Renewable%20Biofuel%20Energy%20Primer

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Renewable Biofuel Energy Primer
Acknowledgements Nebraska Energy
Office University of Nebraska-Lincoln Institute
of Agriculture and Natural Resources Department
of Agronomy and Horticulture Development Team
Dr. Ken Cassman, Dr. Adam Liska, Leah
Sandall, Patty Hain
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Biofuel Energy System
Solar radiation
O2
Transportation
CO2
Ethanol Plant
Crop residue
CO2
Value-added products
Cattle feedlot
Decomposition
Cars
Soil organic matter
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Photosynthesis Converting Sunlight into Plant
Biomass
Light
CO2
O2
Photosynthesis process of converting light
energy using water (H2O) and carbon
dioxide (CO2) into oxygen (O2) and sugars
(carbohydrate).
Rain
Irrigation
Nitrogen (N)
Phosphorous (P)
Calcium (Ca)
Iron (Fe)
Potassium (K)
Essential soil nutrients
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Corn Grain Composition and Energy Content
Percent of Energy Content
Percent by weight
Sugar and starch (72)
Sugar and starch (67)
Protein (10) Oil (4) Fiber (13)
Protein (12) Oil (9) Fiber (13)
Sugar and starch (carbohydrates) portion of the
kernel used to make ethanol.
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Fermentation

• Fermentation microbial process of converting
• starch and sugars to alcohol

1970s-present
6000-8000 BC
1700s-1800s
1930s
U.S. prohibition
Primitive production of alcohol
Commercial production of beer, bourbon/whiskey
Industrial ethanol production for biofuel
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Ethanol Production Plant
Consumable Alcohol (Beer)
Corn
Fermentation
Enzymes
Yeast
(water yeast/microbes)
190 proof Ethanol
Distillers Grains and syrup separation
Distillation towers
2.7 gallons of ethanol 6.7 lbs of distillers
grains
One bushel of corn
natural gas and steam
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By-products from Grain Ethanol Production

• Distillers grains used for livestock feed
• can replace 20-40 of cattle rations
• can be dried for long-distance shipping (energy
  intensive) or fed to feedlots nearby without
  drying
• Solubles contain oil and proteins
• mixed with distillers grains
• processed into other value-added products

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How much grain is needed?

• The Energy Security Act of 2005 and Renewable
  Fuels Standard (RFS)
• 7.5 billion gallons of ethanol by 2012
• At 2.7 gal/bu corn 2.8 billion bushels of corn
  needed
• Total U.S. corn production (2005) 11 billion
  bushels
• Average rate of yield gain 1.2 / year
• By 2012, 7.5 billion gallons of ethanol will
  require 23 of 11.9 billion bushel U.S. corn crop

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Amount of Grain Needed

• Technological advances continue to improve
  ethanol production
• Distillers grains replace grain used for
  livestock feed
• Therefore, total grain requirements are likely to
  be about 15 of the U.S. corn crop in an average
  year

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Is Ethanol Production Energy Efficient?

• One measure of energy efficiency ratio of
  energy in ethanol biofuel divided by the energy
  used in producing, transporting, and converting
  corn to ethanol
• Ratio greater than 1.0 means more energy is
  produced than is consumed
• Based on current average values, energy ratio
  1.2

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Energy Efficiency Will Improve

• Due to
• Increases in corn yield and production efficiency
  
• Increases in ethanol conversion efficiency
• Better integration of ethanol and livestock
  production facilities
• Reducing transportation distance for distillers
  grain
• Use of manure, reducing need for natural gas to
  run ethanol plants

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How Does Ethanol Reduce Use of Foreign Oil?

• A recent economic impact study indicates that an
  8 billion gallon RFS would reduce U.S. imported
  oil from 67 to 62
• Would reduce oil imports by 2 billion barrels
• For every gallon of oil used in lifecycle of
  ethanol production, about 8 gallons of ethanol
  are produced

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Is Grain-Ethanol Production Good for the
Environment?

• Ethanol use in gasoline decreases emissions of
  environmental pollutants
• Greenhouse gas (GHG) emissions reduced because
  instead of burning fossil fuels in cars
  (increasing GHG) the use of ethanol recycles
  CO2 into atomosphere
• Implementing farming practices with increased
  efficiency, reduces production costs and helps
  protect the environment

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Use of Oil Crops to Produce Biodiesel Fuels

• Soybean, canola, and other crops have seed with
  high percentage of oil

• Oil from seeds can be extracted
• and processed into biodiesel fuel,
• replacing diesel fuel made from
• imported oil

• Current biodiesel production is small but the
  2005
• Energy Security Act provides incentives to expand
• this fuel source

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Future Developments

• New ethanol production from non-grain plant
  material
• Converting cellulose in plant tissues to sugars
• Plant stalks and leaves contain cellulose
• Plant material from corn (corn stover),
  switchgrass, wood residue
• Currently costs more to produce ethanol from
  biomass than from grain
• With technology improvements, it is estimated
  that ethanol production could produce up to 20
  of total U.S. transportation fuel

Switchgrass
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References

• Farrell et al. Ethanol Can Contribute to Energy
  and Environmental Goals. Science 311 506-508,
  2006.
• Klass et al. Biomass for Renewable Energy,
  Fuels, and Chemicals. Academic Press 1998.
• Renewable Fuels Association. From Niche to
  Nation Ethanol Industry Outlook, 2006.
  http//www.ethanolrfa.org/
• Shapouri, H., J.A. Duffield, M. Wang. The Energy
  Balance of Corn Ethanol An Update, USDA-ERS,
  2002.
• Shapouri, H., and P. Gallagher. USDAs 2002
  Ethanol Cost-of-Production Survey. USDA-ERS, AER
  no. 841, 2005.
• Wang, M., C. Saricks, D. Santini. Effects of
  Fuel Ethanol Use on Fuel-Cycle Energy and
  Greenhouse Gas Emissions. Argonne National
  Laboratory, Department of Energy. ANL/ESD-38,
  1999.
• Wyman, C.E. (Ed.). Handbook on Bioethanol
  Production and Utilization. Taylor Francis,
  1996.