Wood Pellets for BioPower in the US and in the EU Anthony Baldridge, Tina Dreaden, Matyas Kosa, Kathy Woody, Christina Young Art J.

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1 Wood Pellets for BioPower in the US and in the EU Anthony Baldridge, Tina Dreaden, Matyas Kosa, Kathy Woody, Christina Young Art J. Ragauskas Georgia Institute of Technology Department of Chemistry and Biochemistry

2 Outline What is BioPower? Effect on Climate Change Forces that accelerate BioPower research Wood pellets Production facilities Markets for wood pellets Chemical composition Prospects Ragauskas, A. J. et al. (2006) Science 311,

3 Biopower Renewable biomass energy/ electricity Biomass can be virgin or waste Forests Cultivated land Sewage Agricultural crop & forestry residues Petrou, E. C. and Pappis, C. P. (2009) Energy and Fuels 23,

4 Why biopower? Considerations: worldwide energy demand expected to grow by > 50% by 2025 rising oil prices global climate change economic downturn in U.S. Biopower from biofuels: Decrease greenhouse gas emissions (CO 2 & CH 4 ) Shift dependence away from foreign petroleum Economic capital Ragauskas, A. J. et al. (2006) Science 311, Koh, L. P. and Ghazoul, J. (2008) Biological Conservation 141,

5 Biopower applications Electricity production Gas & coal fired power plants Residential space heating Pellet burning fireplaces Transportation fuels Personal & mass transportation Junginger, M. et al. (2008) Biomass and Bioenergy 32,

6 Biopower Cycle Image taken from: 6

7 Environmental Impacts of Cycle Greenhouse gas emissions are of great concern. Finding ways to decrease amount of emitted CO 2, CH 4, and other gases is needed. Biopower addresses these by: Using sources that can produce a carbon neutral system/cycle Use of animal waste can reduce pollution and methane emission Biomass (wood) use prevents wildfires which: Globally are 40% of gross global CO 2 emissions Allows for controlled combustion uses (180%) more efficient Motivates forest understory gathering of wood material 7

8 Power Choices and Climate Change By adapting current methods emitted CO 2 and other greenhouse gases could greatly diminish. Currently, wood pellets are gaining use in co firing plants that use coal. Biopower production is rising in the United States and Europe. Substitution of fossil fuel with biomass/ biopower decreases net emissions by 750% (note figure). Image taken from: 8

9 Categories of biofuels Solid biofuels Pellets, sewage, wood Liquid biofuels Biodiesel (i.e., long-chain fatty acids), bioethanol, biobutanol, green diesel ethanol methyl-palmitate Gaseous biofuels Thermal or microbial degradation of biomass used to form biogas, i.e. CH 4 or H 2 Petrou, E. C. and Pappis, C. P. (2009) Energy and Fuels 23,

10 Pertinent research Plant biochemistry & genetics increased yield, resistance, sustainability Biorefineries: conversion & fractionation of raw materials (polysaccharides & lignin) to products Direct energy, transportation fuels, chemical products (solvents, plastics, fragrances) Production of biofuels Cost reduction & efficiency Ragauskas, A. J. et al. (2006) Science 311,

11 Biopower support Global: International Energy Agency (IEA) Bioenergy Task 40 (2003) Develop bioenergy trade to secure supply & demand in a sustainable way National: Obama s Economic Stimulus (2009) $54 billion towards green energy (research, tax cuts, etc.) Local: Georgia Power will convert coal-fired power plant to burn wood chips (2009) One of largest biomass power plant in U.S. Junginger, M. et al. (2008) Biomass and Bioenergy 32, Department of Energy, 11

12 What are Wood Pellets? Made from wood waste (e.g. sawdust and wood chips) Densified wood particles: less then 10% moisture Cylindrical Diameter: 6 12 mm Length: 5 30 mm 12

13 Applications of Wood Pellets Household use Central heating boilers: Heat transferred to water heater and heat distribution system for entire home Stoves: Provide heating and cooking for a single room Combined Heat and Power (CHP) Plants Woody biomass-fueled power plants Co-firing wood pellets and coal: wood pellets partially substitute for coal, decreasing net CO 2 and SO 2 emissions with respect to burning straight coal. Fiedler, F. Renewable and Sustainable Energy Reviews 2004, 8, 201. Hartmann, D.; et al. Biomass and Bioenergy 1999, 16,

