Abstract:
The reforming of methane with carbon dioxide has been proposed to produce the synthesis gas instead of steam reforming. It provides a suitable H2/CO product ratio for the methanol production. Because carbon dioxide creating Green house eflect is consumed in this process therefore, this reaction benefits to givc theenvironment. 'The objective of this research work was to study the effect of ceria loading and the effcct of calcination temperature on the reaction. All catalysts were prepared by deposition method. The catalyst was characterized by chemisorption tcclmique in ordcr to examine the activity of catalyst. The reforming reaction has been operated at atmospheric pressure, 600 OC on alumina supported palladium catalyst in packed bcd reactor. The product gas composition, H2/C0 product ratio and the deposited carbon were also observed. Since CHJCO2 reforming reaction substantially produces coke or carbon deposits on palladium, the activity of catalyst reduces as reaction proceeds. Because a oxygenin structure of ceria could react with the deposited carbon, this decreased the catalyst deactivation. Therefore, the ceria promoted catalyst is more stable than unpromoted catalyst. According to the experimental results the suitable amount of ceria loading is 8 percent Ce02. The 1 percent Pdl 8 percent Ce02J A1203 catalyst can maintain the H2/C0 product ratio about 1 throughout the reaction time. High calcination temperature provides larger size of ceria crystal. The catalyst prepared at lower calcination temperature, 600 OC, provides higher percent conversion of methane and H2/C0 ratio about 1. For the CH4/C02 reforming reaction, the suitable amount of ceria loading and calcination temperature in the PdJCeO2/Al2O3 catalyst preparation is 8 percent CeOz and 600 "C, respectively.