Conditioning and Detailed Analysis of Biomass Derived Fuel Gas Ongoing and Planned Work by Battelle
Gas turbine based power and cogeneration schemes are likely to become more favored as turbine efficiencies improve, but the economics of local power generation may depend on the use of low cost fuels other than natural gas. Opportunities may arise in the application of gas turbines in the pulp and paper industry and the wider use of biomass derived fuels in general. These fuels, as produced, typically contain inorganic impurities originating from ash forming substances and other minor constituents of the feedstock. Also, depending on the biomass treatment process, they contain varying amounts of complex organic derivatives, commonly referred to as tars, and some simpler condensable vapors. The Department of Energy is sponsoring work aimed at providing realistic data on low level constituents and impurities in gas derived by indirect gasification of wood, some of which may have disproportionately severe effects on turbine operation, durability, and emissions performance. It is planned to sample gas from both laboratory scale (up to 20 tons/day) and pilot scale (200 tons/day) installations and to assess the effectiveness of wet scrubbing procedures and catalytic reforming of condensables in cleaning up the gases. This paper discusses the rationale for this work, experimental approach, and analytic procedures that will be used. The work will include the operation of a small (220-kWe) gas turbine to provide direct information on the impact of using the final biomass derived gas delivered by the system. The laboratory scale work is currently under way, with a planned completion date in mid 2000. The second phase is dependent on arrangements for integration of the R&D effort with the operation of the pilot plant.