Biomass gasification with air in fluidized bed. Hot gas cleanup with selected commercial and full-size nickel-based catalysts

Three selected commercial, full-size steam-reforming catalysts for naphthas, BASF Gl-50, lCI 46-1, and Topsoe R-67, are tested at pilot-scale level for hot gas cleanup in biomass gasification in a fluidized bed. Gas composition and tar content in the flue gas are measured before and after the catalytic bed. Variations of the catalytic bed in H-2, CO, CO2, CH4, and H2O contents are reported for different operating conditions. Tar conversions and an apparent first-order kinetics constant for the overall tar removal reaction are-calculated. Tar contents at the exit of the catalytic reactor as low as 10 mg/m(n)(3) are obtained in a test of 50 h-on-stream without noticeable catalyst deactivation. Important variations in tar conversion with space time in the catalytic bed, with H2O/C-* in the flue gas, and with the equivalence ratio in the upstream gasifier are observed. These results obtained at the pilot-scale level and with the use of full-sized commercial catalysts are an important forward step in demonstrating the technical feasibility of the overall biomass gasification process.