

2.3 Bioenergy in the West Kootenays

Commercial bioenergy technologies deployed in the West Kootenays are very limited; there are only a few installed systems (i.e. Fruitvale (Kootenay Tonewood) and Castlegar (Fire Attack Base)). There are other examples in the East Kootenays and more throughout B.C. The Waste Wood to Rural Heat project13 is focused on providing technical and business model support for parties interested in bioenergy (heat focused) systems utilizing waste wood.

For the past two years, Nelson Hydro and the City of Nelson have been exploring the feasibility of a district energy system using renewable energy. In October 2014, Nelson Hydro stated that a biomass district energy biomass thermal plant with wood chips as the primary feedstock is the best option when compared to geothermal. Further investigation is being conducted on the project financials. If considered economically viable, the project could require a significant amount of wood chips every year and would displace natural gas as the main fuel for heating. A

12 Bioenergy Sector in British Columbia, Ministry of Energy and Mines and Responsible for Core Review http://www.empr.gov.bc.ca/EAED/InvestmentInfo/Documents/BioenergySector25May2010.pdf 13 www.woodwaste2ruralheat.ca/


feasibility report14 prepared for the City in 2011 suggests that a district heating system would require anywhere between 3,000 and 10,000 BDT of biomass per year.

2.4 Small-scale forest operations in the Kootenays

The West Kootenays are home to well over two dozen local sawmills, community forests and specialty wood manufacturing shops. The sector is diverse, with small- and medium-size sawmills producing timber products for local / regional markets and some producing wood products for the U.S. and other international markets.

Most small-scale operators have surplus waste wood that comes with a financial and management cost to their operations. The business-as-usual scenarios for current waste streams at small-scale facilities vary and include:

• Giving away – Some operators promote and give away their waste wood for firewood, fencing, animal usage and sometimes hog fuel usage. Giving away this resource means operators lose the economic value of this waste wood and sometimes it is even a management / economic burden to the operation.

• Pile and burn – Open burning of the waste wood (when air regulations permit) is a way to remove the waste stream from site. The environmental implications of this activity include ash production, air quality concerns, greenhouse gas emissions and fire management / risk.

• Transporting to larger bioenergy facilities – Sawdust or other waste streams are sometimes transported to larger bioenergy facilities that have the capability of utilizing these wastes. There is typically a financial cost to the operations that transport their waste and, similar to when they give wood away locally, operators lose the economic value of this waste wood.

A surplus of waste wood was one factor contributing to the closure of the Gold Island Forest Products sawmill; they could not properly deal with their sawmill waste. Small-scale forest operators are in good position to utilize their waste woods from harvesting or milling — they have a reliable, steady flow of residues, skills and experience with handling biomass, and equipment (trucks, forklift, storage) and management in place to potentially handle another biomass product line.

2.5 Wood wastes

2.5.1 Volumes

The different small-scale operations in the West Kootenays all produce a variety of waste wood types and annual volumes. The biotechnologies and applications focused on in this research are applicable to operators that generate in the range of several hundred BDT to several thousand

14 Blackwell and Associates, 2011. Biomass Feedstock Assessment – To Support the City of Nelson District Energy,

System. Confidential


BDT of waste wood per year. A report completed for the City of Nelson15 and Area E of the RDCK16 suggests there are approximately 15 small-scale forest operations within the region that volumes of waste wood per year vary but all produce less than 7,000 BDT / year and many producing well under 1,000 tonnes / year, summarized in Figure 4. For the ten operations that produce less than 1,000 BDT / year, the average is 511 BDT/year. The composition of the waste wood varies; hog fuel (including bark) and sawdust are the dominant types of resource (making up a combined 88% of the feedstocks) with shavings and slabs making up the remainder. This report focuses more on the businesses that produce waste wood on the lower end of the volume spectrum, ~ 1,000 BDT / year.

Figure 4. Waste wood volumes — small-scale forest operators in the Kootenays

Cumulatively, 23,101 BDT / year of waste wood is generated by these 15 small-scale operators. Further information provided in the City of Nelson report suggests approximately 60,000 BDT / year is produced within 40 km of Nelson and an additional 50% of that amount within the West Kootenays.

2.5.2 Wood energy comparison

To gain an appreciation of the amount of energy in various amounts of waste resources, Table 2 provides approximate energy content for a few example volumes and types of waste wood (assuming 18 GJ / BDT). For example, if an operation was producing 500 tonnes / year of waste sawdust, the energy in that sawdust is equivalent to 1,180 barrels of oil — a fairly substantial energy source. The usable energy will vary depending on conversion technologies and efficiencies.

15 Blackwell and Associates Ltd., Biomass Feedstock Assessment to Support the City of Nelson District Energy

Study (2011). 16 Renner, Cathro, Blackwell. Bioenergy Feasibility Study for Area E of the Regional District of Central Kootenay (2011).


Table 2. Approximate energy content for example waste resources

2.5.3 Waste wood types

The main species of trees harvested in the West Kootenays and hence the species of the waste wood include Western red cedar, Western hemlock, Douglas fir, Lodgepole pine and Western larch. Waste woods specific to the forest industry in the Kootenays are predominantly hog fuel, sawdust, shavings and slabs (also called off-cuts or cants). Other sources include rejected or unmerchantable trees (reject logs) from logging that do not end up being milled because of deficiencies in the wood.

Table 3 summarizes these main feedstocks. Over half of the feedstock is hog fuel (54%) followed by sawdust (35%), which thus make up the majority waste streams.

The main characteristics of the waste resource that that are important for bioenergy applications include moisture content, heating value, bark/ash content, density and particle granularity. Most feedstocks vary in these main characteristics, so providing a waste wood stream that has consistent characteristics is one of the most challenging aspects of bioenergy applications.

Cedar is the one species that presents a problem for bioenergy applications. The bark is quite stringy and if used in direct thermal combustion systems, it can get caught up in the auger systems. The bark also tends to pick up a lot of sand/dirt that can contaminate the biomass resource and also be hard on chipping equipment.

The combustion of bark is primarily what creates ash, which is the non-combustible inorganic residue of biomass. Clean white wood contains very little ash (0.5%) and bark contains higher amounts of ash (up to 4%). During the combustion of bark, the minerals contained within can stay in the combustion chamber and result in clinking. These minerals melt at around 95°C and stick inside the combustion chamber, resulting in a yellow grey deposit that forms into clumps of slag. This slag hardens and is very difficult to remove. There is an advantage to removing the bark from the waste resource if possible — the resulting material will be of better use for producing chips or using in a combustion boiler. If it is possible to remove the bark, combustion improves and particulate matter emissions decrease. This is discussed more in the following chapters.

Type

Moisture

content

Volume

(BDT / year)

Energy

available (GJ)

Barrel of Oil

Equivalence

50% 500 4,500 738

50% 1,000 9,000 1,475

50% 2,000 18,000 2,951

20% 500 7,200 1,180

20% 1,000 14,400 2,361

20% 2,000 28,800 4,721

40% 500 5,400 885

40% 1,000 10,800 1,770

40% 2,000 21,600 3,541

Hog fuel

Sawdust

Offcuts


Table 3. Characteristics of biomass waste resources

Biomass resource

Proportion of feedstock

Description Typical characteristics Best bioenergy applications

Hog fuel 54% Industry slang for the lowest value type of biomass resource: a course mixture of bark and other mill residues including sawdust. Sometimes produced through the use of a mechanical hog shredder or grinder.

Hog fuel has been used in the past for fuel in bioenergy applications, or sent directly to landfill, openly burned, used for animal feed and landscaping (if processed).

Often large fragments (larger than wood chips) that are very non-uniform in size, wood type, moisture content, etc.

Typically include a high percentage of bark, but can also contain other mill residues including sawdust and shavings.

Moisture content typically quite high around 50%.

Wood chipping

Direct thermal combustion

Sawdust 35% Produced from milling and planing of dimensional lumber

Typically free of most contaminants.

Usually finer grain.

Dusty and can be messy. Avoid using in public applications.

Reasonable moisture content (~20–30%), but can rapidly lose moisture content during storage.

Difficult to use by itself for bioenergy applications except possibly for the production of wood pellets.

Can be mixed with other biomass sources for direct thermal combustion or gasification systems

Slabs / off-cuts / cants

5% The outside piece cut from a log when squaring timber, log ends, rejected boards.

Usually contains both bark and white wood.

Medium-high moisture content (~30–40%)

Cordwood boilers

Wood chipping

Shavings 7% Produced from planing — typically larger than sawdust

Low moisture content (10–20%) Difficult to use by itself for bioenergy applications except possibly for the production of wood pellets.

Can be mixed with other biomass sources for direct thermal combustion or gasification systems


2.6 Financials

2.6.1 Financial value of products derived from waste wood

As an approximation only for the purposes of this report, the average purchase price of unprocessed biomass feedstocks currently has a wide range — from $50–$150 / BDT.17 Upgrading waste biomass to a usable product increases the price.

A realistic estimate of the economic value of waste wood is $40–$60 / BDT. Transportation will be the most significant cost associated with biomass feedstocks (around $10–$30 / BDT), with higher costs associated with higher moisture content in the feedstock. But at even $50 / BDT, the economic value of the 23,101 tonnes of waste feedstock could represent $1,155,050 of value to small-scale forest operators.

Producing higher value products like wood pellets would increase the economic value to about $300 / tonne, which is the current cost of delivered residential wood pellets in Alberta.

2.7 Biotechnologies categories — further details

This section provides more detail on the four main bioenergy technologies.

1. Biomass pre-processing — the processing of waste biomass into a more usable, higher value material so the product can be sold into markets or used more efficiently with certain technologies. This category includes debarking wood to separate more valuable white wood from bark and chipping of biomass so it is in a more usable or marketable form. Passive drying techniques for reducing moisture content are lightly explored; however active drying systems are not discussed as they are likely cost prohibitive for small-scale forest operations.

2. Biomass densification — the densification of biomass resources resulting in the product having a much higher energy content. This category includes wood pellets and briquettes or pucks. This category does not look at any carbonization or torrefaction process as they are considered too pre-commercial for this research.

3. Direct thermal combustion — the direct aerobic combustion (combustion in full oxygen) of biomass to produce heat, power or both. Heat-only is the simplest combustion technologies available and should be considered when there is an on-site heat demand (space heating, water heating, process heating) or even potential for a small district heating system. Electricity generation systems researched in this report are limited to organic Rankin cycle (ORC). On-site electricity production should be considered if the operation is connected to the local grid and the local utility supports a net metering program.

4. Thermal-chemical conversion — the oxygen-restricted combustion of biomass under various conditions (amount of oxygen, speed of combustion, various temperatures) to produce bio-products (syngas, biochar or bio-oils) or a combination of both.

17 http://ctcg.org/wp-content/uploads/2011/07/Summary-Guide-to-Technologies-Considered.pdf


Figure 5 graphically represents the bioenergy technologies, products and applications researched in this report. There are a few different pathways to arrive at end products / applications — the best pathway depends on the type of biomass and the best suited technology for the forest operations, which is discussed further in this report.


Figure 5. Bioenergy technologies, products and applications


2.7.1 System sizes and capacity

Bioenergy systems are offered in many sizes and capacities, but only a subset are suitable for the lower volume of waste wood generated at small-scale forestry operators in the region.

Applicable system size or capacity depends on the application or the product being produced; it could be based on the amount of wood chips produced, the heat or electricity demand, or the amount of bio-oil or biochar produced.

Table 4 provides some high-level guidance on appropriate capacity ranges for bioenergy technologies based on the range of available wood waste.

Table 4. Appropriate bioenergy technology capacities based on available waste wood

Technology Annual waste biomass (BDT / year)

Approximate capacity

Assumed efficiency

Chipping, pellet and briquette production

100 104 kg / hour

N/A 500 521 kg / hour

1,000 1,042 kg / hour

2,000 2,083 kg / hour

Direct combustion for heat

100 208 kW

80% 500 1,042 kW

1,000 2,083 kW

2,000 4,107 kW

Direction combustion – ORC

100 26 kW

10 – 15% 500 130 kW

1,000 260 kW

2,000 521 kW

Gasification with ICE

100 65 kW

20 – 30% 500 326

1,000 651

2,000 1302


3. Pre-processing and densification technologies

This section provides information on the first two bioenergy technology classifications: pre-

processing and densification of biomass to higher value products.

Pre-processing and upgrading technologies improve feedstock characteristics (particularly moisture content, uniformity and cleanliness) to make handling and storing more efficient and create a more usable feedstock for thermal conversion technologies. Densification technologies also improve biomass characteristics to minimize transportation costs (by improving energy density) and provide a feedstock that has consistent characteristics — a key quality for optimal performance of bioenergy technologies.

These technologies along with a brief description and potential applications / products are listed in Table 5.

Table 5. Pre-processing and densification technologies

Technology Description Application / Product

Pre-processing Debarking and chipping. Wood chips for on-site heat/power use

Selling wood chips commercially

Densification Compressing waste wood into pellets or briquettes.

Manual densification18

increases the energy content of the product and produces a consistent quality feedstock. Densification is an economically value-added process.

Selling wood pellets or briquettes to residential or commercial market (likely residential for both pellets and briquettes)

3.1 Pre-processing — debarking

Opportunities for debarking are applicable only to milling operations that process whole logs; the use of debarkers is currently not common amongst small-scale forestry operations. The typical operation involves sawmill operators cutting linear slabs from the log to remove the bark, which sets the stage for cutting timber. The slabs that are produced are a combination of the outside bark but also a certain amount of the white wood, as shown in Figure 6.

Debarkers could be used to strip cut logs of unnecessary bark which could have direct benefit for the milling application and bioenergy applications. Clean logs with no bark would make it easier to produce timber and also maximize timber output, thus increasing the economics of the sawmill operation directly. The benefit of debarking is that it separates the white wood from the bark, which typically has more contaminants (dirt, rocks). Although bark has a higher energy

18 As opposed to chemical thermal densification (i.e. torrefaction) which is not discussed in this report


content, combusting it results in higher ash and air emissions (particulate matter). It also has negative impacts on the performance of boilers (from slagging and fouling19) and hence requires more maintenance. Burning waste wood that had high percentages of bark in beehive burners was common practice until they were banned in B.C. and turning back to burning bark could be viewed as a step in the wrong direction.

