Production of Synthesis Gas by Carbon Dioxide Reforming of Methane over Nickel based and Perovskite Catalysts

Abstract

Abstract CO2 reforming of methane shows significant environmental and economic benefits by consuming two major greenhouse gases, carbon dioxide (CO2) and methane (CH4) to produce synthesis gas (CO+H2). It offers advantages such as the production of syngas with a lower H2/CO ratio and it obviates a water vaporization step to produce steam, an energy consumer process and eliminate CH4 and CO2. However, during process significant catalyst deactivation due to carbon formation takes place. Therefore, it is of great interest to develop catalysts which pose high stability without severe deactivation. This paper is mainly focused on the development of base metal like nickel-based catalyst by impregnation and perovksites by sol gel (SG) and coprecipitation (CP) method for CO2 reforming of CH4. The catalysts were characterized by the XRD and BET. The Nickel catalyst prepared by impregnation method using support -Al2O3 and different types of promoters to improve activity, stability and selectivity in order to reduce coke formation and to achieve long-term operation. Nickel catalysts promoted by the ZrO2 shows higher dispersion of the metal particle on the surface of the support than the unpromoted catalysts. It has been found that the ZrO2, CeO2, K2O and MgO promoted 10% Ni/-Al2O3 catalysts exhibited good activity, stability and long-term operation as compared to the unpromoted catalysts. It reduces the deactivation rate. The use of perovskite like oxides ABO3 has increased recently for carbon dioxide reforming of methane. Conversion of CH4 and CO2 were found in the order: LaNiO3(CP)> 10%Ni/ZrO2- -Al2O3 > LaNiO3(SG) >10%Ni/K2O - -Al2O3 > 10%Ni/MgO - -Al2O3 > LaCoO3(CP) > LaCoO3(SG) > 10%Ni/CeO2 - -Al2O3 > 10%Ni/-Al2O3 > 5%Ni/-Al2O3 > 20%Ni/-Al2O3. LaNiO3 (CP) gave high activity and stability due to further reduction of B-site cations which remain distributed in the structure and form well dispersed and stable metal particle catalysts which improved the stability and activity.