bioenergy
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1
Biomass Energy
Professor Stephen LawrenceLeeds School of Business
University of Colorado – Boulder
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Biomass Agenda
• Bioenergy Overview
• Biomass Resources
• Creating Energy from Biomass
• Biomass Economics
• Biomass Environmental Issues
• Promise of Bioenergy
• Ethanol Production
3
BioEnergy Overview
4
Global Energy Sources 2002
Boyle, Renewable Energy, Oxford University Press (2004)
5
Renewable Energy Use – 2001
Boyle, Renewable Energy, Oxford University Press (2004)
6
Bioenergy Cycle
http://www.repp.org/bioenergy/bioenergy-cycle-med2.jpg
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Bioenergy Cycle
Boyle, Renewable Energy, Oxford University Press (2004)
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Carbon Cycle
Boyle, Renewable Energy, Oxford University Press (2004)
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Commercial Carbon Cycle
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US Energy Cropland
http://www.cbsnews.com/htdocs/energy/renewable/map_bioenergy_image.html
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US Biomass Resources
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Biomass Resource Potential
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.gif
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Biomass Basic Data
Boyle, Renewable Energy, Oxford University Press (2004)
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Solar Energy Conversion
Boyle, Renewable Energy, Oxford University Press (2004)
1 hectare = ~2.5 acres
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Boiling 1l of Water
Boyle, Renewable Energy, Oxford University Press (2004)
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Biomass Energy Production
Sector/Source 2000 2001 2002 2003 2004P
Total 2,907 2,640 2,648 2,740 2,845
Wood Energy Total 2,257 1,980 1,899 1,929 1,989
Residential 433 370 313 359 332
Commercial 53 40 39 40 41
Industrial 1,636 1,443 1,396 1,363 1,448
Electric Powera 134 126 150 167 168
Waste Energy Total 511 514 576 571 560
MSW/Landfill Gas 400 419 467 440 443
Commercial 41 35 37 42 43
Industrial 64 74 87 85 88
Electric Powera 295 310 343 314 312
Other Biomassb 111 95 108 131 117
Commercial 6 4 5 6 5
Industrial 81 76 81 85 84
Electric Powera 23 14 22 41 28
Alcohol Fuelsc 139 147 174 239 296
Transportation 139 147 174 239 296
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.html
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Bioenergy Technologies
Boyle, Renewable Energy, Oxford University Press (2004)
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Biomass Resources
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Types of Biomass
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Biomass Resources
• Energy Crops– Woody crops– Agricultural crops
• Waste Products– Wood residues– Temperate crop wastes– Tropical crop wastes– Animal wastes– Municipal Solid Waste (MSW)– Commercial and industrial wastes
http://www.eere.energy.gov/RE/bio_resources.html
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Corn
http://www.geo.msu.edu/geo333/corn.html
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Soybeans
http://agproducts.unl.edu/
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Sorghum
http://www.okfarmbureau.org/press_pass/galleries/grainSorghum/
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Sugar Cane Bagasse
http://www.nrel.gov/biomass/photos.html
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Switchgrass
http://www.nrel.gov/biomass/photos.html
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Hybrid Poplar
http://www.nrel.gov/biomass/photos.html
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Corn Stover
http://www.nrel.gov/biomass/photos.html
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Wood Chips & Sawdust
http://www.nrel.gov/biomass/photos.html http://www.energytrust.org/RR/bio/
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Tracy Biomass Plant
Truck unloading wood chips that will fuel the Tracy Biomass Plant, Tracy, California.