Figure 6. Slabs from a milling operation, showing white wood removed along with bark

3.1.1 Technology description and maturity

Debarkers have been around for several decades. There are four main types of debarkers: ring debarkers, drum debarkers, rosserhead debarkers and flail debarkers. Most are quite large and likely not applicable for small-scale forest operators, but are included here for completeness.

• Drum debarkers — These debarkers are the largest type; they have large drums that rotate and tumble the log in a circular motion. This tumbling action strips off the bark when the log rubs against the drum walls. Drum debarkers work well on large quantities of smaller diameter logs. They could be used in bioenergy applications where whole log chipping is the focus but they required significant space as the drums are usually quite large.

• Ring debarkers — Smaller systems where the logs are individually fed into the debarking system through a centering infeed. Inside the debarker, pressurized spike/knife rolls (typically sets of three) strip the bark away as the log moves forward. Ring debarkers are primarily used for high-capacity sawmills and specifically target softwoods.

• Rosserhead debarkers — These debarkers rotate the log in a stationary cradle. A cutting head passes along the length of the rotating log, cutting away the bark. Rosser head debarkers are primarily used in low capacity systems and are best suited to hardwoods.

19 Slagging and fouling is the formation of deposits on heat transfer systems and is one of the main challenges of biomass combustion systems


• Flail debarkers — Less common, these debarkers are equipped with chains or other flexible material mounted on a rotating shaft and forcibly whipped against the log, loosening and removing the bark from the log. These systems are most commonly utilized in remote bush chipping operations.

3.1.2 Biomass feedstock requirements and considerations

Logs should be delimbed (including the top of the tree), free from any protrusions that would impede rotation or feeding the log through the debarker, and cut into sections. Drum debarkers can take longer length logs, while ring and rosserhead debarkers require logs to be cut in shorter section (commonly 8–12 feet). The maximum diameter of logs depends on the type of debarker; 2 inches is minimum, with some debarkers able to debark logs up to 40 inches in diameter.

Most tree species can be debarked, but different debarking systems are typically used for hardwood versus softwood. Cedar trees are very difficult to debark because of the bark’s stringy nature.

3.1.3 Applications and products for small-scale forest operations

Debarkers are relevant only to sawmills that are processing whole logs. They could be a viable investment if there is space and the process can be integrated into the current operations, and the sawmill operation is interested in pursuing a bioenergy technology.

With the bark removed from the logs, milling could produce slabs that have little to no bark on them; this would facilitate the production of white wood chips, a preferred resource for some chip boilers. Leftover bark could be used for non-energy applications (animal bedding, landscaping). As mentioned above, using bark, even in the more advanced biomass boilers today, is likely not an acceptable choice due to high smoke and air pollution. An alternative choice would be to divert the bark to a composting facility. The Slocan Integral Forestry Cooperative, based in the Slocan Valley, conducted a feasibility study on utilizing waste wood for a composting program.20

3.1.4 Further considerations

Ring debarkers are simple to operate and so do not require a dedicated operator. Rosserhead debarkers, however, have complex feed patterns and a dedicated operator is often required.

Debarkers can be stationary, portable or come integrated with a truck for easy transportation. They are typically diesel powered, but newer electric models are being introduced. Most debarkers researched are larger machines; only a few were considered small enough to be appropriate for small-scale forestry operations, the Morbark 640 being a good example.

Debarkers, especially because of the infeed and outfeed conveyers, can be quite long. Space will definitely be a requirement if a debarker is to be considered.

20 Feasibility Study – Kootenay Biomass Recovery Initiative, November 2012


As discussed above, adding a debarker and bioenergy application to a small-scale forestry operation will only be feasible if it would improve the economics and assist in diversifying the products.

3.1.5 Example technologies

Only a few debarkers were found that seem appropriate.

Morbark 628 and 640 (http://www.morbark.com )

The Morbark 62821 is a larger rosserhead debarker with a debarking production rate of 60 feet/min. It can handle both hardwood and softwood logs 44 feet long and widths between 6 and 28 inches. The debarker can be electric or diesel (100 HP maximum electric, 140 HP diesel). It has a 20-foot trough infeed conveyer and a 20-foot trough output conveyer, making it quite a long debarker.

The Morbark 64022 is a slightly larger system that also accepts softwood and hardwood and has a higher feed rate of 100 feet/min. The 640 also comes in electric and diesel configurations. It is one of the more commonly used debarkers for small-scale operations.

Figure 7. Morbark 640 debarker23

Nicolson sliding ring R2 (http://www.debarking.com)

The Nicolson low speed sliding ring debarker is one of the newest additions to their product line. Hydraulically driven, it is a three-head ring debarker that can debark logs up to 38 inches.

21 http://www.morbark.com/wp-content/uploads/628-Debarker.pdf 22 http://www.morbark.com/wp-content/uploads/640-Debarker.pdf 23 http://www.morbark.com/wp-content/uploads/640-Debarker.pdf


Figure 8. R2 ring debarker24

DK Spec Timberfox (http://www.dkspec.com)

The Timberfox high-speed ring debarker can handle logs up to 18 inches in diameter and can process logs at 400 feet/min. It is an electrically-driven system.

There are many older ring debarking products available in B.C. through Canadian Mill Equipment, including Cambio and Nicolson products.25

3.2 Pre-processing – chipping

This section provides information on wood chippers and shredders. There are other technologies including grinders and hammer mills that reduce biomass to smaller sizes, but the quality of the material produced from these other technologies is often not suitable to make chips for bioenergy applications. Grinders (and some shredders) are usually employed to produce hog fuel from various waste wood resources.


Many different types of wood chippers/shredders are on the market with a range of purposes. The most common use is to reduce biomass volume and facilitate better handling of biomass (i.e. chipping up municipal waste – tree pruning, downed trees). Since the end product is not generally used for bioenergy, the quality and consistency of the chip is not important.

However, for most bioenergy applications that use chips, the physical characteristics of the chips are extremely important: moisture content to ensure correct combustion/air mixture, white wood

24 http://www.debarking.com/brochure/r2.pdf 25 http://www.cdnmillequip.com/category/45/Debarker++Ring


versus bark for ash and air emissions, and physical size to ensure the feed system (typically an auger feed) does not jam and the overall system runs smoothly. Small-scale bioenergy boilers (< 300 kW) usually require smaller wood chips with uniform size, while larger bioenergy boilers can take bigger chips with larger variability in the quality of the biomass (moisture content, contaminants) as they are able to adjust their operation to deal with this variability.

It is beneficial to ensure that any chipper considered for a bioenergy application can produce chips that meet the European CEN/TC 335 standard or the ISO TC 238 standard. These standards define acceptable dimensions, moisture content and ash content (amount of bark); using a standard is a simple way to communicate requirements to potential customers. Although the standards are recent and are more in use in the EU than in North America, bioenergy manufacturers are moving toward meeting them. The Biomass Energy Centre in the U.K. produced a chipper review for small-scale chippers26 and is a good resource. This review compares chips produced by ten small-scale chippers against the CEN 355 standard.

There are three main different types of chippers. The choice of chipper and quality of chip produced is important if the chips are going to be used in an auger feed system.

• Disk chippers – Disk chippers use a large-diameter steel disk with attached blades at set angles. The disk rotates at high speeds and the blades cut regular chips from the biomass that is fed in through a roller system. The size of the chips produced is determined by the number of blades attached to the disk, the rotation speed of the main disk and the rate the feedstock is fed into the system.

• Drum chippers – Similar to disk chippers, drum chippers use large rotating drums with hardened blades. Chip size is determined by the drum speed, number of blades and the rate the feedstock is fed into the system.

• Screw chippers – Screw chippers use a rotating, helical screw thread with a hard cutting edge. The rotating screw thread itself draws the feedstock into the chipper. Screw chippers produce some of the highest quality chips with good output and are generally quieter than disk/drum chippers, but they require significantly more power.

Chippers can be hand fed or crane fed. For the volume of wood waste at operations in the Kootenays, hand-fed chippers will be adequate.

For possible chipping of waste wood at small-scale facilities here in the West Kootenays, small-scale chippers (< 100 m3 per hour of chipping) are likely adequate; small-scale chippers are geared towards hog fuel, branches or slabs and small diameter non-merchantable trees.


Wood chips range in size, wood species, moisture content, bark content and impurities (dirt, rocks). Some bioenergy combustion systems can take a wide range of wood chips, but most and especially smaller systems have specific feedstock requirements for uniformity and consistent

26 http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/RESOURCES/REF_LIB_RES/PUBLICATIONS/TECHNICAL_DEVELOPMENT/IPIN%200208%20SMALL%20SCALE%20CHIPPERS%20CEN.PDF


characteristics of the wood chip. This can make chip production difficult and expensive, but is key for efficient operation of the system.

Better quality wood chips are derived from waste wood that has little or no bark; bark creates ash and can cause buildup inside the combustion chamber. Hence, chipping waste slabs or cants that have bark may be less than ideal. A possible solution to this may be to employ a debarker within the main operations of the facility (as discussed in Section 3.1), but the viability of that depends on the benefit of integrating a debarker into the main operations as well. Typical and viable feedstocks for producing wood chips include hog fuel, debarked slabs / offcuts, or slabs that have very minimal bark. Small diameter trees that have been harvested and have defects or are unmarketable are possible feedstocks, but would require larger chippers. Generally, most wood chip boilers require chips smaller than 3 inches in diameter, but small commercial systems have even tighter and more restrictive fuel specifications (typically around 10 mm3). Chipping wet biomass (moisture content higher than 60%) can be problematic and is best avoided.

3.2.3 Applications and products for small-scale forest operations

The best application for introducing an on-site chipping application is the chipping of hog fuel or slabs for on-site usage in a chip boiler. Moisture content in chips can be as high as around 60% (passive drying when done correctly will typically not get moisture content of chips below 20%) making the transportation costs of chips usually prohibitive. Chip boilers could be used for space heating or process heat (kiln drying). If there are a high percentage of unmerchantable trees that are harvested or a high rate of defects in milled wood, there might be opportunities for whole tree chipping. The Bandit series of chippers includes whole tree chippers.

Alternatively, clean wood chips that meet certain specifications (dryness, bark content) could be sold as a commodity to a local bioenergy system or company that requires a wood chip feedstock for direct thermal combustion or gasification technologies but doesn’t have the resources, infrastructure and/or interest to produce the chips themselves. A local market would be key because of the relatively high moisture content of the wood chips and the associated cost of transporting them. Even with a local market, some innovation and cost barriers would need to be removed to make the financials viable. A reasonable estimate of the cost of wood chips is $40–$60/BDT.

Nelson Hydro, the electrical utility owned by the City of Nelson, has been investigating the feasibility of a district energy system in the downtown core using renewable resources. Current research suggests that a biomass system using wood chips is the most economical system (compared to ground-source heat pump geoexchange systems) that would satisfy their needs. Analysis is ongoing and a decision is forthcoming whether a wood chip biomass system is financially viable. It is expected that the district heating system would require 3,000–10,000 dry tonnes of biomass per year27 depending on the size and number of buildings connected. This might be an excellent opportunity for a small-scale forest operation that has waste wood and is interested in researching the viability of a business to supply the City with wood chips. The City and interested parties would have to work together to ensure that the specifications of the wood

27 Blackwell and Associates, 2011. Biomass Feedstock Assessment – To Support the City of Nelson District Energy,

System. Confidential


chips required by the bioenergy system can be met; establishing a fuel specification contract with the buyer is extremely important so the quality of the delivered fuel is understood by all parties.

Yet another possibility is investigating whether several forest operations could work together in a co-operative to combine their waste resources in an aggregation facility, collectively meeting the needs of a larger client. A co-operative model would allow small-scale forest operations that don’t have enough waste wood by themselves to work together and share the costs of the facility including transportation. Different waste resources (sawdust, hog fuel) could also be combined to produce a desired blended feedstock. A Pembina research intern was hired in the summer of 2013 through the Pacific Institute for Climate Solutions (PICS) and researched the viability of a wood waste aggregate model.28

The Wood Waste to Rural Heat (WW2RH)29 project is a two-year funded project looking at providing feasibility and business case studies for waste bioenergy applications in the Kootenay region. It may be possible to access this resource to discuss the viability of producing and selling wood chips in the local market and what bioenergy-for-heat projects may be in development that would require a stable supply of wood chips.


Chippers can also be noisy, so proximity to operations or other buildings should be taken into consideration. Regular maintenance is especially important so the chipper can produce wood chips to the same specification.

Chippers can be powered using diesel/gasoline or electricity. Diesel powered chippers are less environmentally friendly, consume a lot of diesel and are generally more maintenance intensive than electric driver chippers. There is also the potential of diesel spills and soil contamination with diesel-powered chippers. Bandit Technologies (example below) is one company that has a product line of electrically driven chippers.

If a small-scale forest operator is going to invest in a chipper, a mobile chipper that can handle both mill waste as well as logging slash is likely the more economical choice.

Chip Storage

On-site storage of the wood chips will be important to maintain the quality of the chips, keep the chips free of contaminants if they are to be stored for a great length of time (> 2 or 3 months) and support drying. Passive drying techniques as simple as tarping and covering the biomass can be adequate30, but the volume of the wood chips will start to decrease over time as natural decomposition sets in. Good airflow is also very important to reduce the moisture content and ensure mold does not grow. If piling the wood chips, a maximum height of 8 to 10 metres31 is

28 This PICS research is available upon request 29 http://www.woodwaste2ruralheat.ca 30 Research being done by FPInnovations show that there is the potential to reduce moisture content by 10 to 30% by properly piling and covering the biomass. - http://www.canadianbiomassmagazine.ca/content/view/4579/60/ 31 www.biomassenergycentre.org.uk/portal/page?_pageid=75,17827&_dad=portal&_schema=PORTAL


suggested to limit decomposition and possible spontaneous combustion. High temperatures can be reached within the pile during decomposition and there is a real risk of fire. Smaller stacking can reduce the possibility of mold. FPInnovations has been conducting research on optimal biomass piling and storing and has developed a guide called Hog Fuel Management, available on their website.32

Other solutions include very simple open storage buildings with a cement pad and an overhead roof. This will increase airflow, allow manual drying and keep the wood chips away from weather. Storage buildings or containers will also help keep contaminants out and keep the wood chips clean and to the desired specification. If storing in the winter, there is the possibility of freezing if moisture content is high. Freezing or binding of chips can cause significant problems when it comes time to transporting the chips off-site.

