Woody Debris Characterization Study Wood Waste to Energy Facility for Tomslake/Kelly Lake
Prepared for:
Kelly Lake Metis Settlement Society
&
Waste to Energy Canada
June 29, 2012
Reed Environmental
548 Cornwall Street
Victoria BC, V8V 4L1
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Table of Contents
1.0 Introduction ............................................................................................................................... 3 2.0 Background ............................................................................................................................... 3
3.0 Methodology ............................................................................................................................. 8 4.0 Limitations and Assumptions ................................................................................................... 9 5.0 Results ....................................................................................................................................... 9 6.0 Summary and Recommendations ........................................................................................... 13 7.0 Appendices .............................................................................................................................. 15
Credits and Disclaimer
Reed Environmental would like to thank Blake Bowden, President of Bowden Holdings, for his input and review of this report. Reed Environmental takes full responsibility for any errors or omissions in this report.
Report Prepared By:
Nygil Goggins, MRM
Senior Project Manager
June 29, 2012
Report Reviewed By:
Jesse Ketler, MSc
Senior Environmental Consultant
June 29, 2012
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1.0 Introduction
Reed Environmental has been commissioned by the Kelly Lake Metis Settlement Society
(KLMSS) and Waste to Energy Canada (WTEC) to deliver a Woody Debris Characterization
Study for the Kelly Lake/Tomslake region.
The primary objective of this study is to characterize the available woody debris within an
economically viable radius of the proposed site for WTEC’s Continuous Gasifier System (CGS)
plant. The annual supply of woody debris in the region is defined and categorized based on the
following parameters:
annual supply;
long term (30 year) supply risk;
moisture content;
bulk density;
calorific value; and
delivered cost.
These results will be used to both inform the Front End Engineering Design (FEED) and assess
project feasibility. The FEED will include a refinement of the available biomass supply and the
total delivered cost. Recommendations to support the FEED and project feasibility study are
presented in Section 6.
2.0 Background
The proposed site is located in the south eastern portion of the Dawson Creek Timber Supply
Area, which closely aligns with the South Peace Regional District (Figure 1 and 2). The site is
located approximately 10 km southwest of Tomslake.
Approximate driving distances from the site to other major centers:
Dawson Creek: 30 km
Chetwynd: 130 km
Fort St John: 110 km
Grande Prairie: 110 km
Mackenzie: 230 km
The coniferous forest to the southeast of the site is predominately a mixture of pine and spruce.
Within these stands there is a significant amount of dead standing pine from the mountain pine
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beetle outbreak and small diameter pulp grade timber1. Competition for pulp grade timber (dead
standing or <6 inch diameter) southeast of the site will be limited due to the distance from local
mills.
Figure 1: Site location in relation to local communities, sawmills and forest type
2
The Dawson Creek Timber Supply Area (TSA) has a harvesting land base of approximately
730,000 ha and an annual allowable cut of approximately 1.86 million m33. The forest
composition in the TSA is 65% coniferous and 35% is deciduous, of which:
35% is white spruce;
24% is lodge pole pine;
6% is sub-alpine fir;
29% is aspen; and
6% is poplar.
Tree Farm License (TLF) 48 (Chetwynd) is held by Canfor with an AAC of 900,000 m3/year
(2007), of which 800,000 m3 is coniferous and 100,000 m3 is deciduous.4
1 Information provided by Bowden Holdings, a local biomass supply contractor
2 Adapted from: http://atlas.nrcan.gc.ca/auth/english/maps/environment/forest/useforest/sawmills
3 http://www.for.gov.bc.ca/hts/tsa/tsa41/
4 http://www.for.gov.bc.ca/hts/tfl/tfl48/tsr3/48tf07ra.pdf
Site Location
Coniferous
Forest
Deciduous
Forest
Mixed
Forest
Sawmills
Site Location
Coniferous
Forest
Deciduous
Forest
Mixed
Forest
Sawmills
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Figure 2: Dawson Creek TSA and TFL 48 boundaries
The Feedstock Availability Study (Appendix A) identified five mills in the region with a
combined annual allowable cut (AAC) of 3.4 million m3 per year (see Table 1 below). Mill
residues (bark and sawdust) are now sold by mills due to the increased demand for this
feedstock. Mill residues are used as hog fuel for process heating and bio-energy, feedstock for
pulp a paper and wood pellets, and as bedding and mulch in the agriculture industry. The
availability and price of this feedstock is dependent on mill production levels and regional
demand for mill residues.
