Biomass & BiofuelsBio-diesel
San Jose State University
FX RongèreNovember 2007
Biofuels
Biofuels cover a broad range of technologies and applications:
Thermochemical Conversion
Direct Combustion
Direct Combustion
Gasification
Gasification
PyrolysisLiquefaction
PyrolysisLiquefaction
Biochemical Conversion
Anaerobic Digestion
Anaerobic Digestion
Fermentation
Fermentation
Extraction
Extraction
Heat Electricity Transportation
Steam Gas Oil Charcoal Bio-dieselBiogas Ethanol
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
CO2 Generation USA 2006
Transportation
31%
Electricity
Generation
39%
Industrial
14%
Commercial
4%
Non-Energy
use
7%
Residential
5%
Source: EPA, Inventory of U.S. Green House Gas Emissions and Sinks 1990-2006 April, 2008
CO2 Generation California 1999
Transportation
58%Electricity
Generation
16%
Industrial
13%
Commercial
4%Residential
9%
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 substitute fossil 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
ASTM D6751Property Method Limits Units
Flash point, closed cup D 93 130 min ° C
Water and sediment D 2709 0.050 max % volume
Kinematic viscosity, 40 ° C D 445 1.9 – 6.0 mm2/s
Sulfated ash D 874 0.020 max wt. %
Total Sulfur D 5453 0.05 max wt. %
Copper strip corrosion D 130 No. 3 max -
Cetane number D 613 47 min -
Cloud point D 2500 Report to customer ° C
Carbon residue D 4530 0.050 max wt. %
Acid number D 664 0.80 max mg KOH/g
Free glycerin D 6584 0.020 wt. %
Total glycerin D 6584 0.240 wt. %
Phosphorus D 4951 0.0010 wt. %
Vacuum distillation end point
D 1160 360 °C max, at T-90 % distilled
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 stockFuel type MJ /l MJ /kg kBTU/GalRegular Gasoline 34.8 44.4 125.0Ethanol 23.5 31.1 84.4Diesel 38.6 45.4 138.6Biodiesel 35.0 39.8 125.7
Biodiesel is booming
Historic U.S. Biodiesel Production
0
50
100
150
200
250
300
1999
2000
2001
2002
2003
2004
2005
2006
Million
s of
Gal
lons
Diesel consumption in the USA: 41b Gallons/year
Bio-diesel plants (2007)
In other countries
Germany is the worldwide leader for bio-diesel consumption with 750 MM Gal in 2006
Biodiesel Production Worldwide
0
200
400
600
800
1,000
1,200
1,400
1995 1997 1999 2001 2003 2005
MM
Gal
/year
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 lb of NaOH or KOH as a catalyst
100.45 lb biodiesel
+ 10.40 lb glycerol + 10.86 lb XS methanol
Transesterification
Chemistry O O || || CH2 - O - C - R1 CH3 - O - C - R1
| | O O CH2 - OH | || || | CH - O - C - R2 + 3 CH3OH => CH3 - O - C - R2 + CH - OH | (KOH) | | O O CH2 - OH | || || CH2 - O - C - R3 CH3 - O - C - R3
Triglyceride methanol mixture of fatty esters glycerin
OilBiodiesel
Vegetable oils: soybean, canola, palm, etc. Animal fats: beef tallow, lard, Chicken fat
Glycerin
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 ProcessSource: 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
0 20 40 60 80 100
Cost
Products
Soybean
% of Total Energy
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:
Source: John Duxbury Update on the Biofuel Debate: Energetics, GHG Emissions, Strategy Crop and Soil Sciences Cornell University
42.5 bushels of Soybean
53 Gallons of Biodiesel7,400 MM BTU
1 acre
Today, biodiesel production (250 MM Gallons) represent 5 MM acres of Soybean
= 23,000 MM BTU
Area for current production
250 MM Gal of Biodiesel -> 5 MM Acre of Soybean
200 km
100 km
0.6% of US Diesel consumption
Biodiesel Feedstock
Sunflower Jatropha Canola
Soybean Safflower Mustard
Biodiesel cost
Bio-diesel may be competitive with petro-diesel to day
Wholesale price: $3.14
Source: Community Fuels http://tonto.eia.doe.gov/oog/info/gdu/gasdiesel.asp
Price is driven by the Market
Soybean price has tripled since Jan 2006
Algae
Project of algae farm by Solix, Inc. www.solixbiofuels.com
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
O2
70% Fat30% Cellulose
Biodiesel
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
Summary BioFuels
Today % Consumption Potential % ConsumptionCombustion Steam Turbine 4 TWh/ y 1.5% 30 TWh/ y 10.2%
GasificationMethane, Hydrogene IGCC 38 TWh/ y 12.7%
Combustion Steam Turbine 0.5 TWh/ y 0.2% 30 TWh/ y 10.2%
GasificationMethane, Hydrogene IGCC 38 TWh/ y 12.9%
Diesel EngineGas TurbineStirling EngineDiesel EngineGas TurbineStirling Engine
Fermentation Ethanol Gasoline Engine 7,500 MM Gal/ y 5.8% ? ?Esterification Bio-diesel Diesel Engine 250 MM Gal/ y 0.6% ? ?
0.7%
MSW
Manure
Wood
MethaneAnaerobic Digestion
Anaerobic Digestion
Methane
Specialized Crops
7.1%Cal
ifor
nia
USA
1.3%
Electricity
Transportation
2 TWh/ y 21 TWh/ y
4 TWh/ y