The amount of space storage space obviously depends on volume of chips produced and the rate they are sold to the market.

Transportation

Transportation can be a challenge in terms of logistics; having enough ground space for an adequate size transport vehicle to pick up and deliver the chips. Depending on the volume of the loads, this could range from a pickup truck to a larger transport truck (typically a B-train33) that is often used in the forest industry for delivering chips. Integrating a transport truck as large as a B-train is not insignificant.


There are a variety of wood shredders and chippers on the market. The Canadian Biomass Magazine produced a 2012 Chipper and Grinder Guide

34 that lists a variety of equipment. These equipment are all mobile, diesel operated systems.

Below are a few example products that are likely be suitable for small-scale forestry operators. It is noted that not many of the products listed specifically mention chips standardization (G30/50 or CEN/TC 355) but the manufacturers do promote the use of their chippers for bioenergy applications.

Bandit 3680XP Horizontal Grinder (http://www.banditchippers.com)

Bandit Industries offer a variety of chippers for many different applications. They offer disc and drum style, hand-held chippers that come in both diesel and electric versions.

32 https://fpinnovations.ca/Extranet/Pages/AssetDetails.aspx?item=/Extranet/Assets/ResearchReportsFO/ADV13N3.pdf#.U-ph02PpWnI 33 B-trains are typically two trailers connected together. They can typically haul 20 tonnes of wood chips and often have live floors to minimize unload time. 34 http://www.canadianbiomassmagazine.ca/images/stories/2011/November%20December%202011/2012_chipper_grinder_guide.pdf


The 3680XP Horizontal Grinder is specifically tailored for bioenergy applications (ideal for pellet plants, paper plants or wood boilers). It can produce chips from logging slash and sawmill waste. The XP version is equipped with a 60-tooth cutter mill with options for splitting, cutting, grinding or chipping.

Figure 9. Bandit 3680XP shredder35

Kesla 645 Chipper (http://www.kesla.fi/en/woodchippers)

Kelsa has two main wood chippers that are geared towards the bioenergy industry. The Kesla 645 chipper is the smaller model and comes in both a trailer and truck mounted option. There are a variety of 645 submodels offering different throughputs and feedstock intakes.

Weima Chipper WL500 or WL8 (http://www.weima.com)

Weima originated in Germany but now has presence in North America. The company focuses on shredding and briquetting. Their WL500 is a single shaft shredder popular for wood processing companies that generate waste. It produces wood chips (with changeable screen output between 10mm and 30mm) at a rate of 2 m3/hr.

The WL8 is their classic model for shredding all kinds of wood waste. The WL4, WL6 and WL8 series have been used by many small and medium businesses that generate wood waste. The WL8 has the lowest power requirement at 22 kW which might be high for small-scale forest operations in the Kootenays.

Weima products are represented and distributed by Ackhurst-Grainger in Delta, B.C.

Heizohack HM mobile chipper (http://www.eng.heizomat.de)

Heizohack wood chippers are drum chippers and are ideal for forest operators to produce wood chips for bioheat applications. The HM mobile chipper is ideal for small diameter wood and

35 http://www.banditchippers.com


waste wood but can also handle roundwood up to 40cm in diameter, producing chips between 35 and 40mm. Heizohack is a German company and no Canadian distributors could be found at time of writing.

Figure 10. Heizohack HM chipper36

Bruks Mobile Chipper 605 (www.mobilechipper.com)

The Bruks 605 mobile chipper is a small portable drum chipper with knives, suitable for the production of energy chips. It can handle logging slash (branches and tops of trees), parts of trees and small to medium size roundwood (40 cm maximum). The chipper can produce chips between 15 and 40 mm.

Figure 11. Bruks 605 chipper37

36 http://www.eng.heizomat.de/holzhackmaschinen.php?id=baureihe_hand 37 http://www.mobilechipper.com/index.php/products-by-name/mobile-chipper-605


3.3 Densification – wood pellets


Wood pellets are typically made from sawdust and small particle waste wood, compressed under high pressures and extruded through a die. Larger wood pelletizing technologies can start with wood chips as the feedstock. Uniform size and low moisture content makes wood pellets a very attractive fuel. Wood pelletization increases the energy content of the solid biofuel, thus reducing transportation costs when the product is sold to markets. Pellet manufacturers typically produce wood pellets that have a defined moisture content, energy content and burn characteristics (% ash). A typical wood pellet has a wood moisture content of 5–10% and an energy density of 18 GJ/tonne. Wood pellets are usually 2–3 times denser than wood chips. Wood pellets diameters are typically between 6 and 8mm and lengths vary up to 30mm. Pellets larger than around 30 to 40mm are classified as briquettes and are discussed in Section 3.4.

Figure 12. Typical wood pellets

Most of the 42 wood pellet manufacturing facilities in Canada are large scale, producing between 100,000 to 200,000 tonnes per year. These facilities are typically co-located with sawmills to take advantage of the sawdust produced. Large turn-key pellet facilities usually consist of a chipper, a dryer, hammer mill and pelletizer. The closest pellet mill facility to the West Kootenays is Lignetics Inc. located 230 km away in Sandpoint, Idaho. This facility has in the past purchased sawdust and wood shavings from large sawmills in the Kootenay area. Large-scale wood pellet manufacturing facilities have been commercial for several decades but the size and capacity obviously does not make them applicable to small-scale forest operators.

Medium-size systems (< 10,000 tonnes per year) are less common, but do exist. These facilities are also co-located with a sawmill, the added benefit being that the sawmill supports the administration and infrastructure cost of the pellet facility. Working with much lower volumes of wood fibre, these facilities can typically avoid the need for a dryer. As mentioned in Section 2.2, there are approximately 13 medium-scale pellet plants in B.C. summarized in Table 6. Even


though the facilities below are not large, they are still likely too large to be applicable to small-scale forest operations in the Kootenays38.

Table 6. Medium-scale pellet facilities

Facility Annual production (t)

Meadow Lake Tribal Council — Meadow Lake, Saskatchewan

6,000

Valley Lions Recycling — Swan River, Manitoba 2,000

Gildale Farms — St. Marys, Ontario 4,000

Industries Lacwood —, Hearst, Ontario 7,000

Marwood — Tracyville, New Brunswick 10,000

Exploit Pelletizing — Bishop’s Falls, Newfoundland 1,200

Bingwi Neyaashi Anishinaabek First Nation, (formerly Sand Point First Nation) — Beardmore, ON

6,000

Small mobile pelletizing technologies are available and would be more applicable to the volumes of waste wood generated by small-scale forest operators in the Kootenays. These systems were originally developed to produce pellets from a variety of feedstocks (grass pellets, straw pellets), but recent attention and popularity of wood pellets have brought small mobile pelletizers onto the market. They range in complexity from very simple machines that take sawdust to produce pellets to larger systems that have hammer mills and vibrating screens. These small-scale pellet machines produce pellets typically in the range of 50–300 kg/hr.


Wood pellets are most commonly manufactured from sawdust and shavings, which are typically white wood (resulting in higher quality pellets that have low ash content). Sawdust and shavings can be used directly in these smaller types of mobile pellet mills. The moisture content of the sawdust needs to be around 12–15% which is lower than the moisture content of typical sawdust, hence some sort of passive drying would be needed. Small-scale pelletizers need dry material, making upfront drying / storing a critical component of making on-site wood pellets.

Wood chips could be utilized but the pelletizer would need some sort of hammer mill to reduce the size of the feedstock. Larger classifications of waste wood including slabs, offcuts and hog fuel in general would need to be chipped first using chippers (as discussed in Section 3.2) or put through a larger shredder, grinder or hammer mill (not discussed in this report).

Using hog fuel or slabs with bark to make pellets will result in lower-quality pellets with higher bark (ash) content. Higher-quality pellets (predominately white wood) are typically used by the residential sector (in pellet stoves), while both higher and lower quality pellets are used by industry. One option could be to integrate a debarker into the operation to reduce the amount of bark included in the waste, as discussed in Section 3.1.

38 Although they might be applicable to medium-scale sawmills in the area


Pelletizing softwoods can achieve higher manufacturing productivity than pelletizing from hardwoods as softwood have slightly higher heating values.

3.3.3 Products and applications for small-scale forest operations

The production of wood pellets is likely viable for small-scale forest operators that have significant unwanted sawdust or wood shavings. Operations with hog fuel or slabs would require pre-processing (chipping), possibly making the process more challenging and expensive.

The market for low volume wood pellets is likely limited to local use — either for residential home heating using pellet stoves (see Section 4.1), or smaller commercial direct thermal combustion systems using pellet boilers (also see Section 4.1) that could use wood pellets as the main feedstock. Residential wood pellet stoves are a popular choice for certain locations in Canada (e.g. Nova Scotia, NWT). Pellet stoves are also ideal for rural residential applications or homes that use expensive electric heat. The stoves have a hopper that can be filled to allow the pellet stoves to run automatically for days. Residential Wood Pellet Heating: A Practical Guide

for Homeowners by the Arctic Energy Alliance39 provides good information on residential and commercial wood pellet heating systems.


Maintenance

The dies used to shape the pellets frequently wear out and require maintenance. Die wear-and-tear is higher when make pellets from hardwood species and also high when there is significant bark.

Pre-processing

Some small mobile pelletizers take only sawdust as the machines have no pre-processing capabilities. If the waste generated from the small-scale forest operators is hog fuel, slabs or offcuts, the waste would need to be pre-processed either separately or in a larger pelletizer that includes this functionality.

Bagging and storage

The production of wood pellets will require bagging and on-site covered storage until enough is produced to sell. The storage must ensure the pellets remain dry and free of contaminants. Residential pellets are usually bagged in 12–25 kg bags; these are often stacked onto one-tonne pallets. If a local commercial market can be found for the wood pallets where larger delivery by trucks is possible, a pellet silo could be a consideration. Silo design varies from large multi-tonne metal containers to smaller silos made of fabric as shown in Figure 13. Adequate fire protection must be in place when large volumes of pellets are going to be stored on-site.

39 http://aea.nt.ca/files/download/0773b7dc70d3a42


Figure 13. Small-scale wood pellet silo

Transportation

Depending on the quantity stored and pick-up load, transportation could be done by simple truck (for smaller loads) to flat-bed trailers for larger loads. The vehicles must be able to drive in and manoeuver on site.

Dust

Dust and fines can be a problem for both health and fire safety. If pellet production occurs indoors, proper ventilation and filtering are required to minimize dust, and fire protection equipment will be needed. This will be less of an issue if pellet production occurs outside.


There are a variety of different wood pellet technologies on the market. The Canadian Biomass Magazine produced a 2014 Pellet Gear Buyer Guide

40 that lists all the different types of equipment needed for medium- to small-scale pellet mills (dryers, mills, conveyers, bagging). The guide is intended for larger-scale systems but there is still useful relevant information for smaller operations.

There are quite a few mobile pellet mills on the market; most were originally designed for making animal feed but now claim to have been optimized for wood pellets. Many Chinese companies were found promoting their wood pellets systems41 but these are not reviewed in this report. Caution is recommended if exploring small-scale pellet mills. The few examples below

40 http://www.canadianbiomassmagazine.ca/images/stories/2014/julyaug14/pelletguide2014.pdf 41 GEMCO is an example of a Chinese company with significant web presence and multiple product offerings but no review of their products were found - http://www.gemco-machine.com/Pellet-Fuel/


are what are considered plausible and realistic products specifically designed for wood pellet production using waste wood. They are organized from smaller to larger pellet plants.

The Mini Pellet Mill (http://www.pelheat.com)

The Mini Pellet Mill is made by PelHeat in Great Britain and is a very compact pellet mill weighing only 100 kg. Originally designed to make feed pellets for animals, its design has been modified to accept woody biomass. It is capable of producing 20 kg/hour of wood pellets using sawdust and is manually operated. It has no pre-processing capabilities and has a small hopper to store the sawdust. The mill offers a single phase motor so it can be used in a non-industrial setting.

Figure 14. The Mini Pellet Mill42

Altocraft PMF-series electric pellet mill (http://www.pelletmillshop.com)

Altocraft USA Inc produces a variety of small-scale screw pellet mills. The PMF series are electrically-driven pellet mills with a varying throughput of 40-60 kg/hour (PMF6E6) up to 300-600 kg/hour (PMF12EC30). The smaller systems use a roller/die system for compressing the pellets while the larger systems have flat plates or two or three pairs of rollers. They produce pellets 6 to 8 mm in diameter.

42 http://www.pelheat.com/The_Mini_Pellet_Mill_Pictures.html


Figure 15. PMF6E6 wood pelletizer43

The Small-Scale Pellet Plant (http://www.pelheat.com)

This system is also made by PelHeat but is a larger version, offering a throughput from 100 kg/hr up to 3,200 kg/hr. It can be manually operated but also can be automatically configured. The system has a large feedstock bin, conveyor, variable speed augers, gravity hammer mill, 5mm screen, pellet press and die (6mm or 8mm dies) and final cooling conveyor.

3.4 Densification – briquettes


Briquetting is the process of compressing dried biomass with high pressure into solid bricks (rectangular or circular) or pucks, depending on the length they are cut at. These bricks can then be used as a direct thermal fuel or as a replacement fuel for industrial fossil fuel systems (with significant capital upgrades). Briquettes are similar to wood pellets but are generally larger and used for different applications. Briquetting technologies are much more accepting of the type and quality of feedstocks utilized — offering a significant advantage over the production of wood pellets. Similar to wood pellets, the lignin in the wood acts as a binding agent when the biomass is under pressure.

