Beneficiation of Chipped and Ground Woody Biomass

Jim Dooley

This presentation is based upon research and development that was supported in-part by the U.S. Department of Agriculture – NIFA - Small Business Innovation

Research Program Contract No. 2009-33610-01114

Cleaning “dirty” biomass to produce quality feedstocks

Agenda• Forest Concepts – Supply Chain R&D• Characterization of Low-Grade Woody Biomass• Pathways to Achieve User Specifications• Results and Discussion• Final Thoughts

Who we are Started in 1995 to create new uses for roundwood• ELWd® engineered large woody debris habitat (1998)• FlowCheck™ engineered log erosion barriers (2000)

– USFS R4, Boise NF

• Transportable Roundwood Processing System (2002)– National Fire Plan, USFS R6, Mason Conservation District

• WoodStraw ® erosion control material (2005)– USDA/NIFA, USFS-RMRS, BLM

• Woody Biomass and Brush Baler (2008)– Street legal baler to replace small chippers

• Beneficiation of Chipped and Shredded Woody Biomass• Precision Cellulosic Biofuel Feedstocks (DOE funded)

Biomass Supply Chain & Forest Concepts

CollectionAggregationBale Transport Storage Pre-processing Conversion

Energy and

Payload

Beneficiation

Pre-Processing

Low Energy Comminution

Precision Particles

Woody Biomass Baling

Hog Fuel

Managed Drying and

Bale Handling

Bale Optimized for Horizontal

Grinders

Managed Drying and

Bale Handling

Biomass Feedstock Quality Matters

• Ash content is a major issue for pellet fuel feedstocks• Soluble minerals (e.g. alkanes, iron oxide, calcium

carbonate, sodium, potassium, …) greatly reduce yield of biofuels due to catalytic reactions

• Particle shape, size, and surface-to-volume ratios affect reaction kinetics, drying rates, materials handling, …

• Quality and value can be improved by:– Anatomical fractionation (bark, leaves, …)– Cleaning to remove soil, gravel, metal, grit, …– Washing to reduce extractives– Size sorting– Comminution methods and equipment

Biomass Feedstock

The problem with Hog Fuel• Dirt and grit• Bark• Fines• Overs

6/20/2012 7

Cumulative Material Composition

Bark11%

Leaves2%

Fines10%

Debris0%

Grit22%

Wood + (Wood Fraction)

6%

Clean Wood48%

WoodFiber54%

Wood + (Bark Fraction)

1%

Clean Wood

Wood + (Wood Fraction)Wood + (Bark Fraction)

Bark

Leaves

Fines

Debris

Grit

Distribution by Size & Class

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

1 1/2 1 1/2 #4 #8 #16 Pan

Sieve Size (Containing the Material)

% o

f Tot

al M

ass

Washable Grit

Debris

Fines

Leaves

Bark

W+

CW

Cumulative Catagorized Materials

100 million tons per year available

The OPPORTUNITY with Hog Fuel•• 50% wood50% wood•• Low costLow cost•• AbundantAbundant

6/20/2012 8

Cumulative Material Composition

Bark11%

Leaves2%

Fines10%

Debris0%

Grit22%

Wood + (Wood Fraction)

6%

Clean Wood48%

WoodFiber54%

Wood + (Bark Fraction)

1%

Clean Wood

Wood + (Wood Fraction)Wood + (Bark Fraction)

Bark

Leaves

Fines

Debris

Grit

Distribution by Size & Class

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

1 1/2 1 1/2 #4 #8 #16 Pan

Sieve Size (Containing the Material)

% o

f Tot

al M

ass

Washable Grit

Debris

Fines

Leaves

Bark

W+

CW

Cumulative Catagorized Materials50 million tons of wood fiberIF you can separate it from the rest

The problem with Urban Chips• Dirt and grit• Bark & Leaves• Fines

6/20/2012 9

30 million tons per year available

Northwest Tree Service Chipper Material Composition

Wood + (Bark Fraction)

3%

Bark11%

Leaves10%

Fines21%

Debris0%

Grit10%

WoodFiber45%

Wood + (Wood Fraction)

11%

Clean Wood34%

Clean Wood

Wood + (Wood Fraction)Wood + (Bark Fraction)

BarkLeaves

FinesDebrisGrit

Distribution by Size & Class

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

1 1/2 1 1/2 #4 #8 #16 Pan

Sieve Size (Containing the Material)

% o

f Tot

al M

ass

Washable Grit

Debris

Fines

Leaves

Bark

W+

CW

Northwest - Tree Service - Chipper

Woody Biomass BeneficiationUSDA SBIR Objective:

Increase the supply of wood fiber to reduce conflicts and competition for traditional mill residuals – This was 3 years before BCAP!