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.html
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Municipal Solid Waste
http://www.eeingeorgia.org/eic/images/landfill.jpg
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Creating Energy from Biomass
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Bioenergy Conversion
Boyle, Renewable Energy, Oxford University Press (2004)
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Biomass Direct Combustion
Boyle, Renewable Energy, Oxford University Press (2004)
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Heat Energy Content
Boyle, Renewable Energy, Oxford University Press (2004)
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MSW Power Plant
Boyle, Renewable Energy, Oxford University Press (2004)
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Composition of MSW
Boyle, Renewable Energy, Oxford University Press (2004)
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Integrated Waste Plant
Boyle, Renewable Energy, Oxford University Press (2004)
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EU MSW Incineration
Boyle, Renewable Energy, Oxford University Press (2004)
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Landfill Gasses
Boyle, Renewable Energy, Oxford University Press (2004)
40
Biorefinery
http://www.nrel.gov/biomass/biorefinery.html
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Sugar Platform
1. Convert biomass to sugar or other fermentation feedstock
2. Ferment biomass intermediates using biocatalysts• Microorganisms including yeast and
bacteria;
3. Process fermentation product • Yield fuel-grade ethanol and other fuels,
chemicals, heat and/or electricity
http://www.nrel.gov/biomass/proj_biochemical_conversion.html
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Thermochemical Platform
• Direct Combustion
• Gasification
• Pyrolysis
http://www1.eere.energy.gov/biomass/thermochemical_platform.html
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Gasification
• Biomass heated with no oxygen
• Gasifies to mixture of CO and H2
– Called “Syngas” for synthetic gas
• Mixes easily with oxygen
• Burned in turbines to generate electricity– Like natural gas
• Can easily be converted to other fuels, chemicals, and valuable materials
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Biomass Gasifier
• 200 tons of wood chips daily
• Forest thinnings; wood pallets
• Converted to gas at ~1850 ºF
• Combined cycle gas turbine
• 8MW power output McNeil Generating Station biomass gasifier – 8MW
http://www.nrel.gov/biomass/photos.html
45
Pyrolysis
• Heat bio-material under pressure– 500-1300 ºC (900-2400 ºF)– 50-150 atmospheres– Carefully controlled air supply
• Up to 75% of biomass converted to liquid
• Tested for use in engines, turbines, boilers
• Currently experimental
http://www1.eere.energy.gov/biomass/pyrolysis.html
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Pyrolysis Schmatic
http://www1.eere.energy.gov/biomass/pyrolysis.html
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Anaerobic Digestion
• Decompose biomass with microorganisms – Closed tanks known as anaerobic digesters
– Produces methane (natural gas) and CO2
• Methane-rich biogas can be used as fuel or as a base chemical for biobased products.
• Used in animal feedlots, and elsewhere
http://www1.eere.energy.gov/biomass/other_platforms.html
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Carbon Rich Platform
• Natural plant oils such as soybean, corn, palm, and canola oils– In wide use today for food and chemical applications
• Transesterification of vegetable oil or animal fat produces fatty acid methyl ester– Commonly known as biodiesel.
• Biodiesel an important commercial air-emission reducing additive / substitute for diesel fuel– could be platform chemical for biorefineries.
http://www1.eere.energy.gov/biomass/other_platforms.html
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BioFuels
• Ethanol– Created by fermentation of starches/sugars– US capacity of 1.8 billion gals/yr (2005)– Active research on cellulosic fermentation
• Biodiesel– Organic oils combined with alcohols– Creates ethyl or methyl esters
• SynGas Biofuels– Syngas (H2 & CO) converted to methanol, or
liquid fuel similar to diesel
http://www.eere.energy.gov/RE/bio_fuels.html
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Biodiesel Bus
http://www.nrel.gov/biomass/photos.html
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Plant Products Platform
• Selective breeding and genetic engineering
• Develop plant strains that produce greater amounts of desirable feedstocks or chemicals
• Even compounds that the plant does not naturally produce
• Get the biorefining done in the biological plant rather than the industrial plant.