14 Production process overview milling drying Raw wood waste (pellet-press or die) Pelletisation Wood pellets Holm, J. K.; et al. Energy & Fuels 2006, 20,

15 Pellet Production Pelletisation (Compression of Pellets) Raw Material Drying and Processing Cooling Pellet Transport/ Storage After the raw material is dried, it is extruded through cylindrical channels. The friction between the raw material and the press results in compression of the wood into pellets. Wang, C.; Yan, J. International Journal of Green Energy 2005, 2,

16 Compression of Wood Pellets Vs. Compressing pellets requires energy so why make densified wood pellets? Dense particles give longer burn times and higher energy efficiency Lower transportation costs Increases storage capacity Obernberger, I. et al. Biomass and Bioenergy, 2004, 27, 653; Holm, J. K. et al. Energy & Fuels 2006, 20,

17 Current Production Plants in the Southeast Image taken from: 17

18 Current Production Plants in Europe Image taken from: 18

19 Market for wood pellets Depends on: Availability (cost of transport) Heating-value/cost ratio compared to other fuels Possible consumers: Energy suppliers Commercial/Industrial Residential Creating demand for equipment used in production and consumption of pellets 19

20 Heating Value vs. Cost in the US Pellet Fuels Institute 20

21 Energy Suppliers Biomass is the only truly carbon neutral energy DOE: 45x10 9 kwh/y from biomass in US 1 MWh of biomass power -> 1.6 t of CO 2 emission is avoided, hence substituting new carbon release with recycling CO 2 => reduction of 30x10 6 t/y Oglethorpe as an example: Building: 3, 100 MW biomass electric generating plants by 2015 Fuel: process round wood, primary manufacturing residue, harvest residue x10 6 $/facility with 40 jobs in each NRECA, Green Power, Ag Energy Working: 25% of energy from renewable locally grown sources Department of Energy (DOE) USA Biomass Oglethorpe Power National Rural Electric Cooperative Association Green Power EMC Ag Energy Working Group 21

22 Other Markets Commercial/Industrial: Examples: Theater (Elma, WA), manufacturing facility (Claremont, NH), farm (Sutton, Quebec), prison (Walla Walla, WA) Residential: Equipment: Over 1 million homes using pellet stoves in the US, in 2008 ( For pelletizing: mills, grinders, dryers, pelletizing, packaging For consumers: silos, stoves, boilers 22

23 General Chemical Properties of Pellets high density ensures high heating value and steady combustion behavior lower water content -> better heating value lower ash content -> avoid slag binding agent, preferably natural like corn or maize starch to improve pellet formation avoid chemical glues which contribute to pollution F. Fiedler, The State of the Art of Small Scale Pellet-Based Heating Systems and Relevant Regulations in Sweden, Austria, and Germany. 23

24 Fuel Properties as a Function of Chemical Constituents Ideally, wood pellets should contain chemically untreated material that is free of additives However, sometimes this is not the case what results in pollutant emissions, deposit formations, and corrosion issues Emission - increased contents of N, Cl, and S as well as heavy metals Corrosion - increased heavy metals and Cl contaminate ash Deposit formation - increased K - negative effect on ash melting and contributes to higher aerosol formation I. Obernberger, G. Thek, Physical Characterization and Chemical Composition of Densified Biomass Fuels with Regard to their Combustion Behavior, Proceedings of 1st World Conference on Pellets, Sept. 2002, Stockholm, Sweden, ISBN , pg

