Catalytic Conversion of Methane and CO2 to Synthesis Gas

Abstract

Consuming two major greenhouse gases, carbon dioxide (CO2) and methane (CH4), to produce synthesis gas, which is a mixture of carbon monoxide (CO) and hydrogen (H2), carbon dioxide reforming of methane shows significant environmental and economic benefits. Recently the development of CO2 reforming of methane (Dry reforming) has been investigated to produce syngas. Even though steam reforming of methane is widely industrialized to produce syngas (a mixture of H2 and CO), lower ratios are needed for oxo- and Fischer–Tropsch synthesis. Carbon dioxide reforming of methane 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, two major greenhouse gases. However, the process has not found wide industrial application due to severe catalyst deactivation, basically caused by carbon formation. Therefore, it is of great interest to develop stable catalysts without severe deactivation. This work is mainly focused on the development of base metal like nickel-based catalysts to achieve stable operation for CO2 reforming of CH4. The Nickel (Ni)- catalyst prepared by impregnation method using support g-Al2O3 and different types of promoters (CeO2,ZrO2, K2O and MgO) to improve activity, stability and selectivity in order to reduce coke formation and to achieve long-term operation. Nickel catalysts promoted by the CeO2 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/g-Al2O3 catalysts shows good activity, stability and long-term operation as compared to the unpromoted catalysts. It reduces the deactivation rate.The catalysts were characterized by the Xray Diffraction Method and BET Method suggests types and nature of crystalline phases present, degree of crystallinity, amount of amorphous content, orientation of crystallites, BET Surface Area ,Pore Volume , Pore Diameter over different Catalysts.