Magnesium Oxide Used As Support In The Catalytic Conversion Of Methane To Synthesis Gas And Modification

The reaction of partial oxidation of methane to syngas has been one of the most promising CH4 utilization approaches, which has the advantages such as higher efficiency, mild exothermicity, high selectivity of product. But it will lead to hot-spot in catalyst bed for it is exothermic reaction and the mixture of CH4 and O2 is explosive gas, which are danger for large industrial scale. Recently, the combined partial oxidation and CO2 reforming of CH4 has been attracted atention by researchers all over the world. For it have many advantages compared to partial oxidation of CH4 and CO2 reforming of CH4. Firstly, by coupling the exothermic partial oxidation reaction with the endothermic reforming reaction. Secondly, by changing the feed composition, one can control the product ratio of H2/CO according to the need of the postprocess. Now, many researchers has been working at developing an active and stable Ni catalyst to solve the problem of carbon deposition and metal sintering, so that which can be applied in industry. The reactions were studied using fixed bed reactor. Catalysts were characterized by means of XRD, BET, H2-chemsorption, TPR, TG-DTA.For combined partial oxidation and CO2 reforming of CH4 to syngas, using super high-active magnesium oxide as catalyst support. Investigating the influence factor of loading of Ni, MgO support precursors, prepared method on catalytic activity. The result show that 15wt.% was the optimal loading of Ni, which was determined by amount Ni and metal dispersion. Different MgO supports whicn were prepared by different precursors caused different character and catalytic performance. NiO/MgOfinished product had best catalytic performance. The reason may be BET and particle size of supports were different. Catalytic performance of catalysts was direct ratio with BET and reciprocal of particle size. Catalytic performance of NiO-MgO which was prepared by coprecipitate was lower than NiO/MgO which was prepared by impregnating.For partial oxidation of methane to syngas, the Multiple support Mg-Al-O was prepared by coprecipitating. Investigating the influence factor of different proportion Mg-Al-O, different mixed method, different added promoters and different modified means on catalytic activity and anti-carbon depositinability. Acid sites and alkali sites on Surface of support could enhance activity and stability of catalyst. Different added promotes and different modified means had large effect on activity of catalyst. NiO/Mg-Al-Ce-Zr-O which Ce-Zr coprecipitate modified enhanced BET, separation of an active component and stability of support. It also reduced deoxidized temperature of active component NiO.