(324c) Controlling Homogeneous/Heterogeneous Reactions in Alkane Dehydrogenation

Heterogeneous reactions at sufficiently high temperatures, such as in the hydrocarbon conversion, are commonly accompanied by homogeneous reactions. The homogeneous reactions follow a radical mechanism, which typically has a low selectivity and results in low yield of products. One way to suppress the low selectivity homogeneous reactions is through localized heating, for example using a microwave reactor. Development of a strategy to control the homogeneous/heterogeneous reactions can guide improvement of the process.

In this talk, we use propane dehydrogenation over Ga-alumina based catalyst as a model reaction to compare the conversion and selectivity of localized heated reactor vs. a conventional reactor. We use a coprecipitation method to prepare the Ga–doped alumina catalyst, which shows great reactivity and stability thanks to the synergy between Ga and Al atoms. XRD and Al27 NMR characterization of the catalyst shows incorporation of Ga atoms into the bulk of Al2O3 and occupied the tetrahedral Al sites, which shows a strong correlation with Ga-alumina activity. We also present a combined parametric experimental study and computational fluidic dynamics simulation to discuss the influence of temperature, flow rate, packing density, and reactor size on homogeneous/heterogeneous reactions. We extend our validated computational model for scale-up and provide insights into optimized operation.