Simultaneous production of styrene and cyclohexane in an integrated membrane reactor

A rigorous heterogeneous model is used to study the performance of the membrane catalytic reactor for the dehydrogenation of ethylbenzene to styrene. The mathematical model is extended to simulate a novel hybrid configuration which is composed of two catalytic sections separated by hydrogen selective composite membrane for hydrogen separation. One side of the reactor is a dehydrogenation section in which ethylbenzene is dehydrogenated to styrene, while the other catalytic side is a hydrogenation section in which benzene is catalytically converted to cyclohexane. The continuous removal of hydrogen from the dehydrogenation section leads to the shift of equilibrium conversion in this section, thus higher styrene yield is obtained. Detailed parametric investigation has been carried out for the membrane reactor and the hybrid reactor configurations. The effect of co-current and counter-current flow pattern is investigated. Superior performance in terms of ethylbenzene conversion enhancement far above the equilibrium value was observed in the hybrid reactor configuration. The selectivity and styrene yield considerably exceed the industrial values.