Life Cycle Assessment

Transcription

1 Charles D. Ray LIFE CYCLE ASSESSMENT FOR BIOENERGY 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. 1

2 Energy in LCA Usually treated as an input from the technosphere Technosphereis 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 2

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4 The Carbon Cycle of Wood Pallets Decay or burned without energy conversion Atmosphere Growth Forests Harvest Roundwood Lumber Pallets Energy Conversion Recycling Adapted from Skog and Nicholson, 2000 Disposal The Carbon Cycle of Plastic Pallets Atmosphere Drilling Energy Conversion Decay or burned without energy conversion Underground Refining Resin/Pellets Pallets Recycling Disposal 4

5 What s the difference? Atmosphere Drilling / Harvest Energy Conversion Decay or burned without energy conversion Carbon + Underground Carbon Forests Neutral Refining Roundwood Resin/Pellets Lumber Pallets Pallets Recycling Disposal 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

6 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 6

7 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 btuconversions, this is equivalent to 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 7

8 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 milliondry tons per year in perpetuity 6 Million Dry Tons Per Year is Equivalent to: 600 District Energy Projects 5-10 Wood Ethanol Plants million gallons of #2 heating oil (Karakash, 2007) 300 Million 40 lb bags of wood pellets 3 million homes million gals ethanol How LCA works 8

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10 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? 10

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