http://www1.eere.energy.gov/biomass/other_platforms.html
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Biomass Economics
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Economic Issues
• Sustainable Development– Move toward sustainable energy production
• Energy Security– Reduce dependence on imported oil
• Rural Economic Growth– Provide new crops/markets for rural business
• Land Use– Better balance of land use
http://www.eere.energy.gov/RE/bio_integrated.html
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Landfill Gas Costs
Boyle, Renewable Energy, Oxford University Press (2004)
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Switchgrass Econ
Tons Per Acre
Total Variable Cost Per
Acre
Total Fixed Cost Per
AcreTotal Cost
Per Acre
Ethanol Min Price per
Gallon
2 $131.00 $66.50 $197.50 $2.47
3 $87.33 $44.33 $131.67 $1.65
4 $65.50 $33.25 $98.75 $1.23
5 $52.40 $26.60 $79.00 $0.99
6 $43.67 $22.17 $65.83 $0.82
7 $37.43 $19.00 $56.43 $0.71
8 $32.75 $16.63 $49.38 $0.62
9 $29.11 $14.78 $43.89 $0.55
10 $26.20 $13.30 $39.50 $0.49 http://www.agecon.uga.edu/~caed/Pubs/switchgrass.html
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Energy Crop Potential
Michael Totten, Conservation International, January 27, 2006
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Environmental Impacts
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Environmental Issues
• Air Quality– Reduce NOx and SO2 emissions
• Global Climate Change– Low/no net increase in CO2
• Soil Conservation– Soil erosion control, nutrient retention, carbon
sequestration, and stabilization of riverbanks.
• Water Conservation– Better retention of water in watersheds
• Biodiversity and Habitat– Positive and negative changes
http://www.eere.energy.gov/RE/bio_integrated.html
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Heat and CO2 Content
Boyle, Renewable Energy, Oxford University Press (2004)
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Net Life Cycle Emissions
Boyle, Renewable Energy, Oxford University Press (2004)
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Crop Erosion Rates
Michael Totten, Conservation International, January 27, 2006
SRWC = Short Rotation Woody Crops
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Biocide Requirements
Michael Totten, Conservation International, January 27, 2006
Short RotationWoody Crops
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Promise of Bioenergy
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Biomass Infrastructure
• Biomass Production Improvements– Genetics, breeding, remote sensing, GIS,
analytic and evaluation techniques
• Biomass Material Handling– Storage, handling, conveying, size reduction,
cleaning, drying, feeding systems, systems
• Biomass Logistics and Infrastructure– Harvesting, collecting, storing, transporting,
other biomass supply chain elements
http://www.eere.energy.gov/RE/bio_resources.html
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Multiple benefits would accrue:
www.bioproducts-bioenergy.gov/pdfs/NRDC-Growing-Energy-Final.3.pdf.
Benefits of Bioenergy
• Rural American farmers producing these fuel crops would see $5 billion of increased profits per year.
• Consumers would see future pump savings of $20 billion per year on fuel costs.
• Society would see CO2 emissions reduced by 6.2 billion tons per year, equal to 80% of U.S. transportation-related CO2 emissions in 2002.
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Nathaniel Greene et al., Growing Energy, www.bioproducts-bioenergy.gov/pdfs/NRDC-Growing-Energy-Final.3.pdf.
Growing US Energy
• 2004 assessment by the National Energy Commission concluded that a vigorous effort in the USA to develop cellulosic biofuels between now and 2015 could:– Produce the first billion gallons at costs
approaching those of gasoline and diesel. – Establish the capacity to produce biofuels at
very competitive pump prices equivalent to roughly 8 million barrels of oil per day (122 billion gallons per year) by 2025.
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TODAY & BUSINESS AS USUAL30 million hectares soy
NEXT DECADE & FUTURE30 million hectares switchgrass
Switchgrass 1 to 3x protein productivity + 5 to 10 x mass productivity of soybeans
animal protein
feed
oils animal protein
feed
Cellulose hydrolyzed into
30 billion gallons ethanol
oils
http://thayer.dartmouth.edu/thayer/rbaef/.
US Grows its Gas
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Fuel Efficiency vs. Land
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Bioenergy Forecasts
Boyle, Renewable Energy, Oxford University Press (2004)
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One Scenario
Michael Totten, Conservation International, January 27, 2006
Semi-Efficient, Ambitious Renewable Energy Scenario
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Ethanol Production
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Ethanol Yields
Boyle, Renewable Energy, Oxford University Press (2004)
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Ethanol Production Plant
http://www.nrel.gov/biomass/photos.html
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Ethanol Production
• Corn kernels are ground in a hammermill to expose the starch
• The ground grain is mixed with water, cooked briefly and enzymes are added to convert the starch to sugar using a chemical reaction called hydrolysis.
