A comparison of Rh/CeO2/SiO2 catalysts with steam reforming catalysts, dolomite and inert materials as bed materials in low throughput fluidized bed gasification systems

The gasification of cedar wood in the presence of Rh/CeO2/SiO2 has been conducted in the laboratory scale fluidized bed reactor using air as a gasifying agent at low temperatures (823-973 K) in order to produce high-quality fuel gas for gas turbine for power generation. The performance of the Rh/CeO2/SiO2 catalyst has been compared with conventional catalysts such as commercial steam reforming catalyst G-91, dolomite and noncatalyst systems by measurements of the cold gas efficiency, tar concentration, carbon conversion to gas and gas composition. The tar concentration was completely negligible in the Rh/CeO2/SiO2-catalyzed product gas whereas it was about 30, 113, and 139 g/m(3) in G-91, dolomite and noncatalyzed product gas, respectively. Since the carbon conversion to useful gas such as CO, H-2, and CH4 are much higher on Rh/CeO2/SiO2 catalyst than others at 873 K, the cold gas efficiency is much higher (71%) in this case than others. The hydrogen content in the product gas is much higher ( > 24 vol%) than the specified level ( > 10 vol%) for efficient combustion in the gas turbine engine. The char and coke formation is also very low on Rh/CeO2/SiO2 catalyst than on the conventional catalysts. Although the catalyst surface area was slightly decreased after using the same catalyst in at least 20 experiments, the deactivation problem was not severe. (C) 2003 Elsevier Ltd. All rights reserved.