Effect of the orientation of a bilayer catalytic membrane on the effective conversion

The flow of a gas through a bilayer porous membrane with a surface chemical reaction in one of its layers is considered. The reaction (catalytic) layer is assumed to be finely dispersed and characterized by a Knudsen flow regime. The flow regime in the coarsely dispersed support layer is assumed to be hydrodynamic. The asymmetry of membrane catalytic properties, i.e., the dependence of the reacting gas conversion on the orientation of the membrane with respect to the flow, has been studied. The conversion in the reversible and irreversible reactions at the same reagent flow rate is shown to strongly depend on the orientation of the membrane with the possible inversion of the asymmetry effect during the reversible reaction upon a change in the system parameters.