• Yeast is added to ferment the sugars to ethanol.
• The ethanol is separated from the mixture by distillation and the water is removed from the mixture using dehydration
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Ethanol Production
• Energy content about 2/3 of gasoline– So E10 (10% ethanol, 90% gasoline) will
cause your gas mileage to decrease 3-4%
• Takes energy to create ethanol from starchy sugars – Positive net energy balance– Energy output/input = 1.67
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In comparison, US consumedan 140,000 million gallons ofgasoline in 2004
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US Ethanol Facilities
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Ethanol by State
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Ethanol Fuel Use 2003
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Federal Reformulated GasolineRequired year round in high pollution metro areas
e.g. L.A., San Diego, Dallas, Houston, Washington, D.C.
Federal Winter Oxygenated FuelsRequired during winter in selected high pollution metro areas
e.g. Denver, Phoenix, Las Vegas
Ethanol Use by Market
82
MTBE
• MTBE (methyl tertiary-butyl ether) – A chemical compound that is manufactured by the
chemical reaction of methanol and isobutylene– Used almost exclusively a fuel additive in gasoline– It is one of a group of chemicals commonly known as
"oxygenates" because they raise the oxygen content of gasoline.
– At room temperature, MTBE is a volatile, flammable and colorless liquid that dissolves rather easily in water.
Source: EPA (http://www.epa.gov/mtbe/gas.htm)
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MTBE
• Oxygen helps gasoline burn more completely, reducing tailpipe emissions from motor vehicles
• Oxygen dilutes or displaces gasoline components such as aromatics (e.g., benzene) and sulfur
• Oxygen optimizes the oxidation during combustion.
• Most refiners have chosen to use MTBE over other oxygenates primarily for its blending characteristics and for economic reasons
Source: EPA (http://www.epa.gov/mtbe/gas.htm)
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MTBE and The Clean Air Act
• The Clean Air Act Amendments of 1990 (CAA) require the use of oxygenated gasoline in areas with unhealthy levels of air pollution
– The CAA does not specifically require MTBE. Refiners may choose to use other oxygenates, such as ethanol
– Winter Oxyfuel Program: Originally implemented in 1992, the
CAA requires oxygenated fuel during the cold months in cities that have elevated levels of carbon monoxide
– Year-round Reformulated Gasoline Program: Since 1995, the CAA requires reformulated gasoline (RFG) year-round in cities with the worst ground-level ozone (smog).
Source: EPA (http://www.epa.gov/mtbe/gas.htm)
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MTBE and Groundwater Pollution
• MTBE has the potential to occur in high concentrations in groundwater
• Some MTBE has appeared in drinking water wells throughout the U.S
• Highly water soluble– Not easily absorbed into soil– Resists biodegradation
• Travels far from leak sources, – Hazard on a regional scale.