Briquetting technologies are commercially available and scalable; systems can generally be smaller than wood pellet systems based on the economics. The systems can be adjusted to produce different types of briquettes — long versus short and rectangular versus circular — depending on the press type. Typical diameters of briquettes range from 5 cm to 10 cm and lengths vary between 6 cm to 15 cm, but smaller pucks are becoming more common. Most

43 http://www.pelletmillshop.com/Small-Wood-Pelletizer-Machine-Online.html


briquetters offer variable cutting so they can produce short pucks for industrial use or long pucks for residential fire use. Example briquettes are shown in Figure 16.

Figure 16. Typical sawdust briquettes44

Most briquetting systems required dried biomass (< 10% moisture content) but some do come with their own drying capability. The capital costs of the system depend on how dry the biomass is and whether pre-processing is required.

There are two main different types of small-scale briquetting systems.

• Hydraulic press – Complete systems with production capacity of 50–200 kg/hr, producing (usually round) briquettes using hydraulic pressure. Hydraulic presses are effective at compacting sawdust.

• Mechanical screw press – Screw press briquette systems can produce briquettes with high energy density, but usually require higher energy consumption compared to hydraulic press systems.

Briquetting system configuration can include in-house type briquetters, containerized systems or a fully integrated silo system (different examples shown in Figure 17) where waste wood is collected and stored in the upper section and briquetting happens in the lower section.

Both diesel- and electrically-powered briquetting systems are available.

Figure 17. Briquetting system configurations

44 Picture from http://www.cfnielsen.com/infoen/-10



Most briquetting systems work with sawdust that already has low moisture content (< 15%). Some systems take larger particles (i.e. wood shavings) of no more than ¾” x ¾” by 1/8”.


Developing a briquetting system in conjunction with existing small-scale forest operations is a viable option if a local market for the briquettes can be secured. Because of their size, briquettes can’t be substituted for pellets in pellet stoves or boilers. Briquettes can replace wood for residential home heating in fireplaces as well as for industrial boilers. Possible commercial applications include pizza ovens, meat / fish smokers or large BBQs and greenhouses, which could use the briquettes as a replacement for firewood.

A briquette system could potentially be used on-site for process heat in drying kilns.


Considerations (pre-processing, bagging, transportation) for on-site briquetting are similar to pellet production.


Holzmag ElanB60 Briquetter (http://www.briquettingsystems.com)

Holzmag briquetters are manufactured in Switzerland and have been sold for over 30 years. These screw-type briquetters have a throughput of 200 kg/hr and have been deployed in small and medium woodworking plants. This type of briquetter produces a briquette 60 mm in diameter and between 50 and 100 mm in length. The maximum biomass moisture content these systems can take is 15%.


Figure 18. Holzmag Elan B6045

Holzmag briquetters are distributed through Briquetting Systems Inc. based on Vancouver, B.C. Briquetting Systems have 15 operational briquetting systems in North America.

C.F. Nielson BP 2000 (http://www.cfnielson.com)

The BP 2000 is C.F. Nielson’s smallest briquetting system, suitable for small-scale forest operators that have less than 1,000 tonnes of waste wood per year. It is capable of handling sawdust, shavings and even wood chips. It is an automatic system that has a large hopper for feedstock storage and a capacity of 150–225 kg/hr, producing a briquette 50 mm in diameter.

C.F. Nielson is Denmark’s leading manufacturer of briquetting systems, offering both stationary and mobile briquetters. Their mobile briquetters are housed within 20-foot containers and include a mechanical briquetting press, silo with feed system, dosing screw, cooling lines and controls.46

45 http://www.briquettingsystems.com/brochures/BricketterBroc.pdf 46 http://www.briquettingsystems.com/brochures/briquetter-mobile-plants.pdf


WEIMA C150 Briquette Press (http://weima.com)

Weima, based in South Carolina, produces several small-scale briquetters. The C150 briquette press is their smallest system offering throughputs of 50-80 kg/hr. The system utilizes sawdust, and a Weima shredder can be added if pre-processing is required.

Figure 19. Weima C150 briquetter47

47 http://weima.com/usa/machinery/briquette-presses/c-series/c150.html


4. Thermal and thermal-chemical conversion

This section provides information on the third and fourth classification of bioenergy technologies – thermal conversion and thermal-chemical conversions. Both technologies involve the combustion of the biomass with varying levels of oxygen, as shown in Figure 20.

Figure 20. Thermal chemical conversions with varying levels of oxygen

Thermal-chemical conversion technologies, first and foremost pyrolysis, are in a rapid state of development in Canada and internationally (most noticeably in the U.S. and EU). Numerous companies offer fast and slow pyrolysis systems with varying focus between bio-oil and biochar, as well as torrefaction. A report by Sixth Element Sustainability Management48 states that almost 500 companies worldwide offer gasification or pyrolysis solutions, with Canadian companies representing 16% of these — a high per capita level. The article reinforces the lack of credibility of some of these companies; many have a web presence but not much more. The information collected and presented in Sections 4.2 - 4.4 attempts to filter out these startup / marketing companies but it is acknowledged it is challenging to do so without directly interviewing or discussing the company’s deployed technologies. The three main thermal and thermal-chemical conversion technologies, along with a brief description and potential applications / products, are listed in Table 7.

48 Referenced in an article from the Canadian Biomass Magazine (http://www.canadianbiomassmagazine.ca/content/view/4563/57/)


Table 7. Thermal and thermal-chemical combustion technologies

Technology Description Application / Product

Direct thermal combustion The thermal combustion of biomass in an air-rich environment

space or process heat

district heating

water heating

electricity

Gasification The thermal combustion of biomass in an air-restricted, high temperature environment to create syngas. This syngas is then combusted in an internal combustion engine to produce electricity.

electricity through the production and combustion of syngas

Pyrolysis The thermal combustion of biomass in the absence of oxygen, also at high temperatures. Slow pyrolysis and fast pyrolysis technologies are explored to produce varying types of byproducts

biochar

bio-oils

syngas and electricity generation49

Since different biomass feedstocks have different characteristics and chemical breakdowns, thermal-chemical combustion systems are designed with specific feedstocks and feedstock characteristics in mind; this ensures the best combustion and optimal performance is achieved and serious problems including fouling, corrosion and residue buildups are avoided.

4.1 Direct thermal combustion – heat


Direct thermal combustion of wood biomass for heat is the most basic technology and has been used for centuries. In its simplest term, biomass is burned in an air-rich environment with heat being its main usable byproduct. This heat can then be used for space heating, process heating, water heating for direct use or in a district energy system where the heat is transferred to other end users as hot water through a series of underground pipes.

Direct thermal combustion technologies for heat have the most direct applications, with mature technology and an established track record of commercial-scale operations in many countries.

The main technologies for direct thermal combustion applicable for small-scale systems are summarized below. More information is in Table 8.

• hog fuel boilers – biomass systems specialized to use hog fuel. Large-scale sawmills have adopted hog fuel boilers to deal with their waste wood problems. Hog boilers (also referred to as power boilers) are usually larger capacity systems designed to heat water for a variety of purposes (steam generation with Rankin cycle or hot water usage)

• cordwood stoves/boilers – biomass systems focusing on cordwood or briquettes. These are typically smaller systems that are used for residential space heating applications (cordwood stoves) and small- to medium-size commercial. They focus on burning logs

49 Even though pyrolysis can be used for electricity generation, it is not a focus of this research


for direct space heating or hot water heating for a variety of purposes (hydronic heating, hot water usage).

• wood chip boilers – biomass systems utilizing uniform wood chips. These systems range in capacity. Wood boilers are used in larger commercial applications.

• wood pellet stove/boilers – biomass systems utilizing wood pellets. Pellet stoves are often used for residential applications and larger wood boilers are used in commercial or industrial applications.

These systems vary in complexity with regards to feedstock storage, handling, combustion chamber and design, air emission controls and ash management. All thermal combustion technologies are well commercialized and available in a variety of capacities.

Figure 21. Different thermal combustion technologies50

50 Adapted from Wood Waste to Energy Technology: The Good, the Bad, and the Ugly. Canadian Biomass to Energy Research (CBER), with permission


Table 8. Types of heat-only thermal combustion systems applicable for small-scale systems

Technology Feedstock Description Estimated efficiency

Capacity

Hog boilers Hog fuel (possibly mixed with sawdust)

Large systems focused on combusting large volumes of low quality biomass feedstock for the purpose of heating water. Can be used for power generation (for large systems).

60–80% 1–100MW

Cordwood / log boiler

Cordwood, unmerchantable logs, slabs, briquettes

Log boilers are basic simple fireboxes that combust batch cordwood. Most are manual and do not have any automatic controls.

Most likely used for space heating or possibly process heat (kilns).

Cordwood boilers are available in outdoor units as well as indoor units

70–95% Up to around 100 kW

Pellet stoves Wood pellets Similar to cordwood boilers, but use wood pellets as the feedstock. Still used for mostly space heating or possibly process heat (kilns). Slightly more automated as pellet stoves come with an integrated hopper that stores the pellets.

70–90% 2–12 kW for residential use

20–50 kW for heating larger buildings

Pellet boiler Wood pellets Pellet boilers are larger equivalents to pellet stoves, but heat water and use water as the mechanism to transfer heat.

Starting at 15 kW

Pile burners (fixed grate) – historical industry method and first main type of boilers. They have a fixed grate and typically consist of a two-stage combustion chamber. They are best used for a combined feedstock of chips and sawdust, but not a mixture of more than 30% sawdust.

50–60% 100 kW – 1 MW

Stoker grate boilers – an improvement to pile burners by the addition of a moving grate which permits continuous ash collection (and removes the need to shut down and start up the system).

Fluidized bed boilers – larger capacity systems that are not applicable for the scale of systems considered in this research

60–80% 100 kW – 2 MW

Chip boiler Wood chips Largest type of system and most appropriate for medium and large-scale heating applications.

Start around 25 kW (but 40 kW most common), up to mid-500 kW


A typical direct thermal combustion system can be comprised of one or more of the following components, depending on the type and complexity of the system:

• feedstock storage – storage of the biomass feedstock before it is introduced to the combustion system. Storage can be a storage bin or container for cordwood, storage bin or hopper for wood chips, or a silo for wood pellets.

• feedstock handling system – components that handle the transfer of feedstock into the main combustion component. This can be manual (e.g. for cordwood boilers) or fully automated (for wood chip systems). Wood chips handling systems are the most sophisticated type with screw augers to transfer the stored biomass to the combustion system and moving grates inside the combustion chamber.

• biomass furnace or boiler – the main combustion chamber for the feedstock.

• controls – automate the rate of the biomass feedback introduced into the combustion chamber and the level of oxygen present during combustion. Other controls might deal with possible moisture content variability in the feedstock.

• chimney / flue gas treatment – a chimney where the combustion gases are removed from the system and sent to the atmosphere.

• air emission equipment – equipment such as electrostatic precipitators, cyclones or baghouses that scrub particulate contaminants from the flue gases.

• ash handling – storage and removal of ash produced during combustion. This can be manual or automatic.

NRCan produced a report in 2000 entitled Buyer’s Guide to Small Commercial Biomass

Combustion Systems.51 Although a little outdated, it provides some valuable information on

small-scale biomass combustion systems, feedstock characteristics, operations and costing.


The information below is summarized by thermal combustion technology, as different technologies require different feedstocks. The most likely feedstocks to be used in direct thermal combustion systems are hog fuels, sawdust/savings, cordwood or wood chips produced on-site. Wood pellets produced on-site are not usually directly combusted, as selling them usually makes more economic sense.

The acceptable moisture content of feedstocks for direct combustion systems is typically around 30–40% (in some cases e.g. for hog fuel, moisture content around 60% is upper limit52), although lower moisture improves combustion efficiency. This requirement for lower moisture content means that there should be some level of manual drying or covering of any waste feedstock that is produced on-site, as these have typical moisture contents of 40–50%. Beyond this percentage, there is little calorific heat value in the fuel as most of the energy in the biomass is spent boiling

51 http://publications.gc.ca/collections/Collection/M92-186-2000E.pdf 52 Biomass Availability Study for District Heating Systems, EnviroChem Services, Inc, 2012


off the water. Efficiency also drops, leading to high emissions of carbon monoxide (from incomplete combustion) and unburned hydrocarbons.

The consistency of the feedstock is also extremely important, specifically for wood chips systems. Some systems state whether they require chips in accordance with the G-size classification.53 Most systems can handle seasonal swings of varying feedstock quality (by adjusting system controls), but not hourly variation.

Cordwood boilers

Cordwood boilers require very little pre-processing of the biomass feedstock. Cordwood boilers could be a suitable application if the small-scale forest operations have unmerchantable logs / timber or large slabs and it is not practical or feasible to process these into wood chips. The only processing required would be to cut the feedstock into the required length and store the material under some form of cover to reduce the moisture content. Typical cordwood boilers work best if the fuel has less than 30% moisture content. Some amount of sawdust can usually be mixed in with cordwood boilers; its high surface volume improves the burn characteristics.

Pellet stoves and boilers

Pellet stoves are typically used for space heating. They typically range from 5–12 kW and are around 90% efficient. When using high-grade pellets that have low bark content, less than 1% of the pellet results in ash. Pellets would have to be sourced and stored indoors to prevent them from getting wet.

Pellet boilers are used for larger heating applications and rely on more automation and control than simple pellet stoves. Pellets are stored in hoppers where they are fed into the combustion chamber through an auger. Pellets would also have to be sourced and stored indoors before being introduced into the hopper.


Space heat or water heating

Space heating or water heating are great applications for on-site direct thermal combustion systems. Most small-scale forest operations will have buildings that will need heating or hot water (although the latter is likely minimal). Having waste wood on-site and an energy source to satisfy this demand using well-proven technology is an ideal situation. Hog boilers or cordwood boilers utilizing unmerchantable, defective wood or slabs is the simplest choice, followed by a wood chip boiler if on-site wood chipping is feasible. The feasibility of replacing conventional heating systems (natural gas, electric heating, oil boilers, propane heating systems) will depend on capital upgrades of the heating system and the cost of the conventional fuel. In the Kootenays, natural gas is a relatively affordable heating fuel, whereas electric heat (baseboard heaters), oil and propane are relatively more expensive.

