1. Let’s envision an ideal biofuel process

2. Feedstock CO 2

3. Biomass ä ä Biomass ä ä Plants ä ä Animals (by way of plants) ä ä Plants ä ä Use solar energy to convert water and CO 2 to sugars through the process of photosynthesis ä ä Harvested portions of live plants or remains are sources of biomass ä ä Animals ä ä Consume plants (or consumers of plants) ä ä Elimination products or remains are sources of biomass ä ä Virtually all of our current energy supply is derived from biomass (fossil fuels are just “well-aged”)

4. Multiple Feedstocks treestrees grassgrass agricultural residuesagricultural residues energy cropsenergy crops municipal solid waste municipal solid waste sewage sludge sewage sludge animal manure animal manure

5. 78 10.9 3 4.3 400 330 220 U.S. Biodegradable Wastes Municipal Solid Waste Sewage Sludge Industrial Biosludge Recycled Paper Fines Agricultural Residues Forestry Residues Manure Amount (million tonne/year) Alcohol Potential Waste (billion gal/year) 101.40.4 0.5 52 43 28 Total 1,046 135 U.S. Gasoline Consumption = 130 billion gal/year U.S. Diesel Consumption = 40 billion gal/year

6. How to Get Liquid Transportation Fuels from Biomass ä ä Convert sugars and starches to ethanol – fermentation ä ä Convert plant oils to biodiesel – transesterification ä ä Convert anything to liquid – pyrolysis ä ä Convert anything to gas (gasification) with subsequent conversion to liquid – aka biomass to liquids (BTL)

7. The Challenge Jet Fuelforestwastecornstover switch-grass Gasification to “syngas” (CO + H 2 ) Diesel Gasoline Lignocellulose Fisher-Tropsch methanol Gasoline corngrain sugarcane starch Saccharification ligninburn Enzymatic Fermentation Ethanol Pyrolysis, fast or slow gases bio-oil sugar Sugar/starch Liquid Phase Processing Dissolution Can we achieve sufficiently high yields of targeted chemical compounds from solubilized biomass fractions to justify the cost of biomass pretreatment?

8. Biofuels, in Order of Maturity, p1 of 2 Adopted from NREL (2006) http://www.nrel.gov/biomass/pdfs/39436.pdf FUELSOURCEBENEFITSSTATUS Grain/Sugar Ethanol Corn, sorghum, sugarcane High-octane Widely available sources Commercially proven BiodieselVegetable and seed oils; fats and greases Increased fuel lubricity Widely available sources Commercially proven Gasoline and diesel blends Ethanol or biodiesel blended with petroleum fuels Relatively straightforward for refineries to process Decreased sulfur emissions over standard fuels Commercial trials in progress Cellulosic Ethanol Grasses, wood chips, and agricultural residues High-octane Less demand on agricultural lands than grain ethanol DOE program targeting 2012 demonstration ButanolCorn, sorghum, wheat, sugarcane Low-volatility High energy-density Water tolerant BP and DuPont in progress

9. Biofuels, in Order of Maturity, p2 of 2 FUELSOURCEBENEFITSSTATUS Pyrolysis Liquids Lignocellulosic biomass Can utilize waste products Potential source of aromatics and phenols Several commercial facilities produce energy and chemicals Syngas LiquidsVarious biomasses Can utilize waste products Can be integrated with fossil fuel sources (e.g., coal) High quality fuel Commercially demonstrated a large scale using fossil fuels; biomass projects underway Biodiesel or jet fuel MicroalgaeHigh yield per acre Could be integrated with CO 2 capture and reuse Demonstrated at pilot scale in 1990s. Many start-ups currently underway Hydrocarbons (designer fuels) Biomass carbohydrates Generate synthetic copies of current petroleum derived feedstocks Laboratory-scale research Adopted from NREL (2006) http://www.nrel.gov/biomass/pdfs/39436.pdf

10. Ethanol (EtOH) ä ä Chemical Composition ä ä CH 3 CH 2 OH or (C 2 H 6 O) ä ä Ethanol is ethanol – source independent ä ä Also known as ethyl alcohol or grain alcohol ä ä 2 types: ä ä Biologic: conversion of starches to sugar followed by fermentation of sugar with yeast ä ä Synthetic: acid catalyzed hydration of ethylene ä ä Blending ä ä Currently used as a additive (10% max) to improve performance (octane) of gasoline ä ä Internal combustion engines must be designed to accommodate ethanol content >10% OH

