Catalysis with membranes or catalytic membranes?

This paper considers the application of inorganic membranes in conjunction with catalysis and discusses attempts which have been made to affect changes in the yields and product distributions in a number of catalytic reactions with a number of different conformations of catalyst and membrane. Various possible reactor conformations are first considered and then some results obtained for catalytically-active perm-selective membranes are presented to illustrate some of the problems encountered with such membranes. The use of non-perm-selective wall-and-tube reactors is then considered. Finally, the results of model calculations are presented which show that the most promising confirmation for the use of perm-selective membranes is one in which the membrane and catalyst are in separate units and external recirculation of reactants and products is carried out.