Thermographical observation of catalyst bed temperature in oxidative steam reforming of methane over Ni supported on α-alumina granules:: Effect of Ni precursors

Catalyst bed temperature during the oxidative steam reforming of methane over (alpha-Al2O3-supported Ni catalysts, prepared from three different precursors (nickel nitrate, nickel acetate and nickel chloride), was studied with infrared thermograph at 1073 K. It was found that the temperature near the catalyst bed inlet increased with decreasing W/F (contact time W/F: W (g): catalyst weight, F (mol/h): total flow rate of the introduced gases) in oxidative steam reforming of methane. It is thought that the bed temperature profile is influenced by the catalytic activities of methane combustion and reforming reactions. However, in the case of Ni/alpha Al2O3, it was intriguing to find that the highest bed temperature was not so influenced by the metal loading, dispersion and preparation method. The reason for this interesting result is because the catalyst with higher combustion activity has higher reforming activity. Consequently, higher temperature, which is caused by high combustion activity, is compensated to the similar level by means of endothermic reforming. (c) 2005 Elsevier B.V. All rights reserved.