Analysis of Nonisothermal Membrane Reactors - 1

here are many possible uses of membrane reactors to combine reaction and separation within a single processing unit. Such uses include product removal, distributed feed of a reactant and separated feed of two reactants, to name only some of the most-studied. Some niche areas where membrane reactors can make a unique contribution have been identified [Dixon, A.G., 2003]. One of these is in the control of tubular reactor temperature profiles by distributed feed of a reactant through the reactor tube wall.

Membrane reactors can be used for reactions in which the yield of an intermediate product is of interest. A typical reaction scheme is of the consecutive-parallel type:

A   +   B   ®   R          
A   +   R   ®   P   +   Q

where the reactions are parallel with respect to reactant A, and consecutive with respect to R. Many catalytic reactions of commercial importance have this structure, such as hydrocarbon partial oxidations, where A represents oxygen, B represents a hydrocarbon, R is the desired partial oxidation product and P, Q are the undesired total oxidation products (CO2 and H2O). The general behavior of membrane reactors with reactant feed (cross-flow reactors) under isothermal conditions has been studied by our group [Lu, Y., Dixon, A.G., Moser, W.R. and Ma, Y.H., 1997a, Lu, Y., Dixon, A.G., Moser, W.R. and Ma, Y.H.,1997b].