53 http://www.biomassenergycentre.org.uk/portal/page?_pageid=77,317197&_dad=portal&_schema=PORTAL


Spearhead Timberworks Inc., a value-add wood manufacturing company on the west arm of Kootenay Lake, has an outdoor wood boiler that is used to space heat their large workshop. The boiler is a Central Boiler Model CL 6048 that utilizes offcuts after wood has been kiln dried, as well as waste solid wood.

Process heat

An excellent synergy with local sawmills is the use of thermal heat for kiln drying. There are some complexities with matching the heat demand of the kilns with the startup and shutdown of the kilns, but this represents an application worth exploring.

Another option is to integrate a greenhouse into your operations that is heated using waste biomass. A report in 2006 by REAP Canada for NRCan54 looked at various options for using bioheat in the Canadian greenhouse industry.

District heating

District heating systems are more applicable to urban applications, but could be a consideration to rural sawmill operations if the right conditions exist. Most small-scale operators have more waste wood than they need for any sort of heating application, so investigating heat demand within proximity to the operations might be of value. With rural district heating applications, there are fewer infrastructure barriers and restrictions. A 2012 report prepared for the BC Bioenergy Network and Biomass Availability Group entitled Biomass Availability Study for

District Heating Systems55 provides some excellent information for anyone interested in

exploring this option. A more recent report published in 2014 by the Community Energy Association called Small-scale biomass district heating handbook: Reference book for Alberta

and B.C. Local Governments56is an excellent resource for small communities in Alberta and B.C.

that are interested in exploring district energy opportunities.


Feedstock storage

Similar to feedstock for wood chips and pellets, storage will become very important. A dedicated storage building will likely be needed to keep the biomass dry — a simple storage shed, framed bin (A-frame or rectangular) or below-ground bunker. It will require ventilation and good airflow. Depending on the storage type, proximity to the boiler and boiler size, a front end loader or forklift might be needed to move the feedstock from storage to the system.

54 http://www.reap-canada.com/online_library/feedstock_biomass/Biomass%20Resource%20Options%20Creating%20a%20BIOHEAT%20Supply%20...%20%28Bailey%20et%20al.,%202006%29.pdf 55 http://www.bcbioenergy.ca/wp-content/uploads/2012/02/Complete-Biomass-Availability-Study-Feb-7-2012-Final.pdf 56 http://www.toolkit.bc.ca/Resource/Small-Scale-Biomass-District-Heating-Handbook


Air quality regulations

Currently, in the B.C. Ministry of Environment (MoE) does not have any regulations around air emissions from biomass combustion facilities. Only high risk and medium risk industrial operations are required to have authorization before discharging emissions (air, land, water) or waste to the environment under the B.C. Environmental Management Act. For commercial biomass-fired boilers, the MoE has developed a Guideline57 that outlines limits for particulate emissions (PM2.5 and PM10), opacity of smoke and dioxins / furan emissions. For smaller-scale biomass systems, the level of responsibility to the level of air emissions from the facility will lie with the project implementer and local authorities who approve the project.

Building requirements and boiler regulations

Building code and other regulations will need to be consulted when designing a separate building that would contain the biomass thermal combustion system or when integrating a biomass boiler into an existing building. Safety standards outlined by the B.C. Safety Authority Act such as the Approval of Biomass Boilers in Accordance with the British Columbia Safety Standards Act will need to be adhered to.


There are many biomass boiler manufacturers and companies on the market, all offering different capacity, allowable feedstocks and application focus. Many are large-scale systems that focus on producing hot water for a variety of purposes. Some direct combustion systems use the terminology gasification to signify the various combustion stages the gases go through, but these systems are not true gasification systems (this is discussed in Section 4.3). The selected technologies below give a brief overview of some systems that would be applicable for small-scale forestry operations. For a full list of biomass boilers and related equipment, refer to the Biomass Boiler Buyers Guide published by Canadian Biomass magazine.58

Fröling S3 Turbo (http://www.evergreenbioheat.com)

The Fröling S3 Turbo is a cordwood boiler that can take up to a half-meter length of cordwood (could possibly be used for slabs as well). It is considered a residential / light-commercial boiler and is designed to be loaded once a day. It has an output range of 18 to 45 kW and is has a high temperature turbulence combustion chamber with high combustion values.

The S3 Turbo comes in four different configurations offering slightly different capacity outputs. The weight of the four configurations range from 520–610kg.

57 http://www2.gov.bc.ca/gov/DownloadAsset?assetId=EDD4D129095F4DE99D2969621C75658D 58 http://www.canadianbiomassmagazine.ca/images/stories/2011/mayjune11/biomassboilerbuyersguidelr.pdf


Figure 22. Froling S3 Turbo59

Bio-Burner BB series (http://www.leiprod.com/leiproducts/the-bio-burner/)

The Bio-Burner BB series boilers are used for a variety of applications. The BB-100 model (29 kW) is a chip-fed biomass boiler system that takes wood chips with moisture content up to 40%. It is intended for residential or light industrial, capable of heating up 6,000 ft2 of space. It has the ability to burn a variety of feedstocks including wood chips and wood pellets and other waste byproducts. The BB-500 series (150 kW) is for light commercial or industrial applications and can take a variety of feedstocks: chips, pellets and other waste materials.

The BB series uses propane or natural gas as a startup fuel and can run on these fuels if the fuel bin runs out of feedstock. Bins for the different models are optional and come in 2-yard, 11-yard or 22-yard sizes. The bins also come with motors, augers and computer controls. All models are EPA certified. These models can also be used for wood kilns.

Two suppliers in B.C., Ventek Energy Systems (Quesnel) and Advanced Wood Heating (Blind Bay), carry Bio-Burner products.

Viessmann-KOB Pyrot (https://www.viessmann.com)

Viessmann/KOB is one of the most reputable biomass boiler manufacturers on the market. Austrian-based, they provide many different boiler configuration for a variety of heating needs.

The Pyrot DYN boiler is their smaller biomass boiler60 and is a flexible fuel system capable of burning a variety of feedstocks with maximum 35% moisture content: sawdust, pellets, chips and a variety of mixed woods that meet the G50 size specification. The Pyrot DYN boiler is a

59 http://www.froeling.com/en/products/firewood/froling-s3-turbo.html 60 Viessmann-KOB’s larger biomass boiler is the Pyrotec DYN


moving grate burner offering 90% efficiency. There are five different Pyrot models ranging in capacity from 150 kW to 540 kW.

Fuel storage and feed systems can be specifically designed based on the utilized feedstocks.

Figure 23. KOB Pyrot biomass boiler61

Viessmann Canada’s head office is located in Waterloo, Ontario and they have a west coast sales centre in Langley, B.C. Fink Machines Inc., located in Enderby, B.C,. is one of the main distributors of KOB boilers in B.C., having installed over 40 boilers across Canada and the U.S.

Herz Firematic 90-150 kW boiler (http://www.herzvalves.com) )

Herz is the leading Austrian manufacturer in the global heating industry. The Herz Firematic boiler burns wood chips (max G30 size) and pellets. It has a self-cleaning burner option during combustion; automated cleaning also happens on the vertical pipe heat exchanger.

The Firematic 90 kW boiler has an output range of 27–90 kW and can provide hot water at a maximum temperature of 90ºC.

Herz boilers are distributed in Canada by Western Bioheat Corp. located in Langley, B.C.

4.2 Direct thermal combustion for power generation – Organic Rankin Cycle

This section discusses direct thermal combustion for the main purpose of power production, which is a very different application than using direct thermal combustion for heat production.

Some systems combine electricity production with utilization of excess heat that is not converted to electricity; this is called combined heat and power (CHP, also referred to as cogeneration). CHP systems have quite higher overall system efficiencies because of this heat utilization. The

61 http://www.viessmann.ca/content/dam/internet-ca/pdfs/wood/biomass_brochure.pdf


technical and economic feasibility of cogeneration depends on the availability of a market for heat that is close to the power generation facility. Capital costs also increase due to the cogeneration and heat transportation infrastructure, and most systems must reduce their electricity production to some extent to make cogeneration feasible.


One of the most common external combustion systems is the Organic Rankin Cycle (ORC) engine. ORC technologies are not specific to biomass and work on the concept of utilizing low-grade waste thermal heat from other systems (fossil fuel engines and motors, waste water). But they can indeed work with waste biomass – the biomass is combusted in a separate biomass boiler to heat water and this water then fed into the ORC system. When an ORC system is used in partnership with the combustion of waste wood, the electricity generated is considered green electricity. ORC systems have been around for a long time, dating back to the early 1900s, but the expansion of large-scale, centralized electricity generation killed many of these technologies.

Instead of water, ORC systems use an organic working fluid (freons, organic solvents, silicone oils) that has a lower boiling point than water so they can be used without a certified steam operator, making them ideal for smaller-scale systems or remote communities. The evaporated gas passes through a turbine attached to a generator to produce electricity. The gas then condenses back to the working fluid. Most ORC systems use turbines for electricity generation, but single- and double-screw systems are also possible. Screw systems work on lower temperatures and don’t require all the working fluid to expand into a gas, i.e. they can operate with a wet working system. The downturn of screw systems is that they have lower efficiencies. There are a few small-scale ORC systems on the market that range from approximately 50 kWe to 250 kWe. The more prevalent systems, however, are larger ORC systems in the MW62 range.

The efficiency depends on operating temperature and can range from a low 8% (for low temperature systems ~ 100ºC) up towards of 23% (for high temperature systems). The lower efficiencies are a result of low fluid pressure, and are a significant weak point in ORC systems. The efficiency of the system can however be increased if the waste heat can be utilized.


ORC systems do not specifically work on a biomass feedstock. Instead, they work on waste heat, typically in the form of hot water. Therefore, a full ORC biomass system would require a biomass boiler in conjunction with an ORC system. The feedstock requirements for the biomass boiler would be the same as the requirements in Section 4.1.2. A hog fuel boiler or chip boiler would be ideal for an ORC system as these boilers will have the lowest capital costs.

Input temperature ranges for ORC systems generally fall between 80ºC and 130ºC.

62 http://ctcg.org/wp-content/uploads/2011/07/Summary-Guide-to-Technologies-Considered.pdf



ORC systems could be used to provide base load electricity to sawmill operations. Connection to the electricity grid would be important so any excess electricity that is generated can be exported to the grid, or any additional electricity needed at the facility can be drawn from the grid. The electrical utility in the West Kootenays (Nelson Hydro or Fortis BC) would need to provide a net metering program to enable the electrical connection. At the time of writing, neither utility provided net metering for electricity generated from small-scale biomass systems.

Because of the low efficiency of ORC systems, only very small capacity systems (less than 50 kWe) would be viable because of the large amount of biomass that would be needed. For example a 50kWe system operating at 10% efficiency would require approximately 200 BDT tonnes of biomass.

If there is the demand, excess heat could be used on-site. Heat could be used to provide heat to kilns, or even space heating for buildings on the property.


Although they don’t operate using steam, ORC systems still operate under pressure and often require thermal oil boilers to bring the temperature of the water beyond 100ºC to avoid pressurization. It is difficult to install systems like this under some jurisdictional regulations. But under B.C. Regulation, ORC systems are classified as unfired pressure vehicles and should have fewer barriers to deployment.

There are some systems that have non-corrosive, organic working fluids, but the working fluid in other systems can be toxic and highly flammable, which could have negative environmental effects if a spill was to occur.

Although ORC systems have quite high capital costs compared to other bioenergy technologies, ORC systems can be fully automated and hence can have relatively low operation and maintenance costs. They have been known to have a long service life.

Electricity produced from these systems is often 3-phase and high voltage alternating current (~ 300 – 400 VAC), possibly limiting their appropriateness for very small sawmills and forestry operations.

Finally, similar to thermal combustion systems, air quality regulations and building regulations will need to be complied with.


The technologies listed below are not specific to biomass systems. They are independent, small-scale ORC systems that could be integrated with a biomass boiler. There are very few examples in Canada of using ORC systems with waste biomass. Most systems of this configuration are deployed in Europe. Italian Turboden (http://www.turboden.eu, part of UTC Corp) produces an ORC system that is very tailored towards biomass applications. Their HRS systems are larger systems (minimum 200 kW) that have been applied to timber drying in large sawmills, sawdust


drying for pellet production, pellet and MDF board production and greenhouses. Tri-O-Gen (http://www.triogen.nl/) is another company that focuses their ORC systems on biomass.

BEP ORC systems (http://www.e-rational.net/)

This Belgium company produces single-screw ORC systems with capacity of 50 –250 kWe (at a power voltage of 400 VAC). Electrical efficiency is in the range of 10%. Their ORC technology operates on waste heat in the temperature range of 80–150ºC. The system is based on a screw expander connected to an asynchronous generator and hence avoids expensive components and transmissions systems. The working fluid of E-Rational ORC systems is environmentally safe, inflammable and non-toxic.

BEP originated in Europe but is currently based in Grand Rapids, Michigan.

Figure 24. E-Rational ORC system63

ElectraTherm Green Machine 4200 (http://electratherm.com)

ElectraTherm, based out of Reno, Nevada, has several small-scale ORC systems. Their Green Machine 4200 is their lowest capacity system, offering 35 kWe (380–500 VAC), and works with hot water in the temperature range of 77–116ºC. It is a screw-based system working with an axial turbine. Its working fluid is R245fa, a non-flammable, non-toxic and non-ozone depleting fluid.

Enef Teck EnefCogen Green 10kW (http://www.eneftech.com)

Enef Teck, based in Switzerland, develops mini-ORC systems and works with waste heat in the temperature range of 120–200ºC. Their 10 kW system can operate in a 5 kW mode and requires between 125–135ºC. It is a cogen system offering 95% efficiency (5kWe and 45kWth for their 5kW mode).

63 http://www.e-rational.net/sites/default/files/attachments/E-RATIONAL%202013-ENG.pdf


It is unknown whether there are any distributors of Enef Teck products in Canada.

General Electric Clean Cycle 125 kW (https://www.ge-distributedpower.com)

GE’s Clean Cycle from GE’s Heat Recovery Solutions division is a gearless, integrated power module with high-speed turbine (single-stage radial) expander and alternator in one complete unit. Its power electronics turn high-frequency output into utility-grade power. It provides 125 kW gross output power utilizing 980 kW of waste heat at a temperature of 121ºC. It also uses R245fa as the refrigerant.

