Biomass Energy
Professor Stephen Lawrence
Leeds School of Business
University of Colorado – Boulder
1
Biomass Agenda
• Bioenergy Overview
• Biomass Resources
• Creating Energy from Biomass
• Biomass Economics
• Biomass Environmental Issues
• Promise of Bioenergy
• Ethanol Production
2
BioEnergy Overview
3
Global Energy Sources
2002
4
Boyle, Renewable Energy, Oxford University Press (2004)
Renewable Energy Use
– 2001
5
Boyle, Renewable Energy, Oxford University Press (2004)
Bioenergy Cycle
6
http://www.repp.org/bioenergy/bioenergy-cycle-med2.jpg
Bioenergy Cycle
7
Boyle, Renewable Energy, Oxford University Press (2004)
Carbon Cycle
8
Boyle, Renewable Energy, Oxford University Press (2004)
Commercial
Carbon Cycle
9
US Energy Cropland
10
http://www.cbsnews.com/htdocs/energy/renewable/map_bioenergy_image.html
US Biomass Resources
11
Biomass
Resource Potential
12
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.gif
Biomass Basic Data
13
Boyle, Renewable Energy, Oxford University Press (2004)
Solar Energy Conversion
1 hectare = ~2.5 acres 14
Boyle, Renewable Energy, Oxford University Press (2004)
Boiling 1l of Water
15
Boyle, Renewable Energy, Oxford University Press (2004)
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
16
Transportation 139 147 174 239 296
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.html
Bioenergy Technologies
17
Boyle, Renewable Energy, Oxford University Press (2004)
Biomass Resources
18
Types of Biomass
19
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 20
http://www.eere.energy.gov/RE/bio_resources.html
Corn
21
http://www.geo.msu.edu/geo333/corn.html
Soybeans
22
http://agproducts.unl.edu/
Sorghum
23
http://www.okfarmbureau.org/press_pass/galleries/grainSorghum/
Sugar Cane Bagasse
24
http://www.nrel.gov/biomass/photos.html
Switchgrass
25
http://www.nrel.gov/biomass/photos.html
Hybrid Poplar
26
http://www.nrel.gov/biomass/photos.html
Corn Stover
27
http://www.nrel.gov/biomass/photos.html
Wood Chips & Sawdust
28
http://www.nrel.gov/biomass/photos.html http://www.energytrust.org/RR/bio/
Tracy Biomass Plant
Truck unloading wood chips that will fuel
the Tracy Biomass Plant, Tracy, California. 29
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.html
Municipal Solid Waste
30
http://www.eeingeorgia.org/eic/images/landfill.jpg
Creating Energy
from Biomass
31
Bioenergy Conversion
32
Boyle, Renewable Energy, Oxford University Press (2004)
Biomass Direct
Combustion
33
Boyle, Renewable Energy, Oxford University Press (2004)
Heat Energy Content
34
Boyle, Renewable Energy, Oxford University Press (2004)
MSW Power Plant
35
Boyle, Renewable Energy, Oxford University Press (2004)
Composition of MSW
36
Boyle, Renewable Energy, Oxford University Press (2004)
Integrated Waste Plant
37
Boyle, Renewable Energy, Oxford University Press (2004)
EU MSW Incineration
38
Boyle, Renewable Energy, Oxford University Press (2004)
Landfill Gasses
39
Boyle, Renewable Energy, Oxford University Press (2004)
Biorefinery
40
http://www.nrel.gov/biomass/biorefinery.html
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
41
http://www.nrel.gov/biomass/proj_biochemical_conversion.html
Thermochemical
Platform
• Direct Combustion
• Gasification
• Pyrolysis
42
http://www1.eere.energy.gov/biomass/thermochemical_platform.html
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
43
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
44
http://www.nrel.gov/biomass/photos.html
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
45
http://www1.eere.energy.gov/biomass/pyrolysis.html
Pyrolysis Schmatic
46
http://www1.eere.energy.gov/biomass/pyrolysis.html
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
47
http://www1.eere.energy.gov/biomass/other_platforms.html
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.
48
http://www1.eere.energy.gov/biomass/other_platforms.html
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
49
http://www.eere.energy.gov/RE/bio_fuels.html
Biodiesel Bus
50
http://www.nrel.gov/biomass/photos.html
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.
