woody debris characterization study - fpinnovations...

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

Woody Debris Characterization Study

Reed Environmental Inc. 2

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



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



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

http://atlas.nrcan.gc.ca/auth/english/maps/environment/forest/useforest/sawmills

http://www.for.gov.bc.ca/hts/tsa/tsa41/

http://www.for.gov.bc.ca/hts/tfl/tfl48/tsr3/48tf07ra.pdf



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.



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

http://www.pw.utc.com/media_center/press_releases/2012/05_may/05-02-2012_00002.asp



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

12

14

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18

20

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

http://www.biomassinnovation.ca/pdf/BradSutherlandHeavyCons.pdf



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



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



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%

http://www.biocap.ca/images/pdfs/2005-04-30_Final_Report.pdf



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



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

http://www.leafsolutions.ca/northernbioenergyconference.ca/images/Tony%20Sauder-Yukon.pdf

http://www.metla.fi/silvafennica/full/sf44/sf443427.pdf

http://www.biomassenergycentre.org.uk/



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

http://www.for.gov.bc.ca/pab/nfw/bioenergy-guide-2010.pdf



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.



7.0 Appendices

- Biomass Feedstock Availability Study Attached

woody debris characterization study - fpinnovations...

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