6. 20-fold increase from 1850 to 2000. Fossil fuels supplied 80% of the world’s energy in 2000 (Holdren 2007)
7. Oil consumption in selected countries World energy demand is projected to increase by 50% by 2030.
8. Biofuel production is viable if crude oil prices stay above $55/barrel. Global vegetable oil production (150 Mt) = 10 d global fossil fuel consumption.
9. Plans for annual growth in biofuel production…2010/12 Joachim von Braun, IFPRI, August 2007 Costs of feedstock dominate costs Ethanol: 50-70%; Biodiesel: 70-80%
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11. Gross energy yield of various biofuel crops Liska and Cassman. 2007. J. Biobased Materials and Bioenergy * BD – biodiesel; E – Ethanol Crop yields: 2003-2005 average (FAOSTAT) Conversion yields: corn,0.399 L/kg; cassava, 0.137 L/kg; soybean 0.205 L/kg; rapeseed, 0.427 L/kg 39 1863 14 Brazil Cassava-E 18 552 3 USA Soybean-BD 21 641 2 Canada Rapeseed-BD 79 3751 9 USA Maize-E 124 5865 74 Brazil Sugarcane-E 195 5920 21 Malaysia Oil Palm-BD GJ/ha L/ha Mg/ha Energy Biofuel Yield Country Crop-biofuel*
12. Gross energy yield and net GHG reduction estimates for food-crop biofuel systems Liska and Cassman. 2007. J. Biobased Materials and Bioenergy Gross energy values: two largest producers in the world Net GHG gas reductions: literature summary Gross energy yield (GJ/ha)
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15. 42% 34% % of maize production, assuming 34 Mha area harvested and trend- line yield increase Expansion of USA maize-ethanol production 22% K. Cassman, Univ. of Nebraska
17. U.S. maize yields USA corn yield and irrigation (red hatched) by county (2004-2006 average). Source: National Agricultural Statistics Service, USDA. Liska and Cassman. 2007. J. Biobased Materials and Bioenergy
19. CH 4 Grain NO 3 leaching N 2 O CO 2 A. Liska et al., UNL, 2007 Technologies to improve maize-ethanol systems Thermal energy CH 4 Methane biodigestor (6) Closed-loop system (-56% energy) Biofertilizer CO 2 Maize & soybean production (1) Improve management (2) Increase NUE (10%) Grain Stillage CO 2 Ethanol Distillers grain Ethanol plant (3) Starch content 72 75% (4) Conversion efficiency 91 97% (enzymes, microbes) N 2 O CH 4 Manure, urine Meat Cattle feedlot (5) Directly use wet distillers grain (-26% energy) NO 3 leaching
20. Technological improvements Yield NUE Genetics Engineering ALL CORN YIELD Ethanol yield: crop management vs. other technological improvements Black : National average yields and technology (Farrrell et al., 2006) Blue : High-yield irrigated corn-soybean system, CT A. Liska et al., UNL, 2007 0 1 2 3 4 5 6 7 8 3000 4000 5000 6000 7000 Ethanol yield (L/ha) 15.3 Mg/ha 8.7 Mg/ha
21. Technological improvements Ethanol biorefinery integration with livestock to avoid drying distiller’s grains and producing methane can DOUBLE corn-ethanol’s net energy efficiency. Energy Ratio: 1.3 -1.6 1.6 1.6 1.6 1.9 2.6 2.8 Black : National average yields and technology Blue : High-yield irrigated corn-soybean system, CT A. Liska et al., UNL, 2007 0 1 2 3 4 5 6 7 8 6 8 10 12 14 16 18 Net Energy Value (MJ/L) Yield NUE Genetics Engineering ALL
22. GHG emissions reduction (% and t CO 2 eq*) Maize production system Ethanol biorefineries *Based on a 100 million gal/yr production capacity A. Liska et al., UNL, 2007 80% 601000 t 67% 504000 t closed-loop facility 73% 544000 t 60% 447000 t natural gas, wet DG 63%, 478000 t 51% 381000 natural gas 39% 294000 t 26% 198000 t coal Advanced Irrigated USA average
23. First Commercial-Scale Closed Loop Biofuel Refinery, Mead, Nebraska www.e3biofuels.com Ethanol: 24 M gallons/yr Cattle: 28,000 head/yr
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25. Includes forecast for 2007 (FAO Rice Market Monitor, Sep. 2007) Rice area Rice production
30. In what systems can crop residues be removed without threatening long-term sustainability? R. Buresh (IRRI) & K. Sayre (CIMMYT) In irrigated rice monoculture systems, removal of straw does not cause a decline in soil organic matter. Partial Limited Wheat & maize Sole upland crop(s) Partial Limited Rice All Yes Maize or wheat Rice – wheat, rice-maize All Yes Rice Double rice All Yes Rice Triple rice Portion for removal Potential for removal Residue System
31. Dry Season 2006 (kt straw) Wet Season 2006 (kt straw) Seasonal rice straw availability in Thailand B. Gadde, JGSEE Bangkok
32. Straw conversion to biopower or biofuel Slightly modified from C. Menke, JGSEE Bangkok Straw Energy conversion Electricity Solid Liquid Gas Intermediate energy form Form of end use Mandatory step Harvest Collection Transport Baling Combustion Pyrolysis Biomethanation Gasification Fermentation Raw material processing Shredded Briquetting Form as received Heat Gaseous fuel Liquid fuel Hydrolysis As intermediate steps increase – efficiency goes down Thermal conversion
Main point: many of these technologies are at an early stage of development and, so far, they have mostly been investigated for larger-scale industrial use. Starch ethanol and biodiesel processes are widely used already, but cellulosic ethanol remains at a pre-commercial stage thus far and will probably not have major impact on the next 5-10 years. For example: At present, the initial capital investment cost to build a corn-grain ethanol plant in the U.S. is about $1 per gallon of ethanol production capacity. The capital cost for a cellulosic ethanol plant is, at present, estimated to be 10 times as much, i.e., $10 per gallon capacity.
Trendline yield in 2007 is 9300 kg/ha, on 34.6 Mha, tottal production in 2007 = 322 Mt. yield increase is 112 kg/ha-yr, and estimated maize area in future years is 34 Mha, and probably less due to balance needed for soybean area.
There are other examples for such closed cycles at pilot stage: Oilseed biodiesel + high protein animal feed after oil extraction with wheat straw used to provide heat and power the process New Zealand (R. Sims): Fractionate biomass into various components, washing, pre-heating, hydrolysis of hemicellulose to chemicals such as furfural, lignin, and dried cellulose