A non-permselective membrane reactor for chemical processes normally requiring strict stoichiometric feed rates of reactants

A novel type of membrane reactor with separated feeding of the reactants is presented for chemical processes normally requiring strict stoichiometric feed rates of premixed reactants. The reactants are fed in the reactor to the different sides of a porous membrane which is impregnated with a catalyst for a heterogeneously catalyzed reaction. If the reaction rate is fast compared to the diffusion rates of the reactants, a small reaction zone inside the membrane occurs and slip of one of the reactants to the opposing side of the membrane is prevented. The location of this reaction zone will be such that the molar fluxes of the reactants are always in stoichiometric ratio. The features of this reactor are shown by means of mathematical modelling of molecular diffusion and viscous flow combined with an instantaneous, reversible reaction inside the membrane. As a model reaction the Claus reaction was selected and by conversion measurements the principle of a shifting reaction plane inside a porous membrane is demonstrated.