Oxidative Dehydrogenation of Ethane to Ethylene over Chromium on Zirconia Catalyst
Oxidative dehydrogenation of ethane to ethylene was investigated on ZrO2 supported Cr2O3 catalysts taking CO2 as oxidants.CO2 acts as a diluent for enhancing the equilibrium conversion of light alkanes and as an agent for the removal of coke formed on the catalyst thus acquires enormous importance. Cr2O3 on ZrO2 catalysts prepared by wet impregnation method were characterized by BET-surface area, XRD, TPR, and TPD of ethylene. The effect of Cr2O3 / ZrO2 catalyst were carried out in a fixed bed reactor in the temperature range from 550-650 °C to increase the yield of ethylene.15wt% Cr2O3/ZrO2 catalyst showed 42% ethane, 37% CO2 conversions with 36% ethylene selectivity, this catalysts showed high conversions of ethane and CO2 when compared to alumina supported chromium catalyst. In heterogeneous catalytic reactions mass transfer play a vital role in affecting the rate of a reaction. Mass transfer limitations include both the internal and external diffusion of components into and out of the catalyst. The order of reaction is considered to be One and the internal and external diffusion is studied by Weisz Prater and Mears criteria.
Keywords - Oxidative dehydrogenation, ethylene, carbon dioxide, Cr catalyst, Weisz prater criteria, Mears criteria, Diffusion