The amount of biomass residue left as road side waste from logging operations varies from 0-
15% of the total AAC on a site by site basis. As a result, collection costs can vary significantly
from site to site. The forest tenure system can create challenges for accessing roadside waste on
a company’s tenure due to concerns over liability. Roadside waste is generally more costly per
tonne delivered than mill residues and pulp grade timber5.
Table 1: Forest products manufacturing facilities in the region
Plant AAC (m3) Approximate Distance
from Site (km)
Owner
Dawson Creek OSB 600,000 30 Louisiana Pacific
Fort St John OSB 1,000,000 110 Peace Valley
Fort St John Lumber 1,300,000 110 Canfor
Chetwynd Lumber 130
Chetwynd Pulp and
Paper
481,000 130 Tembec
5 Based on the experience Blake Bowden, President of Bowden Holdings.
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The West Fraser wood waste to energy plant in Chetwynd will create additional demand for
biomass feedstock in the region when it becomes operational in 2014. According to the plant
manufacturer, 50-60% of biomass fuel will come from local sawmill operations and 40-50% will
come from logging residues6. The two cogeneration facilities in Grande Prairie also add to the
regional demand for biomass feedstock (Table 2). There are currently no pellet plants in the
region, due mainly to the cost of shipping to port for export.
Table 2: Wood waste to energy facilities in the region
Plant Capacity Annual Biomass
Demand (GT)*
Distance from
Site (km)
Owner
Chetwynd Bioenergy
Plant
13 MW
(2014)
180,000 130 West Fraser
Bear Creek
Cogeneration
Grande Prairie
80 MW 800,000 110 Weyerhaeuser
(Operator is
TransCanada
Energy)
Grande Prairie
Cogeneration
25 MW 330,000 110 Canadian Gas and
Electric
*Rough estimates based on demand of CGS plant
Moisture Content and Density
The moisture content of woody debris is a significant cost factor for an energy plant. As the
relative moisture content increases, mass and bulk density increase and the net calorific value per
tonne decreases (Figure 3 and 4). Drier wood is less expensive to transport and provides more
energy per tonne. Wood that is wet may result in a truck reaching its weight capacity before its
volume capacity, resulting in more trips.
6 http://www.pw.utc.com/media_center/press_releases/2012/05_may/05-02-2012_00002.asp
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Figure 3: Net calorific value and mass density versus moisture content
Figure 4: Net calorific value and energy density versus moisture content
Forest biomass is generally sold by the bone dry tonne (BDT), or the equivalent oven dry tonne
(ODT). The approach recommended by FPInnovations is to set the delivery price based on
energy content delivered versus gross weight so payment is based on energy and not water7.
As an example, a truckload of wood biomass with an average moisture content of 40% will have
12% more energy value than a truckload with 45% moisture content. Payment based on ODT
will achieve the same outcome and ensure that the incentive is in place for contractors to deliver
dryer wood.
7 http://www.biomassinnovation.ca/pdf/BradSutherlandHeavyCons.pdf
Net calorific value and density of biomass vs. moisture
content
0
2
4
6
8
10
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22
0% 5%10%
15%
20%
25%
30%
35%
40%
45%
50%
55%
60%
65%
Moisture Content %
Net
calo
rific v
alu
e
GJ/t
0
200
400
600
800
1000
1200
1400
1600
Density k
g/m
3
Wood NetCalorificValue GJ/t
HardwoodDensitykg/m3
SoftwoodDensitykg/m3
Biomass energy by weight and volume vs. moisture content
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
0% 5% 10%
15%
20%
25%
30%
35%
40%
45%
50%
55%
60%
65%
Moisture Content %
Net
CV
GJ/t
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Energ
y d
ensity G
J/m
3
Wood NetCalorific ValueGJ/t
Hardwood chipenergy densityGJ/m3
Softwood chipenergy densityGJ/m3
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Bulk Density
The bulk density of woody debris is another concern for transportation costs as volume limits for
trucks will generally be reached before weight limits, resulting in more trips. A B-Train has a
weight capacity of 40 tonnes and volume capacity of 80 m3. Therefore, if the average bulk
density of material is less than 0.5 tonnes per m3, the volume capacity of a B-Train will be
reached before the weight capacity.
