Ethanol

Solar Energy Photosynthesis Biomass Corn/Cane EthanolBioethanol Natural Vegetation (grass, foliage, timber) Energy cropsAg and Urban Wastes Crops Avg Max 6.7% of Incident Sunlight Converted to Biomass % 2,3,4 1 - Kheshgi et al Cook et al Lynd et al Wooley et al % 1

Cellulosic Sources Bioethanol defined as being derived from cellulose/hemicellulose Types of energy crops: –Hybrid Poplars –Cottonwoods –Willows –Switchgrass

Poplars

Poplar Plantation

Poplar Cutting

Switchgrass Stand

Switchgrass

Cellulosic Biomass Composition Cellulose 45% Hemicellulose 30% Lignin 15% Other 10% Herbaceous Energy Crops Cellulose 43% Hemicellulose 27% Lignin 17% Other 13% Agricultural Residues Municipal Solid Waste Ash 15% Lignin 10% Hemicellulose 9% Other carbohydrates 9% Protein 3% Other 9% Cellulose 45% Cellulose 45% Hemicellulose 25% Lignin 22% Extractives 5% Ash 3% Woody Crops

DOE approach Use of idle crop land (82 million acres) –392 million acres are suitable for biomass best land is in the north central region –Short-rotation woody crops expected annual yields of 5 or more dry tons per acre could be grown on 225 million acres (2423 million tons) –Herbaceous energy crops with similar yields could be grown on 324 million acres (1427 million tons) –It would take 82 million acres (6 dry tons/acre) to produce 492 million tons of dry biomass. This would yield to produce ~ 40 billion gallons of ethanol - enough to replace 22% of US gasoline consumption on an energy basis. –If you used all 392 million acres ~ 190 million gallons, slightly more than enough ethanol to replace gasoline consumption.

U.S. Crop Suitability Map Source: Oak Ridge National Laboratory

Source: ORNL County Level Study

Gasoline requirements per region (% of Total billion gallons) 27% 16% 14% 15% 8% 5% 3% 12%  5% > 5 to  10% > 10 to  20% > 20% Do to rounding values may not equal 100%

Land Use in the Contiguous 48 States Use Acreage (Million Acres) Proportion of Total Area (%) Grassland Pasture & Range Forest Cropland Special Use Other Use

Ethanol Supply & Demand Data from Urbanchik, 2000

Ethanol fuel properties in relation to fuel performance Energy density Heat of vaporization Lower flame temperature Relative volume of combustion products Octane Number Lower mpg Larger tank More air to cylinder Increased power Decreased cooling needs Higher efficiency in optimized engine Increases work from gas expansion Allows increased compression ratio and hence higher Power and efficiency Property Ethanol/Gasoline Value Impact From Lynd 1996;Bailey 1996

Corn MillingLiquefactionSaccharificationFermentation DistillationDehydration Centrifugation Evaporation Dry Feed Mixing Drying Cooling Corn  -Amylase Gluco-amylase Yeast Fuel Grade Ethanol Denaturant Distillers Dried Grains w/ soluble Dry Milling Simplified Process

Net Corn Costs Other Operating Costs Annualized Capital Costs Total Production Costs $/gal Dry Mill Wet Mill Current Ethanol Costs

How much land for corn ethanol? 2.5 gallons of ethanol from a bushel of corn US average corn yield per acre was 132 bushels for the period from 1997 to 1999 Thus, a little under 3.9 million acres of corn is needed to meet the current ethanol demand 9.6 million acres would be needed to meet the 2004 ethanol demand

Issues The projected 2004 demand is essentially equivalent to the ethanol produced from cane sugar in Brazil (3.1 vs 3.4 billion gallons). Infrastructure development - mainly dry mills Co-products Energy Balance

Energy Requirements Units of Fossil Energy/Unit of Fuel Energy –Gasoline1.29 –Diesel1.19 –Corn ethanol0.99 Sources: Sheehan [1998], Riley [1995], Shapouri [1995]

Reasons to use Bioethanol Energy security Petroleum prices rise CAFE Increase Serious about greenhouse gas emissions

Size Reduction Dilute Acid Pretreatment Liquid Solid Separation Detoxification Via Ion Exchange Enzyme ProductionSSCF Fermentation Separation Solids Processing Cogen Biomass Fuel Grade Ethanol Simplified Bioethanol Process

Energy Requirements Units of Fossil Energy/Unit of Fuel Energy –Gasoline1.29 –Diesel1.19 –Corn ethanol0.99 –E95 (lignocell)0.25 Sources: Sheehan [1998], Riley [1995], Shapouri [1995]

Current Ethanol Costs Net Feedstock Costs Other Operating Costs Annualized Capital Costs Total Production Costs $/gal Dry MillWet Mill Cellulosic

Effect of Biomass Cost on Ethanol Production Cost

$ 1.00/gal ethanol $ 1.20/gal ethanol E85 Costs vs Gasoline Costs Gasoline Cost Volume Basis Energy Basis Dedicated E85 Vehicle Blended Fuels Costs ($/gal) Gasoline Costs ($/gal) $1.14 $0.94 $1.72 $1.42 $1.53 $1.26

Fuel Economics Cellulosic ethanol currently costs too much Gasoline$/gal $/liter Refinery gate price: Transportation, storage, retailing: Taxes: Total (price at pump) Ethanol Production cost: Assume distribution $/gal as above Hold total tax revenue constant Total Total ($/volume gasoline equivalent)

Fuel/Vehicle Issues for Transition E10: current gasoline ICE are able to use up to E10 High level blends (up to E85): Flexible fueled ICE –2 million current vehicles in U.S. –Requires vehicle modifications –Dedicated vehicles slightly more efficient Start by all vehicles using E10 (50 billion liters for U.S., 10 X present production) Manufacture flexible fueled vehicles, gradually shifting to dedicated vehicles as ethanol production increases

For lignocellulosic ethanol to penetrate transportation fuel market: Technological advances & cost reductions Infrastructure development Higher petroleum prices Stringent GHG emissions legislation Subsidize production (via lower taxes) Consumer demand for renewable fuels Consumer acceptance of land use

Global Warming Potential for Alternative Fuel Vehicle Options Ethanol Options Lave 2000

Environmental Impact food vs. energy land use competition soil quality water quality chemical inputs biodiversity –monoculture –suitability for wildlife habitat –landscape effects –stability

Could the U.S. produce sufficient ethanol from energy crops to fuel its light-duty fleet? To replace the 130 billion gallons (490 billion liters) of gasoline, would require million acres (approx. ¼ of land area lower 48 states) Investment in infrastructure (production facilities, distribution systems, retail stations) - $900 billion (over a decade) Does this make sense?