Jesse Daystar

Life-cycle assessment of bioethanol from pine residues via indirect biomass gasification to mixed alcohols.

Abstract The goal of this study was to estimate the greenhouse gas (GHG) emissions and fossil energy requirements from the production and use (cradle-to-grave) of bioethanol produced from the indirect gasification thermochemical conversion of loblolly pine (Pinus taeda) residues. Additional impact categories (acidification and eutrophication) were also analyzed. Of the life-cycle stages, the thermochemical fuel production and biomass growth stages resulted in the greatest environmental impact for the bioethanol product life cycle. The GHG emissions from fuel transportation and process chemicals used in the thermochemical conversion process were minor (less than 1 percent of conversion emissions). The net GHG emissions over the bioethanol life cycle, cradle-to-grave, was 74 percent less than gasoline of an equal energy content, meeting the 60 percent minimum reduction requirement of the Renewable Fuels Standard to qualify as an advanced (second generation) biofuel. Also, bioethanol had a 72 percent lower a...

Carbon Emission Reduction Impacts from Alternative Biofuels

Abstract The heightened interest in biofuels addresses the national objectives of reducing carbon emissions as well as reducing dependence on foreign fossil fuels. Using life-cycle analysis to evaluate alternative uses of wood including both products and fuels reveals a hierarchy of carbon and energy impacts characterized by their efficiency in reducing carbon emissions and/or in displacing fossil energy imports. Life-cycle comparisons are developed for biofuel feedstocks (mill and forest residuals, thinnings, and short rotation woody crops) with bioprocessing (pyrolysis, gasification, and fermentation) to produce liquid fuels and for using the feedstock for pellets and heat for drying solid wood products, all of which displace fossil fuels and fossil fuel–intensive products. Fossil carbon emissions from lignocellulosic biofuels are substantially lower than emissions from conventional gasoline. While using wood to displace fossil fuel–intensive materials (such as for steel floor joists) is much more effec...

AWARE-US: Quantifying water stress impacts of energy systems in the United States

Energy production typically consumes a large amount of fresh water, which is a critical resource for both human and ecosystem needs. Robust water impact analysis is prudent prior to deploying new energy systems at scale. While there are many water indices representing relative water availability (or scarcity), they are not suitable for analyzing the impact of consumptive water in the context of life-cycle analysis (LCA). The available water remaining (AWARE) concept, developed by the Water Use in LCA Group, enables global water impact analysis (AWARE-Global). However, while AWARE-Global enables consistent comparison internationally, it lacks the high spatial resolution and fidelity needed for decision-making at the local level regarding energy system deployment within the United States (U.S.). In this study, we developed an AWARE system for applications in the contiguous U.S. (AWARE-US) by incorporating measured runoff and human water use data at U.S. county-level resolution. Results of AWARE-US quantify the water stress and the impacts of increase in water consumption in various regions within the U.S. To demonstrate the potential use of AWARE-US, we evaluated the impacts of a potential hydrogen fuel cell electric vehicle deployment scenario on the regional water stress in various regions within the U.S.