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/CeO ₂/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/CeO ₂/SiO₂-catalyzed product gas whereas it was about 30, 113, and 139 g/m³ 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/SiO ₂ 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.