SYNTHESIS GAS-FORMATION BY CATALYTIC-OXIDATION OF METHANE IN FLUIDIZED-BED REACTORS

The production of synthesis gas (CO + H-2) by the catalytic partial oxidation of CH4 in air or O2 in static fluidized beds at atmospheric pressure has been examined over Pt, Rh, and Ni catalysts coated on 100-mum alpha-Al2O3 beads. With CH4/air feeds, CO and H-2 selectivities as high as 95% with >90% CH4 conversion were obtained on Rh and Ni catalysts at contact times of 0.1-0.5 sec. Pt catalysts were found to have significantly lower selectivities and conversions, which may be due to more H2O forming reactions or the slow steam reforming behavior of Pt. The optimal selectivities for all the three catalysts were improved by heating the reaction mixture above the autothermal reactor temperature and using O2 instead of air. The selectivities and conversions were fairly constant over the range of contact times used. Probable reaction pathways for CH4 oxidation in fluidized beds are discussed. (C) 1994 Academic Press, Inc.