As an example, transporting slash will require twice the number of trips as chipped slash (Figure
5). This is the reason that chipping is generally done at the roadside prior to transport.
Transportation costs are generally the most significant portion (50%) of delivered cost.
Figure 5: The impact of bulk density on volume (Source: FPInnovations)
3.0 Methodology
Biomass Feedstock Availability and Cost
The Feedstock Availability Study (Appendix A) was completed by Blake Bowden, President of
Bowden Holdings. Mr Bowden is a biomass feedstock expert and contractor sourcing biomass
feedstock (chips and stems) for mills in the region. Bowden Holdings has unique experience
sourcing and delivering feedstock in the region surrounding the proposed WTEC CGS plant.
A cutoff of 150 km was selected for the analysis as transportation costs become prohibitive
beyond that distance. The annual biomass supply was estimated based on the AAC in the region
and the area of private land under production. Ratios of tonnes of biomass feedstock generated
per m3 produced were used to estimate the total of each feedstock type. Bowden Holdings based
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the estimates for private land on existing relationships with private landowners. BC Timber
Sales was contacted about the availability of pulp grade timber in the region.
Delivered cost estimates for each feedstock type were generated based on the experience of
Bowden Holdings sourcing and supplying feedstock in the region. Bowden Holdings current
operation costs were used to estimate the average cost per tonne of each feedstock. A literature
review of the delivered cost of biomass feedstock was completed for comparison.
Woody Debris Characterization
A literature review was completed to estimate the moisture content, net calorific value, bulk
density and energy density of the biomass feedstock in the region. The physical characteristics
of wood are well documented, with moisture content and biomass form (ie solid wood versus
chips) having the greatest impact on physical characteristics of concern for an energy plant. The
literature review was reviewed by Blake Bowden to ensure estimates are regionally appropriate.
4.0 Limitations and Assumptions
Biomass Feedstock Availability and Cost
The supply and cost estimates for mill residues are based on the experience of Bowden
Holdings. Mills were not contacted for firm quotes.
The supply and cost estimates for forest residues are averages and there can be significant
variation in the cost of delivered roadside waste.
The available feedstock from BCTS and private land will be heterogeneous in terms of
the physical characteristics and delivered cost. More effort is needed to delineate these
costs given that the current feedstock availability greatly exceeds the plant requirements.
Other sources of feedstock (MSW, agriculture residues, contaminated waste) with
potential tipping fees were not considered in this study.
Woody Debris Characterization
Physical characteristics were derived from a literature review and no sampling was
conducted.
This study did not consider methods for reducing the moisture content of biomass
feedstock. As an example, stock piling of feedstock to control for supply risk could also
reduce moisture content.
CGS plant specifications were not provided and plant performance was not a
consideration of this study.
5.0 Results
Feedstock Availability and Cost
The Feedstock Availability Study (Appendix A) indicates that there are roughly 1.6 million
tonnes of biomass available annually within 150 km of the proposed plant site (Table 3). The
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annual feedstock requirement of 132,000 green tonnes per year for the 10 MW plant represents
8% of the estimated annual supply in the region.
Table 3: Available biomass feedstock within 150km of the site (green tonnes)
The current average delivered cost in the region is $40-45 per green tonne, or $90-104 per ODT,
which is relatively consistent with reports on the price of biomass feedstock in BC (Table 4).
Results in Table 4 are from 2005 to 2008, so an inflation factor of 2.5% was applied. This factor
may understate the inflationary effect of fuel price increases over the past five to seven years.
Table 4: Literature review of delivered biomass feedstock in BC8
Based on the experience of Bowden Holdings, the inflationary effect of fuel prices and labour
generally increase the cost of delivered feedstock by 2.5% annually in the region. Based on this
inflation rate, the lifecycle cost of providing 132,000 green tones per year for 30 years are
presented in Table 5.
