Kinetic analysis of chemical looping oxidative propane dehydrogenation at relatively low temperature

Abstract

Chemical looping oxidative propane dehydrogenation (CL‐ODH) as a potentially efficient strategy for propylene production is determined by the gas–solid reaction kinetics. This article describes a macroscopic kinetic model for CL‐ODH over the VCeAl oxygen carrier. Specifically, a comprehensive kinetic model is established to quantify the concurrent pathways of lattice oxygen‐mediated ODH and the catalytic propane dehydrogenation (PDH) over reduced sites as a function of solid conversion. At relatively low temperatures (470–515°C), CL‐ODH gradually evolves from ODH to stable PDH, while ODH has a relatively low activation energy than PDH. It is found that a lower temperature can result in a higher ratio of ODH in comparison with PDH, while higher propane pressure accelerates lattice oxygen depletion and shifts the reaction toward the PDH regime. The macro‐kinetic model could facilitate the industrial scale‐up of CL‐ODH processes.