The document discusses four thermochemical pathways for converting biomass to renewable fuels and bioproducts: (1) gasification followed by catalytic synthesis of alcohols and hydrocarbons, (2) fast pyrolysis producing bio-oil and char, (3) syngas fermentation using microbes to produce alcohols and acids, and (4) fermenting sugars extracted from bio-oil. Each approach is outlined along with its advantages and disadvantages compared to biochemical and other thermochemical methods. Research teams at Iowa State University are working to develop these thermochemical biorefinery technologies.

1. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Thermochemical Pathways to
Renewable Fuels and More
Robert C. Brown
Center for Sustainable Environmental Technologies
Iowa State University
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2. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Gasification Biorefinery
• Fibrous or mixed feedstock heated in
absence of oxygen to yield mixture of CO
and H2 (syngas) and char byproduct
• Gas clean-up followed by high pressure
catalytic synthesis to products
– Alcohols
– Hydrocarbons
CO2
Biomass Syngas
Gasifier Gas Cleaning Catalytic Reactor
Biobased
Heat fuels and
Air chemicals
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3. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Gasification Biorefinery
• Advantages (compared to
biochemical platform)
– Tolerates relatively dirty biomass
feedstock
– Produces uniform intermediate product
(syngas)
– Proven method for “cracking the
lignocellulosic nut”
– Allows energy integration in biorefinery
• Disadvantages (compared to
biochemical platform)
– Gas cleaning technologies still under
development
– Synfuel processing occurs at high
pressures Gasifier on the ISU Campus
– Capital costs thought to be higher
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4. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Thermochemical Synfuels Have Yield Advantage
Source: Röj, A.*, Automotive Fuels from Biomass – What is the best road forward, First International Biorefinery
Workshop, Washington, D.C., July 20-21, 2005, http://www.biorefineryworkshop.com/presentations/Roj.pdf
* Volvo Technology Corporation, anders.roj@volvo.com
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5. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Gasification Biorefinery Team
R. C. Brown F. Battaglia R. Fox T. Heindel
Mech. Eng. Mech. Eng. Chem. & Bio. Eng. Mech. Eng.
Gasification CFD CFD Fluid Dynamics
Photo
G. Kraus V. Lin J. Satrio D. Vigil
Chemistry Chemistry Chem. & Bio. Eng. Chem. & Bio. Eng.
Catalysis Catalysis Reaction Eng. Reaction Eng.
Photo Photo
Biomass CO2
Syngas
Gasifier Gas Cleaning Catalytic Reactor
Biobased fuels
Air Heat and chemicals
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6. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Fast Pyrolysis Biorefinery
• Directly converts biomass into liquid bio-oil (lignin, carbohydrate derivatives, and
water) and char
• Bio-oil used as boiler fuel, synthetic diesel fuel, or a variety of biobased products
• Char used for carbon sequestration and soil amendment
Synthetic
fuels
Bio-oil vapor
Cyclone
Hydrocracker
Steam Hydrogen
Bio-Oil
Char Reformer
Recover
Carbohydrate derived
Pyrolyzer
Phase aqueous phase
Fibrous
Separation
biomass
Boiler
Fuel Lignin Biobased products:
Asphalt binder
Soil stabilization agent
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7. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Fast Pyrolysis Biorefinery
• Advantages (compared to
biochemical platform)
– Opportunity for distributed
preprocessing (densifies biomass)
– Separates and uses both carbohydrate
and lignin
– Integrates into existing petroleum
refineries
• Disadvantages (compared to
biochemical platform)
– Bio-oil can be unstable, corrosive
Pyrolyzer at BECON facility
– Technology less developed
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8. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Fast Pyrolysis Biorefinery Team
R. C. Brown B. Shanks J. Satrio T. Meyer C. Williams H. Ceylan
Mech. Eng. Chem. & Bio. Eng. Chem. & Bio. Eng. Mech. Eng. Civ. Con. Env. Eng. Civ. Con. Env. Eng.
Pyrolysis Catalysis Reaction Eng. Combustion Lignin Utiliz. Lignin Utiliz.
Photo Photo
Bio-oil vapor Synthetic
R. Killorn
Cyclone fuels
Agronomy
Hydrocracker
Agri-char
Steam Hydrogen
Bio-Oil
Char Reformer
Recover
Carbohydrate derived
Pyrolyzer
Phase aqueous phase
Fibrous
Separation
biomass
Boiler
Fuel Lignin Biobased products:
Asphalt binder
Soil stabilization agent
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9. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Syngas Fermentation Biorefinery
• Biomass gasified to CO, CO2 and H2
• Autotrophic organisms ferment CO or CO2
and H2 into metabolic products
– Alcohols, carboxylic acids, esters
CO2
Biomass Syngas
Biobased fuels
Gasifier Gas Cleaning and chemicals
Bioreactor
Air
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10. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Syngas Fermentation Biorefinery
• Advantages (compared to
gasification biorefinery)
– Biocatalysts tolerant to sulfur and
chlorine contaminants
– Flexibility in the pressures and
CO/H2 ratios employed
– High selectivity in products
produced
– Genetic engineering can expand
portfolio of products
• Disadvantages (compared to
gasification biorefinery)
– Low rates of gas-liquid exchange
– Less developed technology
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11. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Syngas Fermentation Biorefinery Team
R. C. Brown B. Shanks T. Heindel
Mech. Eng. Chem. & Bio. Eng. Mech. Eng.
Gasification Mass Transfer Mass Transfer
Photo
A. Dispirito A. Pometto T. Bobik B. Nikolau
Microbiology Food Science Biochemistry Biochemistry
Fermentation Fermentation Genetic Trans. Genetic Trans.
Biomass Syngas
Biobased fuels
Gasifier Gas Cleaning
and chemicals
Air
Bioreactor
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12. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Bio-Oil Fermentation Biorefinery
Fiber Distillation
Ethanol
Pentose
Hot water
extraction
Fermenter
Water
Fiber byproduct
Cyclone Bio-oil vapor
Bio-Oil
Char Detoxification
Recovery
Fermenter
Pyrolyzer
Phase
Separation
Anhydrosugar & other
carbohydrate
Lignin
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13. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Bio-Oil Fermentation Biorefinery
• Advantages (compared to
biochemical)
– Opportunity for distributed
preprocessing
– Avoids enzymatic hydrolysis bottleneck
• Advantages (compared to
thermochemical)
– Avoids high pressure operations
– Opportunities for biotechnology
advances (such as direct fermentation
of anhydrosugar)
• Disadvantages
– Bio-oil is complex mixture of compounds
– Technology not well developed
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14. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Bio-Oil Fermentation Biorefinery Team
R. C. Brown M. Rover A. Pometto J. Satrio
Mech. Eng. Chemistry Food Science Chem. & Bio. Eng.
Pyrolysis Analysis Fermentation Reaction Eng.
Photo
Fiber
Distillation
Pentose and alkali
Hot water
extraction
Ethanol
Bio-oil vapor
Fermenter
Fiber byproduct
Cyclone Bio-Oil Detoxification
Recovery
Char Phase
Pyrolyzer
Separation Anhydrosugar &
other carbohydrate
Fermenter Water
Lignin
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15. ConocoPhillips Campus Visit
Bioeconomy Initiative October 25, 2006
Summary
• Several thermochemical options are under
development:
– Gasification to ethanol and F-T diesel
– Fast pyrolysis to boiler fuel, green diesel, and
biobased products and for carbon sequestration
– Syngas fermentation to biofuels and biopolymers
– Bio-oil fermentation to ethanol and biobased products
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