Table 5: Lifecycle costs of biomass feedstock
8 www.biocap.ca/images/pdfs/2005-04-30_Final_Report.pdf www.canbio.ca/upload/documents/sustainableforestsupplychainsoct192007.pdf www.dawsoncreek.ca/wordpress/wp-content/uploads/2011/10/Bio-EnergyPotentialinDawsonCreek-Final.pdf
(tonnes) Softwood Hardwood Total Biomass Cost/GTonne Cost/ODT*
Roadside Waste 152,344 283,773 436,116 45 100-115
Sawdust 162,500 - 162,500 40 90 - 104
Bark 50,781 - 50,781 40 90 - 104
Private Land 20,000 150,000 170,000 40 90 - 104
BC Timber Sales 652,416 140,000 792,416 40 90 - 104
Total 1,038,041 573,773 1,611,814
($/ODT) Low High Average
Roadside Waste 53 60 57
Sawdust 50 57 54
Bark 50 57 54
Dead Pinebeetle 52 120 86
Oil and Gas 75 90 83
Resource Year 1 30-year Average Total Cost
Annual Cost 5,256,000$ 7,691,754$ 230,752,608$
Escalation Rate (CPI) 2.5% 2.5%
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Long Term Supply Risk
The primary factors influencing the 30 year supply forecast are forest sector economics and the
annual allowable cut (AAC) within the region. Forecasting the future of BC’s forest sector and
the impact that would have on biomass feedstock supply over the next 30 years is challenging. A
decline in regional output would result in decreased availability of logging and mill residues.
With the decline of usable pinebeetle timber, it is expected that production in BC’s interior could
slow over the next decade. On the other hand, BC is rapidly expanding its market for wood
products internationally.
Overall, the future supply of mill and logging residues is uncertain and there has been a clear
trend in the increased utilization of residues from these operations for feedstock (energy and
pellets). For these reasons, available feedstock on private land and public land through BC
Timber Sales present the lowest risk supply in the region (Table 6). The Feedstock Availability
Study (Appendix A) estimates that private land and BCTS currently have 500% of the annual
biomass requirement for a 10 MW CGS plant.
Table 6: Supply risk for biomass feedstock sources
Source Supply Risk Comments
Roadside Waste (Slash) High
Supply is linked to forest sector economics Tenure issues can limit access to logging residues
due to liability concerns
Winter conditions present challenges for collection
Sawdust High
Supply is linked to forest sector economics
Competing demand for pellets, bio-energy, and pulp is increasing supply cost from mills
Bark Med
Supply is linked to forest sector economics Competing demand limited to bio-energy due to
high ash content
Private Land (standing timber)
Low (Med in Winter)
Supply is greater when forest industry is slower
Competition from mills is limited near Tomslake due to distance from mills
Winter conditions can present disruptions in supply
BC Timber Sales (standing timber)
Low (Med in Winter)
Supply is greater when forest industry is slower Competition from mills is limited near Tomslake
due to distance from mills
BC Government encourages small business sales in remote regions to promote economic activity
Winter conditions can present disruptions in supply
Physical Characteristics of Woody Debris
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Oven dried softwood and hardwood have a net calorific value of 21 GJ/tonne and 20 GJ/tonne
respectively. There is little variation in the energy density of dry white-wood, bark and branches
(Table 7).
Table 7: Net calorific value (GJ/tonne) of dried wood chips9
The moisture content of wood varies significantly based on whether the tree is alive or dead, the
season, and the site (Table 8). A live tree will have an average moisture content of 55%
compared to 20-25% for a standing dead tree. Studies have shown that a live tree cut in the
winter will lose 10 to 25% of its moisture content by the summer, and then regain 10-15 % of its
moisture content the following winter10
. Moisture content has a significant impact on the net
calorific value and bulk density (Table 8 & 9). Dead dry wood in the summer will have roughly
twice the energy content as the equivalent weight of green wood.