Figure 25. GE Energy Clean cycle ORC system64

GE Energy in Canada is represented by GE Power and Water in Calgary, Alberta.

Turboden 2 200 kW (http://www.turboden.eu)

Italian Turboden’s history and projects is rooted in cogeneration from woody biomass. Their biomass cogen systems are on the higher capacity side (200 kW – 15 MW). The Turboden 2 200 product requires 558 kg / hour product and offers 16% efficiency. Turboden has 300 systems installed worldwide with two in Canada.

4.3 Gasification for power generation

4.3.1 Technology description and technology maturity

Biomass gasification for power generation involves heating biomass at temperatures around 800°C in an air-restricted environment which prohibits complete combustion (partial oxidation of organic material), resulting in a synthetic gas that can be then used as a combustible gas in an internal combustion (IC) engine.65 Both gas- and diesel-powered ICs can be used in biomass-

64 https://www.ge-distributedpower.com/products/heat-recovery-solutions/clean-cycle-125 65 Kralovic, Paul and Mutysheva, Dinara. The Role of Renewable Energy in Alberta’s Energy Future, (ISEEE, 2006), 17, http://www.iseee.ca/files/iseee/ABEnergyFutures-15.pdf, (accessed July 15, 2009).


based gasification systems. The vast majority of IC engine producers do not target the biomass-syngas industry directly, but there are a few IC engines (GE, Jenbacher) that have been used by gasification companies and integrated with their gasifiers.

The resulting combustible syngas from the gasification process has energy potential, but typically has a much lower heating value than natural gas (10–20% of the energetic value of natural gas).66 This low energy content is one of the major challenges of gasification-IC systems. Gasifiers can operate using both air and pure oxygen as the catalyst. Using pure oxygen instead of air can increase the energetic value of the syngas to about 50% of natural gas67 but this comes at a substantial capital costs and is not realistic for the scale of systems discussed in this report.

The majority of gasification systems are large-scale systems (> 5 MWe) and are considered near-commercial. The most common types are fluidized-bed and entrained flow systems. Only fixed-bed gasifiers exist at small scales. There are two types of fixed-bed gasifiers that are based on the direction of flow of the syngas:

• Downdraft gasifiers (co-current gasifiers) – 80–350 kW

• Updraft gasifiers (counter-current gasifiers) – 500 kW – 4 MW

Syngas-IC usually has a higher electrical efficiency than other biomass-to-electricity technologies (e.g. ORC) at around 25%. This higher electrical efficiency of gasifiers and ICs is one of their biggest benefits.

Most of the current available small-scale gasification-IC systems are from Europe (Denmark, U.K. with some in the U.S.). Generally speaking, the gasification-IC market straddles the early commercial / commercial stage. The majority of deployed small-scale gasifiers are fixed-bed, downdraft air-blown units – they are quite simple in design and hence have a relatively low capital cost (but produce low energy content syngas). There are quite a few on the market but have not yet reached full commercial status because of the substantial tar that is generated in the gasification process (especially by systems over 100 kW). Large-scale systems are even more challenging and have had less success over the years as they still require significant engineering and research technical and financial support.

ORC versus gasification for power - Both ORC and gasification for power are technologies that generate power from waste wood. Table 9 provides a summary of some of the advantages / disadvantages of ORC and gasification

Table 9. Advantages / disadvantages for ORC versus gasification

Advantages Disadvantages

ORC (direct thermal combustion)

Operates at a lower temperature

Can be fully automated

Simpler systems and cost

High system up-time

Low electrical efficiency ( 10% - 18% max)

Risk of flammable and toxicity with the working fluid

66 BIOCAP Canada, Pursuing Biomass Energy Opportunities and Technologies in British Columbia, 25. . 67 Air-blown gasification syngas – 4-6 MJ / m3 of syngas, compared to oxygen-blown gasification syngas of 10-20 MJ / m3.


Can take lower quality feedstock

Gasification Higher electrical efficiency (up to 25%)

Lower emissions than direct thermal combustion

More uses for syngas and can filter syngas

Possible high levels of carbon monoxide in the syngas

Need high quality and consistent feedstock

Use of IC for power generation higher capital costs and additional maintenance required


High quality feedstock is much more important for gasification-IC systems compared to external combustion systems. To avoid tar and severe maintenance issues resulting from tar buildup, dry white woodchips are required, especially for downdraft gasifiers. Moisture content should be less than 15% and the feedstock should contain little bark or impurities. Systems can take feedstock with higher moisture and bark content but greater tar production will result. Tar infiltrating the IC engine and decreasing / killing electricity generation performance is the main challenge.

Sawdust does not work well with gasifiers as they need less fine material; wood chips or shavings are ideal. Hog fuel will not work as its high bark and moisture content leads to tar problems.


Gasification-IC systems should be considered if on-site electricity generation is needed and there is a use for the waste heat, but this is undoubtedly not the right choice for small-scale forest operations at this point in time. There are other electricity producing technologies (eg. ORC) that are more cost effective and commercialized than gasification-to-power systems. Positive project economics will be very difficult to achieve if the cost of electricity used at your operations is already affordable. Offsetting electricity from diesel generation might be a consideration to explore.


Even very small gasifiers offering electricity output below 100 kW require a significant volume of biomass because of the low efficiencies of the systems. Because of this inefficiency, gasification may be more applicable for medium-sized sawmill operations that have higher volumes of waste wood.

It must also be ensured that the electricity produced from the process is at an appropriate frequency and voltage based on the on-site electricity needs at the mill. In terms of connecting to the local utility grid, the same applies as for ORC systems; the electrical utility in the West Kootenays (Nelson Hydro or Fortis BC) would need to provide a net metering program to enable the electrical connection. At the time of writing, neither utility provided a net metering for electricity generated from small-scale biomass systems.

As discussed above, the quality of the feedstock is key. If the available waste wood is already clean (shavings) and free of bark, gasification might be worthwhile to consider when


technologies further mature. But if any sort of pre-processing is required (i.e. debarking), ORC systems would be a better alternative.

The effects of high tar content is the other significant challenge. Tar compounds condense and stick to internal components of the IC. There are many technologies that clean the syngas, but these range in complexity and level of success.


As noted, small-scale gasification-to-power systems are available on the market, but they are still in the hazy area between near commercialization and full commercialization. The two examples listed below appear to be fairly commercial. From the review of the companies offering small-scale gasification systems, there are only a small handful based out of Europe. The technologies listed focus on the gasifier and do not cover IC engines.

Spanner Re2 (http://www.holz-kraft.de/en/)

Spanner Re2 was founded in 2004 as part of Otto-Spanner in Germany. They are present in seven countries worldwide (including Canada). The Spanner Re2 is a wood cogeneration plant, with hundreds of these systems used in Europe, Asia and North America in the agriculture and forestry industry.

There are two main cogeneration plant designs offering 30 and 45 kW of electricity and 80 to 120 kW of heat. Wood consumption is about 30 and 45 kg/hr. The systems use conventional clean wood chips and consist of an innovative reformer and a CHP power by wood gas.

Figure 26. Spanner Re2 gasifier and CHP system

68

The Spanner Re2 is distributed in Canada by Borealis Wood Power based out of Burlington, Ontario.

Community Power Corp BioMax (http://www.gocpc.com)

68 http://www.holz-kraft.de/en/products/wood-cogeneration-plant


Community Power Corp offers the BioMax 100 kW gasifier. It is a modular, fully automatic fixed bed gasifier that converts waste biomass to a syngas high in hydrogen and carbon monoxide. The syngas can be used to generate electricity or be used for heating or cooling. The BioMax 100 module comes in a standard 20’ ISO container block and can be connected together to provide more power.

The required waste biomass is on the higher end, requiring over 3 BDT / day of feedstock.

4.4 Pyrolysis

4.4.1 Technology description and technical maturity

Pyrolysis is a thermo-chemical process where solid biomass is heated at medium temperatures (400–600ºC) in the absence of oxygen and undergoes thermal decomposition to produce syngas, bio-oils (mix of hydrocarbons and tars) and biochar. Essentially the volatiles in the biomass are off-gassed and condensed into bio-oils, leaving quantities of bio-oils or biochar depending on pyrolysis technology. Canada is a global leader in fast pyrolysis.

The syngas that is produced in pyrolysis systems are usually used internally as input fuel into the pyrolysis process; hence other fuels (natural gas, propane) are only required at startup.

There are currently two main variations of pyrolysis: fast pyrolysis and slow pyrolysis; although many different types of pyrolysis techniques are possible depending on the speed, temperature and amount of oxygen used in the process.69 Fast pyrolysis involves rapid heating and cooling to maximize the yield of bio-oil (about 60–75% by weight) and restricts the production of the secondary products of syngas and biochar. Slow pyrolysis uses lower temperatures and longer durations and maximizes biochar from the system. The exact fraction of bio-oils versus biochar depends on the temperature and reaction time of the pyrolysis process.

Figure 27. Fast and slow pyrolysis

69 As mentioned above, carbonization (torrefaction) is out of scope of this work


Fast (flash) pyrolysis and bio-oils

Fast pyrolysis technologies currently appear to be more promising than slow pyrolysis systems. It essentially converts the energy in biomass into liquid form.70 Some companies have developed pyrolysis to a market-ready technology and research is ongoing at universities and research institutions worldwide. While bio-oil plants are operating in several locations, the B.C. analysis concludes “their economics are not always favourable and will depend on local circumstances or subsidies.”71

Bio-oil is a dark brown liquid with approximately the same energy content as the original biomass but about half the heating value compared to conventional heating oil. Bio-oil can be burned directly (i.e. replacing Bunker C fuels), with some adjustments required for the conventional boiler, co-fired with other fuels, gasified or otherwise upgraded to other biofuels. Bio-oil composition and characteristics can change drastically based on the characteristics of the biomass feedstock and the pyrolysis conditions (temperature, duration).

Slow pyrolysis and biochar

The traditional and largest solid biofuel market has been the production of charcoal, but newer pyrolysis technologies are being introduced that produce biochar which can be added to soils to promote plant and tree growth by helping the soil retain nutrients and water. This newer technology produces a biochar that is a very stable form of carbon and has the potential for significant contributions to GHG management, carbon sequestration and forest productivity; however, the process remains untested at a commercial scale and more research is needed to verify its benefits.

Biochar and charcoal terminology is often intertwined. They are similar products, both produced by the combustion of biomass in an oxygen-restricted environment, but there are few notable differences:

• Biochar can be produced from many different biomass feedstocks while charcoal has traditionally been made from wood and some agricultural residues

• Charcoal is made at temperatures around 350ºC where biochar is made between 450–700ºC, requiring different technologies and processes

• Charcoal is traditionally used as a heating fuel, while biochar is seeing new applications as a soil additive to sequester carbon and improve soil properties.

Although the process of making charcoal is relatively simple and has been practiced in its simplest form for thousands of years, slow pyrolysis technologies are still in development. Although some companies label their technologies as commercial, this research concludes that most are not. Technology robustness and commercialization are still several years away, especially for small-scale systems. Some companies have also had technical hurdles for slow pyrolysis and have switched to torrefaction technologies.

70 BIOCAP 2008, An Informational Guide on Pursuing Biomass Energy Opportunities and Technologies in British

Columbia. 71 Ibid., 30.


There are several national and international organizations that are focused on the advancement of biochar technologies and products including the Alberta Biochar Initiative,72 Canadian Biochar Initiative,73 the British Biochar Foundation74 and the International Biochar Initiative.75


Pyrolysis systems generally require the same feedstock characteristics as gasification systems with one notable difference: they require dryer biomass, with moisture content of around 20%. This low moisture content will make it difficult for any small-scale operator that wants to use their own feedstocks as it would likely require active drying techniques to reduce the moisture content.


There are likely not many applications of bio-oils for small-scale forestry operations as most fossil fuel used for heat is natural gas. Upgrading pyrolysis oil to second generation biofuels through different synthesis processes (i.e. Fischer-Tropsch) is not yet commercial at a small-scale.

Biochar is the most immediate application for small-scale forest operators who are also involved in tree harvesting or forest management. Using biochar as a soil amendment (or in greenhouses) is the most likely fit. However, there is still much debate and scientific research on the environmental benefits of biochar as a soil enhancer. Research continues as governments, institutions and companies work on showing the added value biochar gives to soil productivity.


Pyrolysis oils do not have high commercial value, so unless there is a direct application on site, it will not be cost effective considering transportation distances. Research is ongoing and there are development efforts that focus on upgrading bio-oils into higher value chemicals or hydrocarbon-like biofuels (by treating with hydrogen), but these technologies are still in R&D phase.

4.4.5 Technology examples

Most technology companies on the bio-oil end of the pyrolysis spectrum are working on systems that produce a bio-oil that can be upgraded to second generation biofuels. These systems are still in development and are often very large scale. The main Canadian technology companies researching, developing and providing pyrolysis technologies are Dynamotive Energy Systems, Ensyn Group, BTG Technology Group and ABRI TECH. These are all large-scale systems that

72 http://albertabiochar.ca/ 73 http://www.biochar.ca 74 http://www.britishbiocharfoundation.org/ 75 http://www.biochar-international.org/


will not be applicable to small-scale forestry operators. Below is a very short summary of two of these companies:

• Dynamotive Canada (http://dynamotive.com/) – developing a fluidized bed fast pyrolysis system, with two demonstration plants in Canada. Company is focused on producing bio-oils which can be upgraded to jet fuel, gasoline and diesel.

• Ensyn Group Inc. (http://www.ensyn.com) – developing a fast pyrolysis system using their proprietary RTP technology focused on the production of bio-oils. They have a 100 tonne / day demonstration plant in Renfrew, ON. Their RTP technology platform has resulted in 30 commercialized plants producing a variety of bio-products.

Biochar can actually be produced using very simple technologies and equipment; in fact, searching online for “making biochar in your backyard” gives several helpful results, such as http://backyardbiochar.net/ which has several tools and information guides. So, while a simple process, the challenge is to clarify if biochar does indeed increase soil fertility and can sequester carbon long term, and if there is economic or ecological return on the effort.


