Defining conditions where the use of porous membrane reactors can be justified solely on the basis of improved yield

Abstract

Dehydrogenation using a porous membrane reactor is evaluated by comparing optimized membrane reactor yields to yields from a plug-flow reactor network for cases where a pressure differential is applied across the membrane. The plug-flow reactor network is equal in size to the membrane reactor. It uses the same amount of ractant paraffin at the same pressure as the membrane reactor. It uses no more inert diluent than the membrane reactor, and at the same pressure. Finally, the plug-flow reactor network produces two product streams at the same pressures as the membrane reactor and with the same fraction of the total hydrocarbon in each stream. Simple forms of the kinetic and reactor design relationships, which have been demonstrated to provide an accurate description of experimental dehydrogenation results, are used to model the two processes. A porous membrane reactor process offers a better yield than the plug-flow reactor network only at lower conversions. In this regime a substantial fraction of the total hydrocarbons is recovered from the low pressure, sweep side of the process. In all comparisons the membrane reactor is optimized only for maximum yield.