SUMMARYThe U.S. Department of Energy and the National Renewable Energy Laboratory are developing technologies to produce hydrogen from renewable, sustainable sources. A cost goal of $2.00-$3:00 kg À1 of hydrogen has been identified as the range at which delivered hydrogen becomes cost competitive with gasoline for passenger vehicles. Electrolysis of water is a standard commercial technology for producing hydrogen. Using wind and solar resources to produce the electricity for the process creates a renewable system. Biomass-to-hydrogen processes, including gasification, pyrolysis, and fermentation, are less well-developed technologies. These processes offer the possibility of producing hydrogen from energy crops and from biomass materials such as forest residue and municipal sewage. Solar energy can be used to produce hydrogen from water and biomass by several conversion pathways. Concentrated solar energy can generate high temperatures at which thermochemical reactions can be used to split water. Photoelectrochemical water splitting and photobiology are long-term options for producing hydrogen from water using solar energy. All these technologies are in the development stage.

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Pyrolysis of lignocellulosic biomass and reforming of the pyroligneous oils are being studied as a strategy for producing hydrogen. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. We propose a regionalized system of hydrogen production, where small- and medium-sized pyrolysis units (<500 Mg/day) provide bio-oil to a central reforming unit to be catalytically converted to H2 and CO2. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. In addition, screening tests aimed at catalytic reforming of model compounds to hydrogen using Ni-based catalysts have achieved essentially complete conversion to H2. Existing data on the catalytic reforming of oxygenates have been studied to guide catalyst selection. A process diagram for the pyrolysis and reforming operations is discussed, as are initial production cost estimates. A window of opportunity clearly exists if the bio-oil is first refined to yield valuable oxygenates so that only a residual fraction is used for hydrogen production.

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Prepared under Task No. BP911030 Excluding the consumption of fossil fuels by the power plant, the external energy efficiency and external energy ratio indicate that upstream processes are large consumers of energy. In fact, two operations, those related to flue gas clean-up and coal transportation, account for between 3.8% and 4.2% of the total system energy consumption, and between 67.4% and 70.5% of the non-coal energy. Processes involved in the gas clean-up operations include the production, transport, and use of limestone and lime in the Average and NSPS systems, and the production, distribution, and combustion of natural gas in the LEBS system. These operations consume between 35.3% and 38.5% of the non-coal energy, and between 2.0% and 2.4% of the total energy of the systems. Transportation of the coal uses similar amounts: between 30.1% and 32.2% of non-coal, and 1.8% of total system energy. As expected, the amount of resources consumed, emissions produced, and energy used, are small for the mine mouth transportation case. It was found that the transportation distance has a significant effect on the oil consumption, a few of the systems emissions, and the energy consumption, whereas the mode of transportation has virtually no effect on the results. Although energy consumption is significant, transportation required fewer resources and had lower air, water, and solid waste emissions than either the mining or electricity generation subsystems. Appendices Appendix A: Graphical Representation of the LCA System in TEAM ® Appendix B: Additional Results Tables Appendix C: Additional Figures Units of Measure Metric units of measure are used in this report. Therefore, material consumption is reported in units based on the gram (e.g., kilogram or megagram), energy consumption based on the joule (e.g., kilojoule or megajoule), and distance based on the meter (e.g., kilometer). When it can contribute to the understanding of the analysis, the English system equivalent is stated in parenthesis. The metric units used for each parameter are given below, with the corresponding conversion to English units. Mass: kilogram (kg) = 2.205 pounds megagram (Mg) = metric tonne (T) = 1 x 10 g = 1.102 ton (t) 6 Distance: kilometer (km) = 0.62 mile = 3,281 feet Area: hectare (ha) = 10,000 m = 2.47 acres 2 Volume: cubic meter (m) = 264.17 gallons 3 Pressure: kilopascals (kPa) = 0.145 pounds per square inch Energy: gigajoule (GJ) = 0.9488 MMBtu (million Btu) kilowatt-hour (kWh) = 3,414.7 Btu gigawatt-hour (GWh) = 3.4 x 10 Btu 9

Projected life cycle greenhouse gas (GHG) emissions and net energy value (NEV) of high-ethanol blend fuel (E85) used to propel a passenger car in the United States are evaluated using attributional life cycle assessment. Input data represent national-average conditions projected to 2022 for ethanol produced from corn grain, corn stover, wheat straw, switchgrass, and forest residues. Three conversion technologies are assessed: advanced dry mill (corn grain), biochemical (switchgrass, corn stover, wheat straw), and thermochemical (forest residues). A reference case is compared against results from Monte Carlo uncertainty analysis. For this case, one kilometer traveled on E85 from the feedstock-to-ethanol pathways evaluated has 43%-57% lower GHG emissions than a car operated on conventional U.S. gasoline (base year 2005). Differences in NEV cluster by conversion technology rather than by feedstock. The reference case estimates of GHG and NEV skew to the tails of the estimated frequency distributions. Though not as optimistic as the reference case, the projected median GHG and NEV for all feedstock-to-E85 pathways evaluated offer significant improvement over conventional U.S. gasoline. Sensitivity analysis suggests that inputs to the feedstock production phase are the most influential parameters for GHG and NEV. Results from this study can be used to help focus research and development efforts.

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