51
http://www1.eere.energy.gov/biomass/other_platforms.html
Biomass
Economics
52
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
53
http://www.eere.energy.gov/RE/bio_integrated.html
Landfill Gas Costs
54
Boyle, Renewable Energy, Oxford University Press (2004)
Switchgrass Econ
Total
Variable Total Fixed Ethanol Min
Tons Per Cost Per Cost Per Total Cost Price per
Acre Acre Acre Per Acre 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
55
http://www.agecon.uga.edu/~caed/Pubs/switchgrass.html
Energy Crop Potential
56
Michael Totten, Conservation International, January 27, 2006
Environmental
Impacts
57
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 58
http://www.eere.energy.gov/RE/bio_integrated.html
Heat and CO2 Content
59
Boyle, Renewable Energy, Oxford University Press (2004)
Net Life Cycle Emissions
60
Boyle, Renewable Energy, Oxford University Press (2004)
Crop Erosion Rates
SRWC = Short Rotation Woody Crops
61
Michael Totten, Conservation International, January 27, 2006
Biocide Requirements
Short Rotation
Woody Crops 62
Michael Totten, Conservation International, January 27, 2006
Promise of
Bioenergy
63
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
64
http://www.eere.energy.gov/RE/bio_resources.html
Benefits of Bioenergy
Multiple benefits would accrue:
• 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.
65
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.
66
Nathaniel Greene et al., Growing Energy, www.bioproducts-bioenergy.gov/pdfs/NRDC-Growing-Energy-Final.3.pdf.
US Grows its Gas
TODAY & BUSINESS AS USUAL NEXT DECADE & FUTURE
30 million hectares soy 30 million hectares switchgrass
Switchgrass 1 to 3x protein productivity +
5 to 10 x mass productivity of soybeans
animal Cellulose
oils animal
protein oils hydrolyzed into
feed protein
30 billion
feed
gallons ethanol
67
http://thayer.dartmouth.edu/thayer/rbaef/.
Fuel Efficiency vs. Land
68
Bioenergy Forecasts
69
Boyle, Renewable Energy, Oxford University Press (2004)
One Scenario
Semi-Efficient, Ambitious Renewable Energy Scenario 70
Michael Totten, Conservation International, January 27, 2006
Ethanol Production
71
Ethanol Yields
72
Boyle, Renewable Energy, Oxford University Press (2004)
Ethanol Production Plant
73
http://www.nrel.gov/biomass/photos.html
74
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
75
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
76
In comparison, US consumed
an 140,000 million gallons of
gasoline in 2004
77
US Ethanol Facilities
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Ethanol by State
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Ethanol Fuel Use 2003
80
Ethanol Use by Market
Federal Reformulated Gasoline
Required year round in high pollution metro areas
e.g. L.A., San Diego, Dallas, Houston, Washington, D.C.
Federal Winter Oxygenated Fuels
Required during winter in selected high pollution metro areas
e.g. Denver, Phoenix, Las Vegas 81
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) 82
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)
83
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).
84
Source: EPA (http://www.epa.gov/mtbe/gas.htm)
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) 85
State MTBE Bans
86
Corn Use for Ethanol
87
Corn Use by Segment
88
Sorghum Use by Segment
89
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
90
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%
91
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
92
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
Cellulosic Ethanol
Energy 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
93
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
Ethanol
Energy 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
94
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
U.S. Petroleum Supply
95
MMBPD
Source: Department of Energy/Energy Information Agency
Ethanol
Energy 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
96
Source: Federal University of Rio de Janeiro
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?
97
Source: American Coalition for Ethanol (http://www.ethanol.org/documents/ACERFSSummary.pdf)
Next Week:
Midterm Review
98
Extra Slides
99
Biomass Basics
100
http://www.eere.energy.gov/RE/bio_basics.html
BioPower Electricity
• Direct Combustion
– Burn biomass to create steam
• Co-Firing
– Mix biomass with coal in coal plants
– Economically attractive
• Gasification
• Pyrolysis
• Anaerobic Digestion
101
http://www.eere.energy.gov/RE/bio_biopower.html
Integrated Systems
102
http://www.eere.energy.gov/RE/bio_integrated.html
Biomass Resources
• Herbaceous Energy Crops
• Woody Energy Crops
• Industrial Crops
• Agricultural Crops
• Aquatic Crops
• Agricultural Crop Residues
• Forestry Residues
• Municipal Waste
• Animal Waste
103
http://www.eere.energy.gov/RE/bio_resources.html
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
104
http://www1.eere.energy.gov/biomass/sugar_platform.html
Biorefinery Platforms
105
http://www1.eere.energy.gov/biomass/
106
Boyle, Renewable Energy, Oxford University Press (2004)
Average UK Fuel Prices
107
Boyle, Renewable Energy, Oxford University Press (2004)
Energy Crop Yields
108
Boyle, Renewable Energy, Oxford University Press (2004)
Biodiversity friendly Bioenergy?
Perennial prairie grasses
109
110
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.
111
http://www1.eere.energy.gov/biomass/other_platforms.html
Direct Hydrothermal
Liquifaction
112
Thermochemical R&D
113
Simple vs. CCGT Plant
114
Boyle, Renewable Energy, Oxford University Press (2004)
Carbon/Solar Cycle
115