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Biomass & Biofuels Bio-diesel. San Jose State University FX Rongère November 2007. Biochemical Conversion. Thermochemical Conversion. Extraction. Anaerobic Digestion. Fermentation. Direct Combustion. Gasification. Pyrolysis Liquefaction. Steam. Gas. Oil. Charcoal. Biogas. Ethanol.
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Biomass & BiofuelsBio-diesel San Jose State University FX Rongère November 2007
Biochemical Conversion Thermochemical Conversion Extraction Anaerobic Digestion Fermentation Direct Combustion Gasification Pyrolysis Liquefaction Steam Gas Oil Charcoal Biogas Ethanol Bio-diesel Heat Electricity Transportation Biofuels • Biofuels cover a broad range of technologies and applications: Source: From Boyle, Renewable Energy, 2nd edition, 2004
Transportation fuels • The U.S. uses 130 billion gallons of gasoline and 41 billion gallons of diesel fuel per year made from oil of which 65% is imported • Transportation is the first source of CO2, about 2,000 MM tons per year in the USA Source: EPA, Inventory of U.S. Green House Gas Emissions and Sinks 1990-2006 April, 2008
Diesel Engine • Grand Prix at the World Fair in Paris in 1900 powered by peanut oil. • “The use of vegetables oils for engine fuels may seem insignificant today but such oils may become in the course of the time as important as the petroleum and the coal tar products of the present time” Rudolph Diesel 1912
Bio-diesel • Definition: • Biodiesel is a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B 100. • It may substitutefossil diesel in vehicle engines, either as 100% biodiesel B100 or partially in a blend labeled: Bn • Invented in 1937 by G. Chavanne of the University of Brussels (Belgium) • Improvement patented by Expedito Parente (Brazil) in 1977 • To be certified, Biodiesel must meet the specifications of ASTM D 6751
Advantages • Non-toxic and bio-degradable • Performance and lubrication improvements • Does not contain glycerin • May be blended with fossil-diesel • Does not required high energy to produce • Broad feed stock
Biodiesel is booming Diesel consumption in the USA: 41b Gallons/year
In other countries • Germany is the worldwide leader for bio-diesel consumption with 750 MM Gal in 2006 Diesel prices at a local filling station in Kafertal, Mannheim, on 03-03-2007. Photo taken by Bob Tubbs.
The Basic Recipe • Transesterification: 100 lb oil + 21.71 lb methanol + 1 lbof NaOH or KOH as acatalyst 100.45 lb biodiesel + 10.40 lb glycerol + 10.86 lb XS methanol Transesterification
Chemistry Glycerin • Vegetable oils: soybean, canola, palm, etc. • Animal fats: beef tallow, lard, Chicken fat Biodiesel Oil
Water is the enemy • Water + Triglyceride Fatty Acids • Fatty Acids + KOH Soap • Soap gel at ambient temperature • Soap makes the glycerin separation difficult
Preferred Feedstock • Value of Biodiesel feedstock varies with the amount of free fatty acids they contain: • Refined vegetable oils < 0.05% • Crude soybean oil 0.3-0.7% • Restaurant waste grease 2-7% • Animal fat 5-30% • Trap grease 75-100% • Price decreases as FFAs increase but processing demands increase, also. • Not suitable for high FFA feeds because of soap formation.
Reaction time is a limiting factor • Transesterification reaction will proceed at ambient (70°F) temperatures but needs 4-8 hours to reach completion. • Reaction time can be shortened to 2-4 hours at 105°F and 1-2 hours at 140°F. • Higher temperatures will decrease reaction times but require pressure vessels because methanol boils at 148°F (65°C). • High shear mixing and use of cosolvents have been proposed to accelerate reaction.
Industrial Process Source: Community Fuels
Feedstock • Feedstock accounts for 70 –80% of total costs • Majority of U.S. plants operate on soybean oil only • All crops demand different: • Soils • Water • Collection • Crushing • Meal Source: Community Fuels
5.6 x 109 cal from 42.5 bu/ac Biodiesel Soy meal F P Energy Consumption for biodiesel Production • Biodiesel generation requires less energy but the yield for Soybean is lower than for corn ethanol: = 23,000 MM BTU 1 acre 42.5 bushels of Soybean 53 Gallons of Biodiesel 7,400 MM BTU Source: John Duxbury Update on the Biofuel Debate: Energetics, GHG Emissions, Strategy Crop and Soil Sciences Cornell University Today, biodiesel production (250 MM Gallons) represent 5 MM acres of Soybean
Area for current production • 250 MM Gal of Biodiesel -> 5 MM Acre of Soybean 100 km 200 km 0.6% of US Diesel consumption
Biodiesel Feedstock Jatropha Canola Sunflower Soybean Safflower Mustard
Biodiesel cost • Bio-diesel may be competitive with petro-diesel to day Wholesale price: $3.14 http://tonto.eia.doe.gov/oog/info/gdu/gasdiesel.asp Source: Community Fuels
Price is driven by the Market • Soybean price has tripled since Jan 2006
Algae www.solixbiofuels.com Project of algae farm by Solix, Inc.
Algae promise • 100 times more biodiesel by acre • Up to 70% of algae biomass is usable oils • Algae does not compete for land and space with other agricultural crops • Algae can survive in water of high salt content and use water that was previously deemed unusable
Algae process CO2 Nutrients Biodiesel O2 70% Fat 30% Cellulose
Current Development • Feasibility has been demonstrated in 80s and 90s by NREL • Cost is still an issue with target between $1.40 to $4.40 (NREL) – Petro-diesel cost: Wholesale price: $2.30 Source: http://tonto.eia.doe.gov/oog/info/gdu/gasdiesel.asp