Life Cycle assessment for bioenergybioenergy.psu.edu/shortcourses/2011LifeCycle/WhyL... · 8/1/2011...
Transcript of Life Cycle assessment for bioenergybioenergy.psu.edu/shortcourses/2011LifeCycle/WhyL... · 8/1/2011...
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LIFE CYCLE ASSESSMENT FOR
BIOENERGY
Charles D. Ray
Life Cycle Assessment• A life cycle assessment (LCA, also known as life cycle
analysis, ecobalance, and cradle-to-grave analysis) is a
technique to assess environmental impacts associated with
all the stages of a product's life from cradle-to-grave (i.e.,
from raw material extraction through materials processing,
manufacture, distribution, use, repair and maintenance, and
disposal or recycling). LCA’s can help avoid a narrow outlook
on environmental concerns by:
– Compiling an inventory of relevant energy and material inputs and
environmental releases;
– Evaluating the potential impacts associated with identified inputs and
releases;
– Interpreting the results to help you make a more informed decision.
http://en.wikipedia.org/wiki/Life_cycle_assessment
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Energy in LCA
• Usually treated as an input from the
technosphere
– Technosphere is an ecological term describing
the novel human techno-ecosystems that are
economically engineered systems of the total
human ecosystem (or anthrome)
• Can be analyzed as independent process(es)
for energy analysis and comparison
But…
• Energy projects typically focus on energy
balances, efficiency, and economics
• “Carbon replacement” is the only ecological
concept typically considered in energy
projects
• The broader environmental impacts of
energy decisions are complex and not usually
considered
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AtmosphereEnergy
Conversion
Decay or
burned
without
energy
conversion
Forests
Roundwood
Lumber
Pallets
Disposal
Recycling
The Carbon Cycle of Wood Pallets
Adapted from Skog and Nicholson, 2000
GrowthHarvest
CO2
CO2
AtmosphereEnergy
Conversion
Decay or
burned
without
energy
conversion
Underground
Refining
Resin/Pellets
Pallets
Recycling
The Carbon Cycle of Plastic Pallets
Drilling
Disposal
CO2
CO2
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AtmosphereEnergy
Conversion
Decay or
burned
without
energy
conversion
Underground Refining
Resin/Pellets
Pallets
Recycling
Drilling /
Forests
Roundwood
Lumber
Pallets
Harvest
What’s the difference?
Carbon +
Carbon
Neutral
Disposal
CO2
CO2
CO2
How do the different treatment methods compare?
• Comparing Heat Treatment, Me Br Fumigation and RF Heating
“Life Cycle Analysis of pallet types and treatment methods” – Ray, et al 2010
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Why bioenergy?
• Assumed benefits for:
– Climate change impact
– Solution to peak oil
– Energy security
– Local economy
The need for scientific, not political,
evaluation of energy sources
“There is no shortage of energy
anywhere on earth that has not been
caused by government.”
- Michael T. Halbouty, world-renowned
oilman and geologist
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The need for scientific, not political,
evaluation of energy sources
“In 122 years, about 3.3 million oil wells have been drilled
into the planet’s crust. Of this number, 2.5 million were
drilled in the 48 continental states of the United States…The
rest of the world has been relatively unexplored, especially
formerly colonial nations of Africa and Asia.”
- Jude Wanniski, economist and author, The Way the World
Works
U.S. Wood Energy Potential
• By 1980 USDA estimate, 600 million dry tons/year of “unused” wood
• Using standard btu conversions, this is equivalent to 1.675 billion barrels of oil
• US oil consumption is currently 7.3 billion barrels oil/year
• Nearly one quarter of our oil consumption could be eliminated by full utilization of unused woody biomass
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Pennsylvania’s Forests – 16 million acres of biological “solar
panels” storing carbon energy!
•658 million tons (55%) of our forest is in “low-use wood” (LUW); 469 million tons are
potentially available for harvest
•This volume of forest wood could yield about 6 million dry tons per year in perpetuity
300 Million 40 lb bags of
wood pellets
3 million homes
6 Million Dry Tons Per Year is
Equivalent to:
5 - 10 Wood Ethanol
Plants
480-600 million gals
ethanol
600 District Energy
Projects
475 - 500 million gallons of #2
heating oil (Karakash, 2007)
How LCA works
http://www.epa.gov/climatechange/wycd/waste/lifecycle.html
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http://www.worldchanging.com/archives/009334.html
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Questions remain:
• When is biomass energy a smart
environmental option?
• Are “environmentally correct” and
“economically correct” mutually exclusive?
• Is LCA a way to produce scientifically sound
public energy policy?
• Will LCA evolve into a world standard policy
tool?
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