Life Cycle Assessment of Biobutanol From Miscanthus and Sorghum Feed Stocks.

Abstract

The world faces an energy crisis since the demand for fossil fuels such as coal, oil, natural gas, is growing in most countries in the world. Meanwhile, concerns over the adverse effects of fossil fuel use on the environment and public health and its contribution to global warming are growing. In this context, biomass crops have great potential to displace fossil fuel to lower net greenhouse emissions, and to diversify the agroecosystems. Biobutanol, butanol produced from biomass, has a higher energy density than ethanol and thus would be a more advantageous fuel to substitute gasoline. The purpose of this study is to estimate the life cycle energy and butanol yield of the biobutanol production process, by examining the effects of nutrients and enzymes used in the process. This study employs the use of the full life cycle model GREET 1 2011 (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) developed at Argonne National Laboratory (U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy). After we had obtained the results of the butanol production process based on the GREET model, we compared the butanol yield for different feedstocks, forage sorghum, and miscanthus while altering the nutrients and enzymes used for production. We predict that the various feedstocks, nutrients, and enzymes will affect the butanol yield in the well-to-wheel analysis of butanol production.