Development of v-based oxygen carriers for chemical looping oxidative dehydrogenation of propane

Two different preparation methods, viz. incipient impregnation and mechanical mixing, have been used to prepare V-based oxygen carriers with different V loadings for chemical looping oxidative dehydrogenation of propane. The effect of the preparation method, V loading, and reaction temperature on the performance of these oxygen carriers have been measured and discussed. It was found that the VO_x species can be well distributed on the support when the V loading is low (5 wt.% and 10 wt.%), but they may become aggregated at higher loadings. For oxygen carriers with a higher V loading, the oxygen transport capacity of the oxygen carrier, propane conversion and CO_x selectivities increase, while the propylene selectivity decreases. With a V-loading of 10 wt.%, the maximum propylene yield was achieved. The VO_x species were better distributed over the support when applying the impregnation method; however, at higher V loadings the V-based oxygen carriers prepared by mechanical mixing showed a larger oxygen transport capacity. The oxygen carriers prepared by impregnation showed a better performance for the oxidative dehydrogenation of propane (ODHP) and re-oxidation reactions compared to oxygen carriers prepared by mechanical mixing. Higher reaction temperatures are favorable for the re-oxidation reaction, but unfavorable for the propylene production.