5. Bioenergy technology examples – small-scale forestry

The following examples capture some actual bioenergy technology installations specific to the forestry sector in Canada and the U.S.

5.1 Revelstoke Community Energy Corp.

The City of Revelstoke and Downie Timber mill formed B.C.’s first wood-fired district energy system in 2006 where much of the downtown core is heated from utilizing the waste wood from the sawmill. The community benefits from reduced GHG emissions, lower energy costs and increased energy security for the town.

Table 10. Revelstoke Community Energy Corp – example details

Bio-technology category Direct thermal combustion for district heating

Application District heating for space heat and process heat for downtown customers, steam for the dry kiln at Downie sawmill

Technology details Waste wood boiler. Fully-automatic with cyclonic and electrostatic precipitators to remove particulate air emissions

System capacity 1.5 MW boiler with 1.75 MW backup propane boiler

Conventional system replaced

Propane-fired boiler and electric heat

Feedstock type Wood waste (sawdust, shavings) from Downie sawmill

Feedstock storage Unknown

Feedstock volume 7,000 tonnes waste / year

Cost savings Unknown

5.2 Chisholm Lumber

Chisholm Lumber located in Tweed, Ontario uses its waste wood to provide heat to its lumber kilns. The opportunity arose when a fire destroyed the two kilns and Chisholm Lumber had to rebuild its infrastructure.

Table 11. Chisholm Lumber – example details

Bio-technology category Direct thermal combustion for on-site heat

Application Space heat and process heat (kiln drying – 100,000 board feet)


Technology details Waste wood boiler by Grove Wood Heat (http://www.eco-blaze.com/index.php), PEI. Semi-automatic (waste wood is moved from storage to hopper by a tractor with front-end loader).

Boiler heats hot water and heat exchanger used in heat kilns

System capacity 350 kW


Oil-fired boiler

Feedstock type Mixture of green sawdust, shavings

Feedstock storage Fuel storage bin – 2.5m x 3.7m x 2.5m

Feedstock volume 2-3 tractor trailer loads / month

Cost savings $18,000 / year

5.3 Madsen’s Custom Cabinets

Madsen’s Custom Cabinets located in Edmonton, Alberta uses its waste wood to provide space heat to its entire facility. The opportunity arose when the owner’s daughter did a research case study for university on waste heat possibilities for their operation.

Table 12. Madsen’s Custom Cabinets – example details

Bio-technology category Direct thermal combustion for on-site heat

Application Space heat (30,000 ft2 facility)

Technology details Waste wood boiler - KOB boiler

System also has two other components:

• wood grinder to reduce the size of larger waste wood pieces

• briquetter to compress sawdust

System capacity 540,000 kW


Natural gas boiler

Feedstock type Wood scraps, shavings, sawdust. Sawdust pressed into briquettes (5cm x 5cm).

Feedstock storage Unavailable

Feedstock volume 300 tonnes / year

Cost savings Virtually no natural gas usage. Cost negative as company usually had to pay for their waste wood removal.


5.4 Buchkirchen co-operative wood chip district heating system

A co-operative district heating systems located in Buchkirchen, Austria and started by four farmers in 2006.

Table 13. Buchkirchen co-operative district heating system – example details

Bio-technology category Direct thermal combustion for district heating

Application District heating to clients 1.8 km away (25 customers) using underground hot water transfer

Technology details Fully automatic wood chip boiler

System capacity 650 kW, 150 kW


Oil boilers

Feedstock type Wood chips from forest thinnings


Feedstock volume 1,200 – 1,400 tons / year

Cost savings Unavailable

5.5 Lathrop Forest Products

Lathrop Forest Products, located in Bristol, Vermont, switched business models and operations in 2006 from a sawmill operation to a supplier of wood chips. The opportunity arose when the owner saw several sawmills going out of business and one of his main mills burned down. Owner decided he needed to establish a new business model.

Table 14. Lathrop Forest Products – example details

Bio-technology category Wood chipping and supplying wood chips. Wood chips come from low quality sawlogs, logging slash and fast-growing poplar and pine.

Application Supplying wood chips to a power plant, paper mill and schools

Technology details Supplies wood chips to:

• 50 MW wood fired power plant

• Large college

• A dozen local schools

System capacity Wood fired power plant – 50 MW


Client’s chip boiler systems replace oil boilers

Feedstock type Wood chips – logging slash and bole chips (whole trees)



Feedstock volume Supplies 50,000 tons / year

Cost savings Unavailable. One high school saved $75,434 in one year

5.6 Hallander’s Sawmill and village district heating

Hallander’s Sawmill, located in Dalstrop, Sweden, uses its own sawmill residues to generate and supply heat to its kiln operation as well as for the village of Dalstrop through district heating.

Table 15. Hallander’s Sawmill and village district heating – example details

Bio-technology category Direct thermal combustion for onsite heat and district heating

Application Process heat for kiln drying and district heating to a community 7km away (150 customers) using underground hot water transfer

Technology details Järnforsen woodchip boiler with multi-cyclone for reducing air emissions.

System capacity 5 MW


Electric heat, natural gas

Feedstock type Bark, sawdust,


Feedstock volume Unavailable

Cost savings Unavailable


6. Case Study – Harrop-Procter Community Forest

Harrop-Procter Community Forest, located just outside Nelson in the West Kootenays, is an FSC-certified community forest co-operative that focuses on the ecological integrity of its managed forests. The co-operative was established in 1999 and holds license to 11,300 hectares of forest in the Selkirk Mountains. The community forest is developed according to ecosystem-based planning principles.

Harrop Procter Forest Products (HPFP)76 is the sawmill and forest product company that mills the logs harvested from the community forest. It produces trim, timbers, siding, decking, flooring and other wood products. The mill has a band saw, edger, molder and a dust collection system. There is also a kiln for drying timber, a small office and a larger unheated storage building recently built to store their timber. HPFC also has telehandler and a forklift that operate on diesel.

The electrical supply at HPFP is only single-phase power as three-phase power would require a significant capital upgrade by the mill ($100,000). With this limitation, a maximum of 50 horse-power (HP) electrical equipment can be used.

6.1 Timber production and waste wood

HPFP mills approximately 1,100–1,300 m3 of wood per year, predominantly from Red cedar, pine and Douglas fir. It is estimated that the current milling operation results in approximately 481 m3 (37%) of the wood going to waste, predominantly as sawdust (33% of the waste) and slabs (67% of the waste). It is estimated that about 10% of the wood waste is bark. Typical sawdust and slab piles at HPFP are shown in Figure 28.

76 http://www.hpcommunityforest.org/forest-products/


Figure 28. Waste sawdust and slabs – Harrop Procter Forest Products

Current management of their waste wood varies is as follows: their sawdust is typically given away for free to locals (animal bedding, riding rings, topsoil product) and any leftover sawdust is distributed back to the forest tenure area. Cedar sawdust is problematic because it is acidic and is not always a sought after material. Sawdust is collected through their site dust collection system into an on-site 360-ft3 trailer that is filled twice a week for 40 weeks of the year.

Slabs are either given away for free or burned when venting regulations permit burning.77 More recently, since management advertised the slabs as free giveaway, all slabs have been taken and management has not had to deal with slab pile burning in 2014. In 2013, slab burning occurred three times as shown in Figure 29. Slab burning has been tolerated by the community but there is a sense that people don’t like it. Slab burning requires fire management (sprinklers), creates significant soot and burn debris and also creates holes in the tarps that are used to cover the finished timber.

Figure 29. Slab pile after burning

Regardless of where the waste wood goes, dealing with it is a burden. For a few years now the management has been looking for alternative means to realize the economic value in their waste

77 http://www.env.gov.bc.ca/epd/epdpa/venting/venting.html


wood. There has been interest in the past in looking at biochar applications to deal with the waste wood; both as a solution to the management burden of the waste with the added benefit of using the biochar as a soil enhancer for their community forest.

Table 16 summarizes the annual amounts and volumes of waste wood at HPFP.

Table 16. HPFP – waste wood volumes and energy content

Parameter Slabs Sawdust Total

Volume (m3/ yr) 322 815

78 N/A

Weight (BDT / year) 140.2 68.9 209.1

Energy content (GJ / year) 2,523 1,241 3,764

Using the very simple financial analogy of $50/BDT, the gross economic value of HPFP’s waste wood could be $10,457 / year, and higher if higher value products could be made from the waste (i.e. pellets)

6.2 Potential products and application opportunities

From the list of biotechnologies scanned, the following are technologies and products / applications that may be practical and in the interest for HPFP to explore.

6.2.1 Pre-processing – debarking

In conversation with HPFP, it was stated they had recently investigated and determined that a debarker was not financially viable. However, debarking may present an opportunity when adding a bioenergy application. Currently HPFP mills all their logs with bark attached and end up with slabs with both bark and white wood. Debarking could increase the volume of timber produced for their main operation and would result in a separation of bark and white wood. The bark could be separately sold or given away for possible mulch, animal bedding or other uses.

The white slabs would then present an opportunity to produce wood chips for on-site consumption or to sell as a commodity to a local market (see next section).

Based on the current 1,300 m3 / year of logs being milled, small-scale debarkers similar in capacity to the Morbark rosserhead debarkers would be a good fit. The Morbark 640 debarker will accept both softwoods and hardwoods. It can process logs between 6” and 40” in diameter and can debark at 100 linear feet / minute. They Morbark can come in either electric or diesel configurations, with the electric having a 50 HP configuration (maximum for HPFP electrical system). The debarker is 53’ in length and would require a fair amount of space to handle longer logs. It is unknown whether space would be available at the mill that would not impede the flow of the milling operation.

78 Higher number than expected because of the energy density of sawdust (210 kg / m3 used)


Challenges

Challenges for this opportunity include:

• Finding appropriate space near the sawmill that is big enough for the selected debarker and will not impede the flow of the milling operation. The integration of debarking should cause minimal additional log handling time for the main milling operation. The space required for the debarker will vary depending on the design of the debarker and the desired length of logs debarked. Longer logs (greater than 16 feet) will likely require large debarkers that have intake and outtake troughs.

• Maintenance and operation – additional labour would be required to operate the debarker, and maintenance / part replacement should be expected.

• Finding a debarker that can operate on Phase 1 electricity with a maximum of 50 HP.

• A debarker would only be part of the solution for a bioenergy application. A chipper would most likely also be needed to produce white wood chips for thermal combustion applications.

• Finding the appropriate capital for the debarking system.

6.2.2 Pre-processing – chipping

Chipping of the waste slabs present an option for HPFP. Chipping could be done on either the current slabs (bark and white wood) or slabs produced after debarking. Each of these would result in chips of different quality and characteristics, and these chips could have different end-use applications. Chips with a bark component could be used for a commercial direct thermal combustion system and white chips could be used for a gasification or pyrolysis system.

Chipping of unmerchantable logs might also present an opportunity but the mill does not receive many unmerchantable logs.

Based on the annual volume of slabs produced (322 m3), chipping the slabs could be accomplished by the small-scale chipper highlighted in Section 3.2.5; however even these chippers might be too large for slab-only application as most of the chippers outlined have the capacity to process full logs. An electric chipper or diesel power chipper could be used depending on the goals of HPFP. Since HPFP runs on only single-phase, a chipper that meets this electrical requirement would be required.

Approximately 420 m3 (G50 specification) of wood chips would be produced annually from the 322 m3 of slabs; more if unmerchantable logs were to be chipped. Only a small portion of these chips would be needed for on-site heat applications, so this would likely not be the best option — if on-site heat is needed, it is likely best to use a cordwood or hog boiler. The more likely use of chips would be to use them for a district heating system (see section below) or to sell them to a local market.

A viable local market could possibly be the City of Nelson which is exploring a district heating system utilizing wood chips. The entire annual production of wood chips that could be produced


by HPFP represents approximately 3% of the estimated wood chips required by the City.79 In order to satisfy a long-term supply contract, HPFP could look at the possibility of teaming up or forming a co-operative with other small-scale forest operations to increase the amount of wood chips that could be supplied in order to supply a substantial amount of wood chips. If producing wood chips for the City, a wood chipper must be selected that produces chips which meet the specification defined by the City. The quality of wood chips and other characteristics that will be required by the City is not known at this point.

Regardless of wood chip usage or destination, on-site storage would be needed to keep the wood chips dry and free of contamination. Manual drying of the wood chips to reduce the moisture content would be an advantage. A covered chip storage bin, either underground made of cement or above ground, would be an acceptable solution.

Challenges

• Selecting an appropriate chipper that is adequate for the desired waste wood (slabs or unmerchantable logs). Smaller chippers might not produce chips that will meet the requirements for bioenergy chip systems. Care should be taken when researching the appropriate chipper and the quality of chips produced.

• Mobile or stationary – there are different advantages of smaller mobile chippers compared to larger stationary chippers. The desired use of the chipper should be determined first. A mobile chipper could be used in the logging operations to chip unmerchantable species.80

• Maintenance and operation – Additional labour would be required to operate the debarker, and maintenance / part replacement should be expected.

• Noise – some chippers do generate substantial noise and this should be taken into consideration. It is not likely a major concern considering it will be part of the sawmill operation.

• On-site fire risk prevention strategies and equipment must be considered when storing chips.

• Raising the appropriate capital for the chipper systems and ensuring the business case is viable.

6.2.3 Pre-processing – wood pellets

Considering the amount of sawdust generated from the milling operation, the potential exists for using that sawdust to produce wood pellets. The sawdust is already in the proper form for pellet production; however, some additional passive drying might be needed. Pellets derived from the sawdust could be used for residential heating applications.

79 Estimate based on mid-range annual requirement of wood chips stated in Nelson bioenergy feasibility study 80 The specific harvesting of unmerchantable species for use in bioenergy applications is not supported by the Pembina Institute because carbon accounting suggests that this process does not result in a net reduction in greenhouse gas emissions. Only logs that have been harvested for the purpose of milling and later realized to have defects that made them unmerchantable should be used in this process.