25 Chemical Composition of Wood Pellets (General Analysis) parameter unit average standard minimum maximum value deviation diameter D mm length mm bulk density kg/m particle density kg/dm water content wt.% (w.b.) ash content wt.% (d.b.) GCV MJ/kg (d.b.) NCV MJ/kg (d.b.) C wt.% (d.b.) H wt.% (d.b.) N wt.% (d.b.) S mg/kg (d.b.) , Cl mg/kg (d.b.) K mg/kg (d.b.) , abrasion wt.% (w.b.) starch content wt.% (d.b.) Cd mg/kg (d.b.) Pb mg/kg (d.b.) Zn mg/kg (d.b.) Cr mg/kg (d.b.) Cu mg/kg (d.b.) densified biofuels were studied (60%) were wood pellets collected from 30 different producers located in Austria, Spain, Sweden, Italy, Czech Republic, and Norway Table/data adapted from: I. Obernberger, G. Thek, Physical Characterization and Chemical Composition of Densified Biomass Fuels with Regard to their Combustion Behavior, Proceedings of 1st World Conference on Pellets, Sept. 2002, Stockholm, Sweden, ISBN , pg

26 Example: Wood Pellets, Sweden Run Moisture Content (%) Fresh pine fraction (%) Stored pine fraction (%) Spurce fraction (%) S S S S S S S S S S S S Fuel pellets production in Sweden is mainly from sawdust and planar shavings of Scots pine and Norway spruce Pellets were analyzed for moisture and composition M. Arshadi, R. Gref, P. Geladi, S.-A., Dahlqvist, T. Lestander, The Influence of Raw Material Characteristics on the Industrial Pelletizing Process and Pellet Quality, Fuel Processing Technology, 89 (2008),

27 Pellet Standards Ensure Quality Pellet standard Sweden - SS Austria Germany Parameter Unit Class 1 Class 2 Class 3 O-Norm DIN DIN plus M7135 Diameter (d) mm Length mm 4 x d 5 x d 6 x d 5 x d 50 5 x d Density kg/dm Water content % Abrasion/small particles % Ash content % < Upper caloric value MJ/kg Sulphur content % weight Nitrogen content % weight Chlor content % weight Additives % Table 4: Pellet standards in Sweden, Austria and Germany 1 bulk density 2 particle in weight % <3mm 3 amount must be specified 4 type and amount must be specified F. Fiedler, The State of the Art of Small Scale Pellet-Based Heating Systems and Relevant Regulations in Swedent, Austria, and Germany. 27

28 Future of BioPower in the US *only corn stover and cereal straw Chart showing predicted BioPower usage, including wood pellets versus the predicted cost of logistics for biomass, including: harvest & collection, preprocessing, storage & queuing, transportation & handling Table shows the predicted growth in biomass production, including: corn stover, switchgrass, cereal straw and woody biomass DOE, Biomass: Multiyear Program Plan, May 2009 DOE, Vision for Bioenergy and Biobased Products in the US,

29 Future of BioPower in the EU 2005: 41 TWh/y of electricity from solid biomass and 13 from biowaste 20% of all energy consumption must come from renewable sources by 2020, according to the Renewable Energy Roadmap, as accepted and published by the Commission of the European Communities. Their goal of reaching 12% until 2012 most likely won t be met however. Reduce annual fossil fuel consumption by 250 Mtoe annually Mt decrease in CO 2 emission, saving of billion euro Communication: Renewable Energy Road Map, Brussels,

30 Main references Petrou, E. C. and Pappis, C. P. (2009) Energy and Fuels 23, Ragauskas, A. J. et al. (2006) Science 311, Koh, L. P. and Ghazoul, J. (2008) Biological Conservation 141, Junginger, M. et al. (2008) Biomass and Bioenergy 32, Bain, Richard L; Overend, Ralph P. Forest Products Journal. 2002, 52, 2, Fiedler, F. Renewable and Sustainable Energy Reviews 2004, 8, 201 Hartmann, D.; et al. Biomass and Bioenergy 1999, 16, 397 Holm, J. K.; et al. Energy & Fuels 2006, 20, Wang, C.; Yan, J. International Journal of Green Energy 2005, 2, Obernberger, I. et al. Biomass and Bioenergy, 2004, 27, 653 I. Obernberger, G. Thek, Physical Characterization and Chemical Composition of Densified Biomass Fuels with Regard to their Combustion Behavior, Proceedings of 1st World Conference on Pellets, Sept. 2002, Stockholm, Sweden, ISBN , pg M. Arshadi, R. Gref, P. Geladi, S.-A., Dahlqvist, T. Lestander, The Influence of Raw Material Characteristics on the Industrial Pelletizing Process and Pellet Quality, Fuel Processing Technology, 89 (2008),