Develop technologies to reprocess hog fuel and urban chips into fractions suitable to replace traditional mill residuals– Reduce bark content to 1, 3, or 6 % targets– Deliver clean streams of wood and bark that meet

industry sector standards for ash and grit content

Allowable Ash by End Use

DOE Design Case – 1% Ash

Beneficiation Operations

• Screening – Overs, unders, fines, soil

• Mechanical Beating – Break up non-wood

– Wet or dry• Rinsing – sand, silt, clay, fine organic

• Air Separation - rocks

• Flotation Separation – rocks and clays

• Dewatering or drying• Specific gravity separation – gravel, sand

USDA-SBIR Validation System1-ton (od) per hour

Ash Content by Sieve Fraction for Land Clearing Woody Biomass

Sample: 2011.07.12.001

Sieve IDOpening (mm)

Ash Content

3 75.0 0.5%1 1/2 37.5 0.56%1 25.0 1.07%1/2 12.5 1.21%1/4 6.3 1.86%1/8 3.2 14.21%

No. 16 0.7 20.82%Pan 40.11%

Note: Clean wood is ~ 0.3% ash

Ash Content 12.3 %

Pile

Dry Flail

Floatation Tank

Initial Screen

66 % Wood13 % Bark21 % Other12.3 % Ash

80 % Wood13 % Bark7 % Other2.1 % Ash

Wet Flail

Final Screen

67 % Wood15 % Bark18 % Other1.4 % Ash

77 % Wood11 % Bark13 % Other1.1 % Ash 79% Wood

18 % Bark3 % Other0.6 % Ash

100%

67%

60%

61%

Mass

57% Note: This experiment sought to minimize ash while maximizing total biomass retained. Thus, the bark content was higher than we wanted. Removing more bark would substantially reduce the mass yield of clean biomass.

SBIR Beneficiation Validation Test Ground Land Clearing Debris - Seattle

Raw Material66 % Wood13 % Bark12.3 % Ash

After Wet Flail77 % Wood11 % Bark1.1 % Ash

Ground Land Clearing DebrisSample: 2011.07.12.001

SBIR Beneficiation Validation Test Urban Arborist Chips – Auburn, WA

Pile

Dry Flail

Floatation Tank

Initial Screen

26 % Wood22 % Bark52 % Other3.2 % Ash

48 % Wood20 % Bark32 % Other2.6 % Ash

Wet Flail

Final Screen

65 % Wood22 % Bark13 % Other2.6 % Ash

59 % Wood23 % Bark18 % Other2.4 % Ash

100%

43%

27%

34%

Mass

na Note: This experiment sought to minimize ash while maximizing total biomass retained. Thus, the bark content was higher than we wanted. Removing more bark would substantially reduce the mass yield of clean biomass.

Conclusions from Validation Tests

• Land Clearing Debris– Screening alone can often get the ash content below 3%– Dry or wet flail processing can further reduce ash to less than 1.5%– Bark content was not appreciably reduced – More work to be done!– Approx. 60% of mass could be redirected to fuel pellets or furnish

• Arborist Ponderosa Pine Chips– Screening and dry flail increased wood content from 26% to 65%– More than 65% of mass was removed by processing– Total ash remained approx. 2.5% throughout testing– This sample would be uneconomical to upgrade

Market Implications

• Reprocessing ground forest residuals and other woody biomass can contribute substantial new sources of fiber to select existing and new uses– Composite panel core stock– Densified solid biofuels (export pellets)– Advanced biofuel feedstocks– Polymer composite products

Final Thoughts

• Forest Concepts’ demonstration scale portable system is available for use – 1 bdt per hour

• Forest Concepts biomass lab is open!– Particle size and shape– Anatomical and debris content analysis– Ash content– Bulk density– Flowability

• Our technical team will consult with engineering providers, plant operators, and biomass suppliers to improve feedstocks

Thank You !Jim Dooley

Forest Concepts3320 West Valley Hwy. N. D110

Auburn, WA 98001

p.253.333.9663 / jdooley@forestconcepts.com / www.forestconcepts.com

Development was supported in-part by the NIFA Small Business Innovation Research program of the U.S. Department of Agriculture, grant numbers 2008-33610-18880 and 2009-33610-101114.