• Some states are banning MTBE
Source: Lawrence Livermore National Laboratory (http://www.llnl.gov/str/Happel.html)
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State MTBE Bans
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Corn Use for Ethanol
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Corn Use by Segment
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Sorghum Use by Segment
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Energy Policy Act of 2005
• Small Producer Biodiesel and Ethanol Credit– 10 cent per gallon tax credit – Up to 15 million gallons annually per producer– Expires year end 2008
• Fueling stations – 30% credit for cost of installing clean-fuel vehicle
refueling equipment– $30,000 maximum– e.g. E85
• 85% Ethanol, 15% gasoline• GM pushing their E85 vehicles as an alternative to hybrids• Seven SUV/Trucks, two sedans
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Energy Policy Act of 2005
• The Renewable Fuel Standard – Requires use of 7.5 billion gallons of biofuels by 2012
• includes ethanol and biodiesel
– Up from 3.4 billion gallons in 2004
• All refiners required to abide by targets– Credit trading mechanism in place
• For example, refiners in states with little or no ethanol production may buy credits from refiners in states with excess production
• Increased costs across the nation• Decrease oil imports by 2.1%
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Cellulosic Ethanol
• Ethanol produced from agricultural residues, woody biomass, fibers, municipal solid waste, switchgrass
• Process converts lignocellulosic feedstock (LCF) into component sugars, which are then fermented to ethanol
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
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Cellulosic EthanolEnergy Policy Act of 2005
• Minimum 250 million gallons/year by 2012
• Incentive grants for facility construction– 2006: $500 million– 2007: $800 million– 2008: $400 million
• Other research grants/production incentives– 2006 – 2010: $485 million
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
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EthanolEnergy Policy Act of 2005
• President Bush– Reduce our “addition to oil”
• Replace 75% of U.S. oil imports from the Middle East by 2025– But that’s just 4.3 million barrels/day– Total consumption of 26.1 million barrels/day
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
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U.S. Petroleum Supply
2004
8.6
1.86.2
3.3
2.6
Domestic Oil
Domestic Ethanol
Western Hemisphere
Europe/Africa
Persian Gulf
2025
5.1
5.3
6.7
3.2
5.8
Domestic Oil
Domestic Ethanol
Western Hemisphere
Europe/Africa
Persian Gulf
MMBPDSource: Department of Energy/Energy Information Agency
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EthanolEnergy Policy Act of 2005
• Brazil produces ethanol at $25/oil equivalent barrel– Adjusted price taking into account energy differences
between ethanol and oil– Compare $25/barrel to current oil price of $60+/barrel
• Largest commercial application of biomass energy in the world– Sugar cane used a feedstock
• Domestic automakers building flex-fuel vehicles
Source: Federal University of Rio de Janeiro
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Promoting Bioenergy
• Why not import ethanol from Brazil?• The U.S. imposes a $22/barrel import tariff on
Brazilian ethanol• So, are the ethanol subsidies in the EPAct05
just a payoff to the agricultural lobby?• Or, are we attempting to build a domestic
ethanol industry by subsidizing its early efforts?• How best to promote bioenergy?
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
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Midterm Review
Next Week:
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Extra Slides
100
Biomass Basics
http://www.eere.energy.gov/RE/bio_basics.html
101
BioPower Electricity
• Direct Combustion– Burn biomass to create steam
• Co-Firing– Mix biomass with coal in coal plants– Economically attractive
• Gasification
• Pyrolysis
• Anaerobic Digestion
http://www.eere.energy.gov/RE/bio_biopower.html
102
Integrated Systems
http://www.eere.energy.gov/RE/bio_integrated.html
103
Biomass Resources
• Herbaceous Energy Crops• Woody Energy Crops• Industrial Crops• Agricultural Crops• Aquatic Crops• Agricultural Crop Residues• Forestry Residues• Municipal Waste• Animal Waste
http://www.eere.energy.gov/RE/bio_resources.html
104
Sugar Platform
• Most plant material consists of cellulose– Not starch and starch and sugar
• Need to break cellulose into its sugars– Research underway to make economical
http://www1.eere.energy.gov/biomass/sugar_platform.html
105
Biorefinery Platforms
http://www1.eere.energy.gov/biomass/
106
Boyle, Renewable Energy, Oxford University Press (2004)
107
Average UK Fuel Prices
Boyle, Renewable Energy, Oxford University Press (2004)
108
Energy Crop Yields
Boyle, Renewable Energy, Oxford University Press (2004)
109
Biodiversity friendly Bioenergy?Perennial prairie grasses
110
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Other Platforms
• Biogas Platform• Carbon-Rich Chains Platform• Plant Products Platform
– Selective breeding and genetic engineering – develop plant strains that produce greater amounts of
desirable feedstocks or chemicals – even compounds that the plant does not naturally
produce– getting the biorefining done in the biological plant
rather than the industrial plant.
http://www1.eere.energy.gov/biomass/other_platforms.html
112
Direct Hydrothermal Liquifaction
113
Thermochemical R&D
114
Simple vs. CCGT Plant
Boyle, Renewable Energy, Oxford University Press (2004)
115
Carbon/Solar Cycle
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