Table 8: Moisture content in relation to net calorific value (GJ/tonne)11
Table 9: Moisture content in relation to net calorific value (GJ/tonne)
9 FPInnovations: http://www.leafsolutions.ca/northernbioenergyconference.ca/images/Tony%20Sauder-Yukon.pdf
10
http://www.metla.fi/silvafennica/full/sf44/sf443427.pdf
11
Table 8 and 9 adapted from the “Calorific Value versus Moisture Content V17” spreadsheet model developed by
www.biomassenergycentre.org.uk
Species Stem Tree-Top Bark Foliage Branches Mean
Black Spruce (Sb) 18.8 21.6 19.5 20.9 20.7 20.1
Jack Pine (Pj) 19.4 21.2 21.3 21.4 21.4 20.8
Trembling Aspen (At) 18.7 20.3 19.5 18.8 19.9 19.3
Moisture Content %
(Average)
Calorific Value
(GJ/tonne) Hardwood
Calorific Value
(GJ/tonne) Softwood
Bone Dry 0 20 21
Roadside Waste - Summer 20 16 17
Roadside Waste - Winter 35 13 14
Roadside Waste - Average 28 14 15
Green Stems 55 9 9
Sawdust 30 14 15
Bark 30 n/a 15
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Although moisture content does impact bulk density, the type of material (solid wood vs. chips
vs. uneven slash) is the primary concern for transportation costs (Table 10).
Table 10: Estimated truck requirement for various biomass sources12
Resource Moisture content Number of Trucks for 100 (wet) tonnes
Softwood (stems) 50% 5 logging trucks Dead pine wood 25% 5 logging trucks Sawmill dust 30% 2.6 B-Trains Wood chips 40% 2.4 B-Trains Roadside Waste 40% 4.8 B-Trains
6.0 Summary and Recommendations
Results from the Feedstock Availability Study (Appendix A) indicate there is an adequate supply
of biomass in the region to support a 10 WM CGS plant. Long term supply risks are higher for
logging and mill residues. Due to the site location, BCTS and private land have the largest
available quantity of secure feedstock.
The average delivered cost for chipped biomass is $40-45 per green tonne and $90-115 per ODT.
These costs are averages and further work is needed to determine a spectrum of costs within the
region. This will allow for a marginal cost approach to supplying the estimated 132 000 green
tonnes per year for the CGS plant.
Recommendation #1: Contact biomass feedstock supply sources to get firm quotes on supply.
Recommendation #2: Delineate the delivered cost of biomass feedstock for each category in
order to create a supply curve for each. Split out the delivered cost by vendor cost, collection,
field processing, transportation, and site processing.
12
http://www.for.gov.bc.ca/pab/nfw/bioenergy-guide-2010.pdf
Moisture Content %
(Average)
Bulk Density
(tonnes/M3) Hardwood
Bulk Density
(tonnes/M3) Softwood
Stacked Stems - Bone Dry 0 0.39 0.29
Stacked Stems - Dead 25 0.45 0.33
Stacked Stems - Green 55 0.75 0.56
Chips - Bone Dry 0 0.25 0.16
Chips - Summer 25 0.25 0.18
Chips - Winter 35 0.31 0.23
Unchipped Slash - Bone Dry 0 0.12 0.08
Unchipped Slash - Summer 25 0.12 0.09
Unchipped Slash - Winter 35 0.16 0.12
Sawdust 30 n/a 0.17
Bark 30 n/a 0.17
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Further analysis is also needed on the potential feedstock supply from oil and gas. The 2008
biomass availability study for Dawson Creek indicated that the supply cost from oil and gas
would be relatively high. However, the gas industry is expanding rapidly in BC. Other sources
of feedstock were not considered in the study.
Recommendation #3: Contact oil and gas companies to get firm quotes on supply.
The net calorific value of wood is primarily driven by moisture content. Targeting relatively dry
feedstock will reduce the delivered cost of energy.
Recommendation #4: Base all feedstock contracts on the delivered energy content or dry basis
for wood to ensure that the proper incentives are in place.
The moisture content of feedstock in the region will vary from 20% to 55% depending on the
source and season. It would be reasonable to conclude that a minimum average moisture content
of 30% could be achieved through selective sourcing and blending of feedstock when needed.
The bulk density of woody debris is most affected by material composition and airspace (ie
mixed roadside waste versus chipped roadside waste). Field processing (shipping or bundling) is
an important consideration for reducing transportation costs.
Recommendation #5: Consider plant performance when refining the supply costs to account for
the impact of moisture content.
Recommendation #6: Assess alternative options for feedstock in the region that could include
tipping fees to offset the overall supply cost.
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7.0 Appendices
- Biomass Feedstock Availability Study Attached
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