11. Ethanol Sources ä ä Most common sources are plants with high sugar or starch content (e.g., corn, beets, cane, potatoes) ä ä Sources with more complex cellular structures (e.g., wood, grass, stalks) require more effort to extract available sugars (cellulosic ethanol)

12. Biodiesel or FAME (Fatty Acid Methyl Ester) ä ä Chemical composition ä ä Similar to petroleum diesel fuel in structure (straight chain) and number of carbon atoms (10 to 20) ä ä Differs in that it is oxygenated and has a small number of double bonds ä ä Fuel characteristics will vary slightly depending upon source ä ä Blending ä ä Completely miscible with diesel fuel ä ä Used as an additive (5% max) to increase cetane and improve performance of diesel ä ä Internal combustion engines must be designed to accommodate fuels with FAME content >5%

13. Biodiesel Sources ä ä Plant oils ä ä Soybean ä ä Palm ä ä Rice ä ä Cottonseed ä ä Rapeseed (canola) ä ä Waste oils (plant and animal) ä ä Algae – recent interest because ä ä High amounts of oil ä ä Minimal competition with food crops and crop land ä ä Can be grown on land with low potential for CO 2 sequestration (e.g. deserts) ä ä Does not necessarily require fresh water

14. Biomass to Liquids (BTL) via Gasification ä ä Solid or solid/liquid biomass is converted to gas at high temperatures in the presence of small amounts of oxygen ä ä Main objective is to transfer the maximum amount of chemical energy within the feedstock to the gaseous fraction by producing a high yield of low molecular weight products (high H:C) ä ä The resulting gas is “conditioned” to produce synthesis gas (syngas) ä ä Syngas is then converted to liquid fuel via the Fischer-Tropsch process

15. High-Productivity Feedstocks Corn grain Sweet sorghum Energy cane 3.4 20 30 Productivity Dry tons/(acre·yr)

16. Sweet Sorghum Grows in ~35 US states

17. Energy Cane

19. High Agricultural Income Corn grain Sweet sorghum Energy cane ($2.40/bu) ($40/tonne) ($40/tonne) 340 730 1090 Gross Income $/(acre·yr)

20. Low Environmental Impact Water Fertilizer Pesticides Herbicides Soil erosion Corn Sweet Energy Grain Sorghum Cane High Low Low Environmental cost per unit of biomass

21. Ideal Process Properties No sterility No genetically modified organisms (GMOs) Adaptable No pure cultures Low capital No enzymes High product yields No vitamin addition Co-products not required

22. Fuel Properties Ethanol MTBE Mixed Alcohols Octane high high high Volatility high low low Pipeline shipping no yes yes Energy content low high high Heat of vaporization high low low Ground water damage no yes no

23. MixAlco Process Ferment Dewater Pretreat ThermalConversion Hydrogenate Lime Kiln MixedAlcoholFuels MixedKetones Biomass Hydrogen Calcium Carbonate Lime Carboxylate Salts

24. Storage + Pretreatment + Fermentation Biomass + Lime + Calcium Carbonate Gravel Air Tarp Cover

25. Dewatering Ferment Dewater Pretreat ThermalConversion Hydrogenate Lime Kiln MixedAlcoholFuels MixedKetones Biomass Hydrogen Calcium Carbonate Lime Carboxylate Salts

26. Vapor-Compression Dewatering Salt Solution (Fermentor Broth) Distilled Water Filter Salt Crystals Compressor Work

28. Effect of Feedstock Cost (800 tonne/h, 15% ROI) -40 -20 0 20 40 Biomass Cost ($/tonne) 1.00 0.80 0.60 0.40 0.20 0.00 Alcohol Selling Price ($/gal)

29. Centralized Processing 15.3 mi 50% of area planted

30. How do we increase engine efficiency? Electric hybrids (2 X ) Electric hybrids (2 X ) Better engines (2– 4 X ) Better engines (2– 4 X )

31. Meeting US gasoline needs by growing energy cane in Brazil 1 × 2 × 3 ×

32. Meeting US gasoline needs by growing sweet sorghum in United States 1×1× 2×2× 3×3×

33. Conclusion Reduce wastes Reduce wastes Cleaner air Cleaner air New agricultural markets New agricultural markets Energy security Energy security Improve balance of payments Improve balance of payments Address global warming Address global warming Address energy shortage Address energy shortage More flexible international relations More flexible international relations Benefit developing nations Benefit developing nations