Experimental Study On Carbon Dioxide Reforming Methane Catalyzed By Coke

This paper is mainly about the study of carbon dioxide reforming of methane, choosing the coal as the catalyst, and have a further research about the active component over the char. A fixed bed reactor under an atmosphere pressure has been used to study the conversion of reforming CH4 and CO2 with the char and modified coal char. The characteristics of catalysts were analyzed by TG, BET and SEM-EDX etc., and we investigated the influence of specific surface area, content and active constituent to the catalytic activity.We investigated the mechanism of carbon dioxide reforming of methane. Different catalysts has a big different mechanism in the reaction. CH4 and CO2 reforming reaction system was analyzed by the stoichiometric coefficient matrix method, it was believed that three different independent reactions of the reaction system. The results of thermodynamic analyse of CH4 and CO2 reforming reaction system indicated that CH4 and CO2 reforming reaction will react when reaction temperature is higher than 650 ℃. At the same time the higher the temperature, the easier the gasification reaction of methane cracking reaction and carbon.We chose three different coals during the experiment, and it was found that the modified char ash ingredient is the key factor, the lower the ash content, the better its catalytic. We also modified the coal with hydrochloric acid and sodium hydrate. As the result showed:the activity of the catalyst modified by hydrochloric acid is reduced, while the activity of the catalyst modified by sodium hydrate is enhanced.We added silicon dioxide and calcium oxide into the coal, which it was showed that the activity of the catalyst added by silicon dioxide is reduced, and the activity of the catalyst added by calcium oxide is enhanced. We investigated the catalytic activity of char supported Ni and adding for CH4 and CO2 reforming reaction system, comparing the activity of H2at the same conditions. Comparison of the active ingredient found in different loadings, the activity of catalyst was widely enhanced through modified Ni and Co, at the same time it can effectively suppress the carbon deposition. Then the 5%Ni-Char was selected to explore the impact on carbon dioxide reforming of methane in the process of reuse the Char. It was showed that it could still keep a high activity even if the catalyst was reused four times, and the mass loss rate of each reuse time is lower than the last. So we can say this kind of catalyst has a high activity and stability. We also investigated the activity and stability of the catalyst over different feed ratios. The results proved that it showed a big difference over different feed ratios. The larger the ratio of CH4/CO2, the lower conversion rate of CH4 and the higher conversion rate of CO2, while the mass addition of the catalyst is larger after reaction. The main reason is that the occurrence of methane pyrolysis during the carbon dioxide reforming of methane. The lower the ratio of CH4/CO2, the lower conversion rate of CO2 and the higher conversion rate of CH4, while the mass loss rate is larger after reaction. The main reason is that the occurrence of disproportionation between carbon and carbon dioxide.