(585e) Solar Thermal Conversion of Biomass for Synfuel Production

Aerosol steam gasification and water-free pyrolysis of biomass components was conducted at temperatures achievable using solar thermal energy (>1000 °C). Gasification and pyrolysis of cellulose and lignin were performed using an electrically heated tube furnace to simulate the solar source. High conversions of biomass to syngas (>98%) were found for temperatures exceeding 1100 °C, while significantly lower conversions (< 65%) were obtained at temperatures less than 1000 °C. The low temperature experiments showed a large number of side products, leading to the conclusion that gasification should be conducted at as high a temperature as possible. These results were verified ?on-sun? at the National Renewable Energy Laboratory, showing that high yields of syngas could be obtained in short residence times (<2 s) using a solar thermal source. Gasification of a naturally occurring biomass product (Poa pratensis, Kentucky bluegrass) showed similar results, with very high yields of syngas in the solar reactor. An economic analysis of hydrogen production by this method was conducted and yielded a selling price of $0.95 - $1.30 / kg H2. This is significantly lower than the conventional price of fossil fuel derived hydrogen.