Environmental Engineering Reference
In-Depth Information
11
Life-Cycle Energy
and Greenhouse Gas
Impacts of Biofuels and
Biomass Electricity
Alphonse Anderson and Gregory Keoleian
University of Michigan
contents
11.1
The Critical Role of Life-Cycle Assessment ......................................................................240
11.1.1 Introduction ..........................................................................................................240
11.1.2 Functional Unit .....................................................................................................240
11.1.3 Metrics .................................................................................................................. 241
11.1.4 Allocation Methods .............................................................................................. 241
11.1.5 Data....................................................................................................................... 243
11.1.6 System Boundaries ...............................................................................................244
11.1.7 Modeling ...............................................................................................................244
11.1.8
Life-Cycle Inventory and Impact Assessment......................................................244
11.2
Biofuels Life-Cycle Energy and GHG Emissions ..............................................................244
11.2.1 Introduction ..........................................................................................................244
11.2.2
Life-Cycle Energy ................................................................................................ 245
11.2.2.1 Ethanol .................................................................................................. 245
11.2.2.2 Biodiesel ............................................................................................... 250
11.2.2.3
Soybean Biodiesel and Renewable Gasoline ........................................ 254
11.2.3
Life-Cycle GHG Emissions .................................................................................. 255
11.2.3.1 Modeling Uncertainty ........................................................................... 255
11.2.3.2 Ethanol .................................................................................................. 256
11.2.3.3 Biodiesel ............................................................................................... 259
11.2.3.4
Soybean Biodiesel and Renewable Gasoline ........................................ 260
11.2.4
Other Biofuel Sources .......................................................................................... 261
11.2.4.1 Ethanol .................................................................................................. 261
11.2.4.2 Biodiesel ............................................................................................... 261
11.3
Biomass Electricity ............................................................................................................. 262
11.3.1 Introduction .......................................................................................................... 262
11.3.2
Life-Cycle Energy ................................................................................................ 262
11.3.2.1 Willow .................................................................................................. 262
11.3.2.2
Mixed Wood Waste .............................................................................. 265
11.3.2.3
Hybrid Poplar ........................................................................................ 266
11.3.2.4
Carbon Sequestration ............................................................................ 267
11.3.3
Life-Cycle GHG Emissions .................................................................................. 269
11.3.3.1 Willow .................................................................................................. 269
239