If a market for lower-quality commercial wood pellets can be found, there might be viability in chipping the waste slabs into very fine chips or sawdust to press into pellets. There are a few bioenergy chippers on the market (i.e. Bandit Beast Recyclers Model 3680) that chip material fine enough to press pellets but these are larger systems and may not be suitable for small-scale forestry operators generating a small amount of waste.

Based on the annual amount of sawdust produced, a wood pellet system with capacity of 40–60 kg / hour would be more than satisfactory (and even on the high end) to process the sawdust. Approximately 58 tonnes of wood pellets per year could be produced. At $300 / tonne (average cost of residential wood pellets), the economic potential of wood pellets is $17,364 / year.

Challenges

• Finding / developing a market for residential wood pellets and/or pellet stoves. The West Kootenay Regional District is part of B.C.’s Provincial Wood Stove Exchange Program81 and pellet stoves are included in this program. There may be an opportunity to work with this program to promote wood pellet stoves in the region.

• Pellets will need to be bagged and stored indoors – a bagging system and storage facility will be required.

6.2.4 Pre-processing – wood briquettes

The same opportunities as wood pellets exist for wood briquettes, although the feedstock quality would be lower and the target market would be different. Target markets for developing wood briquettes include more commercial systems – and possibly local businesses such as pizza ovens and fish/meat smokers.

6.2.5 Direct thermal combustion for heat opportunities – process heat

An on-site direct thermal combustion system for heat could be utilized; the most likely application for this would be to provide heat to their kiln as the mill has minimal space heating and hot water needs. Either a hog boiler capable of burning slabs or a chip boiler could be utilized; on-site chipping would be required for the latter, and there might be better economics in selling the chips if a market can be found.

The amount of electricity used by the kiln is very roughly estimated at 24,000 kWh/yr. The amount of slabs needed to provide this heat is quite insignificant — less than 1% of the annual amount of slabs produced. Therefore it does not likely make business sense to invest in a direct thermal system to provide heat to the kiln.

6.2.6 Direct thermal combustion for district heating opportunity

Although HPFP is not in located in an urban setting, there are a few interesting opportunities for district heating.

81 http://www.bcairquality.ca/topics/wood-stove-exchange-program/individuals.html#choose


PRT Nursery

Located very close to the HPFP is the PRT greenhouse nursery. Biomass heating has been lightly explored in the past and no viable economic solution has been found as major retrofits would be required. The PRT nursery consumes a large amount of natural gas and a large biomass system would be required.

Based on information received during a phone conversation with PRT82, the entire waste wood generated at HPFP would meet only 15% of the energy requirements of the nursery. There is one smaller greenhouse in the nursery (on the north side of the road) that consumes only a fraction of the natural gas and heating this greenhouse with a biomass system could be something to explore. Rough estimates are that the entire waste wood generated at HPFP could supply 70% of heat for this greenhouse. It would be a tremendous win for developing a project that achieves several of the environmental, economic and social benefits of utilizing very local waste wood.

Procter Old Schoolhouse

The Procter village and Old Schoolhouse is approximately 9 km down the highway from HPFP. Pembina recently conducted an energy audit and analysis on the Old Schoolhouse, which is an electrically heated 4,588 ft2 building. Adjacent to the schoolhouse is the Procter Community Hall which is heated with propane. There is also a general store in the area and some residential homes. Although this would be a fairly small district heating system, and major retrofits to the heating system would be required for the schoolhouse, it represents a really interesting opportunity and an excellent match between a local waste wood supply and demand in a semi-rural setting. There is a small amount of space between the Procter Hall and the Old Schoolhouse that could be utilized for a small direct thermal heating plant that could provide heat to the buildings.

82 Personal communication with Ray Bagell, Nov 12 2014


Figure 30. Downtown Procter

6.2.7 Thermal-chemical conversion – biochar

Since HPFP is part of the Harrop-Procter Community forest, utilizing their waste wood for biochar production is an opportunity to apply the benefits of biochar to their community forest’s soil. However, no commercial technologies available on the market seem viable for HPFP needs. Very simple, backyard biochar systems could be utilized,83 but HPFP would need to be willing to invest in a system and have confidence that the biochar produced would indeed increase soil fertility in their community forest. Selling biochar will likely be challenging as education would be required to demonstrate and explain the benefit of biochar.

83 http://backyardbiochar.net/


7. Summary and Recommendations

7.1 Commercial state of small-scale biotechnologies

The state of commercial small-scale bioenergy technologies that are applicable to small-scale forest operations in the Kootenays vary. Below is a summary of the current technology state as determined in this research.

• Pre-processing – There are many mature, small-scale debarkers and chippers in a variety of configurations (electric-powered/diesel-powered, mobile/stationary, drum/ring). However, most are still tailored to the forestry industry; some companies offer machines that have bioenergy applications in mind but their products may not meet wood chip specifications (G30/50, CEN/TC 335). Incorporating pre-processing of waste wood into forestry operations and upgrading waste streams into useable products — most notably chips — could be a relatively simple technical undertaking.

• Densification – Several mature technologies for the production of wood pellets and briquettes. Production ranges from a few thousand kg/hr to several hundred; a few are very small-scale, backyard systems. Most wood pellet and briquette presses have roots in the agriculture and animal feed industry. Wood pellets are ideal if the waste wood is predominately sawdust or fine shavings. If not, additional pre-processing (chipping) will be necessary as only some small-scale systems have integrated pre-processing capabilities. Also, feedstock would need to be dried as moisture content of pellet/briquette feedstocks is required to be ~ 20%. Upgrading a waste feedstock to pellets or briquettes results in approximately doubling the economic value of the waste wood.

• Direct thermal combustion for heat – Significant number of mature, proven small-scale mature technologies that come in a variety of configurations and applications — wood stoves, cordwood/hog fuel boilers, pellets stove/boiler and chip boilers. All can be used for a variety of applications included space heat, water heating and process heating. This classification of system represents the most plausible usage of biotechnologies for small-scale operators. Feedstock quality can be low for hog fuel (high percentage of bark, non-uniform), medium for chips (but best to use chips that meet the specification of the boiler) and high for pellet systems.

• Direct thermal combustion for power – ORC systems are only the viable technology for small-scale applications. Fewer commercial systems are available compared to direct thermal combustion for heat. Most ORC systems are designed for larger-scale (5 MW and greater) but small scale (<200 kW) are available.

• Gasification for power – There are limited small-scale gasification for power systems available and European companies seem to be ahead of North America in offering commercial systems. Gasification for power systems require an IC engine as well, leading to


higher capital costs and maintenance costs. Gasification for power has various benefits and drawbacks compared to ORC systems.

• Pyrolysis for bio-oil and biochar – An evolving market and technology; small-scale pyrolysis systems are still in development with different companies focusing on a variety of fast and slow pyrolysis technologies. There is a gap in robust, commercialized systems applicable to small-scale forestry operations; bio-oils have limited applications in this space and there is ongoing debate on the carbon benefits or soil production benefits of biochar.

Table 17 summarizes the technologies researched.

Table 17. Commercial state of small-scale biotechnologies – summary

Legend

Commercially-sound technologies; products are available in the marketplace

Commercially-sound technology but product availability in Canada is limited

Technology may not be commercial; positive economics questionable

Inadequate robust commercial technology available; projects are limited and/or require significant government funding

Technology Technology status

Availability of small-scale technologies*

Additional info

Pre-processing – debarking

�� • Many available technologies • More products needed specifically for bioenergy

applications • Debarking only helpful if there is a market for white

chips and process can be integrated with core business

Pre-processing – chipping

�� • Many technologies available; vary in quality of chip produced

• More products needed specifically for bioenergy applications

• Best use for brown chips is on-site direct thermal combustion for heat / power

• Best use for white chips is sale as commodity if market can be found

• Possible application of white chips for gasification / pyrolysis if those technologies improve

Densification – pellets

�� • Small-scale pellet mills are available based on animal feed industry

• Producing pellets require sawdust and low moisture content (< 20%)

• Currently limited market opportunity in RDCK

Densification – briquetting

�� • Briquetting systems are more prevalent than pellet systems, and overall simpler in design and complexity

• Producing briquettes require sawdust / shavings with low moisture content (< 20%)

• Briquettes have niche heating application: space


heating, possible commercial applications

Direct thermal combustion for heat

�� • Plethora of available technologies and applications, all robust and mature: stoves, cordwood boilers, pellet stoves / boilers, chip boilers

• Can utilize a variety of feedstocks from unprocessed (hog fuel) to fully processed (pellets), with a variety of characteristics

Direct thermal combustion for power (ORC)

�� • Mature technology, but limited options available at low capacity (<250 kW)

• On-site power generation possible, but connecting to grid will require net metering program that RDCK utilities currently don’t provide

• Can use semi-clean feedstocks – brown chips, white chips

• Very low efficiency (< 15%) – requires significant feedstocks for limited power production

Gasification for power

�� • Very limited small-scale gasification systems available in Canada

• Downdraft gasifiers are best match for small-scale forest operators

• Low efficiency (~ 25%) • Requires clean high quality feedstocks (white chips —

can be combined with sawdust)

Pyrolysis

� • Fast and slow pyrolysis technologies; fast pyrolysis geared towards the production of bio-oils; slow pyrolysis geared towards biochar

• No small-scale commercial technologies appear to be available; all research and product offering are for larger systems that focus on bio-oil upgrading to renewable fuels

*Note: � few small-scale technologies available;

�� large number of small-scale technologies available

7.2 Feedstock requirements

The most appropriate choice of technology is most driven by the characteristics and availability of waste wood feedstock. Table 18 summarizes the best match for waste wood resources and available technologies.

Table 18. Waste wood resource and most appropriate technology – summary

Biomass resources

Best technology Best product / application

Maximum moisture content

Quality and consistency of fuel needed

Hog fuel

Direct thermal combustion (hog boiler)

On-site heat or district heating

50 – 60% Low

Pre-processing Chipping 50 – 60% Depending on end-use of chips

Slabs

Direct thermal combustion (hog boiler, cordwood boiler)

On-site heat or district heating

50 – 60% Low

Pre-processing Chipping 50 – 60% Depending on end-use of chips


Sawdust, shavings

Sawdust, shavings

Briquetting, direct thermal combustion

Selling briquettes, on-site heat

15%, ideally 10%

Medium

Pelletization, direct thermal combustion

Selling chips, on-site heat

15%, ideally 10%

Medium for brown pellets, high for white pellets

Wood chips (through pre-processing)

Direct thermal combustion, ORC, gasification

On-site heat, on-site power, selling chips

Maximum 35% (Lower the better), 15% (for gasification)

Medium, high for gasification

Pyrolysis Bio-oil, biochar 15% High

7.3 Technical resources

Table 19. List of technical resources

Resource Website / URL

The Beginners Guide to Pellet Production

http://www.pelheat.com/How_To_Buy_A_Quality_Pellet_Mill_PelHeat.pdf

Buyer’s Guide To Biomass Combustion Systems

http://publications.gc.ca/collections/Collection/M92-186-2000E.pdf

Biomass Boiler Buyers Guide

http://www.canadianbiomassmagazine.ca/images/stories/2011/mayjune11/biomassboilerbuyersguidelr.pdf

Biomass Heating: A guide to small log and wood pellet systems

http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/BEC_TECHNICAL/BEST%20PRACTICE/36491_FOR_BIOMASS_1.PDF

Biomass Heating: A guide to medium scale wood chips and wood pellet systems

http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/BEC_TECHNICAL/BEST%20PRACTICE/37821_FOR_BIOMASS_2_LR.PDF

Biomass Heating: A guide to feasibility studies


Biomass Heating: Tools and guidelines


Biomass Heating: A practical guide for potential users

http://www.carbontrust.com/media/31667/ctg012_biomass_heating.pdf

Small-Scale Biomass District Heating Handbook

http://www.toolkit.bc.ca/Resource/Small-Scale-Biomass-District-Heating-Handbook

7.4 Recommendations – next steps

The following next steps are recommended to further the work initiated in this research:

• Present these results to interested small-scale forest operators to gauge their interest and to identify opportunities that might be a good match to their waste wood challenges


• Connect with and present these findings to the various organizations that are working on local environmental, economic and social issues in the West Kootenays, including: Waste Wood to Rural Heat Project, SIBAC, Selkirk College Rural Development Institute, CBT’s Alternative Energy Steering Committee, Ministry of Industry, Trade and Tourism

• Further refine the results to better distinguish those best suited for small-scale operators and medium-scale sawmill operations; different opportunities will exist depending on the different amounts of waste wood

• Further the economic analysis in this research; research the financial viability and opportunities for local bioenergy products and applications

• Research potential markets for the various bioenergy products and applications

• Expand this work to investigate the technical and economic potential for in-forest logging slash

7.5 Debrief meeting with Harrop Proctor Forest Products

A debrief meeting was held on April 30, 2105 with HPFP to review the findings of this study and discuss possible next steps to advance the mill’s thinking and opportunities for using their biomass waste stream. The meeting highlights are summarized below.

• Debarking – debarking is an attractive option for the mill; removing the bark from logs extends the lifetime of the bands on the bandsaw and the cutter heads on the molder. Fir bark could be exclusively harvested which has the potential for good economic value for landscaping material. The white slabs produced could further be processed into white pellets, briquettes or could even be diverted to the pulp and paper industry.

• Greenhouse heated with biomass boiler – Not considered in the case study for HPFP, but there is interest in a greenhouse on the grounds that could benefit the local community. There would be support at HPFP if there is a viable business case for a biomass heated greenhouse to extend the late summer growing season and provide a space for community members to grow their starter plants in the spring. An additional possibility is to include some office attached to the greenhouse for the staff at HPFP that is heated with a biomass boiler.

• Wood chipper for space heating – Another opportunity identified was to chip the waste slabs for a biomass boiler to provide space heat for the Procter Community Hall which is about 10 km away. This would be a great synergy between using local waste from a community forest and providing this waste to reduce fossil fuel usage (propane) in a community building.

• Production of charcoal – Interest was expressed to produce very basic charcoal for local usage – barbeques, artisans (iron workers, ceramic kilns). There was the thought of purchasing very simple, proven charcoal producing equipment (that uses slow pyrolysis) to generate the charcoal.

Discussions with HPFP will continue around the best strategy to move the feasibility of the best option(s) forward.