(44j) Kinetic Modeling of CO2-Assisted Oxidative Dehydrogenation of Propane over CrOx/SiO2 Catalysts

CO₂-assisted oxidative dehydrogenation of propane (ODPC) has been proposed as an efficient process for production of propylene and CO₂ reduction due to simultaneous reaction between propane and CO₂. Participation of CO₂ as oxidant enhances the equilibrium conversion of propane by involving directly in the ODPC reaction and coupling the dehydrogenation with reverse water-gas shift (RWGS) reaction. Including the RWGS reaction, the ODPC reaction network contains multiple reactions such as direct dehydrogenation of propane, dry reforming of propane, hydrogenolysis, reverse-Boudouard reaction, and etc. Therefore, constructing the kinetic model with these multiple reactions and evaluating of their contribution are required to describe the ODPC reaction. The Mars-van Krevelen (MvK) mechanism, which contains the redox cycle of lattice oxygen, has been proposed to elucidate the mechanism of the ODPC reaction. Thus, it should be considered for constructing the rigorous kinetic model of ODPC reaction. In this work, we report a kinetic model for the ODPC reaction, based on the MvK mechanism with including the multiple reactions. Notably, estimation of kinetic parameters was conducted and the contribution of major reactions were evaluated. With this lumped kinetic model, the optimal operating condition were suggested as a kinetic point of view. For determining the optimal operating condition as a practical point of view, Global Warming Index(GWI) was introduced and calculated to evaluate the net carbon usage for fuel. Hence, the optimal operating condition as a kinetic and practical view was compared.