Recent Research in Catalytic Inorganic Membrane Reactors

Abstract

The two most important, and often the most expensive, steps in a chemical process are usually the chemical reactor and the separation of the product stream. Both the process economics and the efficient use of natural resources could be improved by the combination of these two operations into a single unit operation, leading to potential savings in energy and reactant consumption and reduced by-product formation. One promising way to accomplish this combination is the use of membrane separation and catalytic reaction together in a multifunctional reactor. Until relatively recently, the use of membranes was restricted to low temperature processes with mild chemical environments, which could be tolerated by polymeric materials. Recent advances in inorganic materials have expanded the range of membrane use, to include high temperature and chemically harsh environments. This has allowed inorganic membranes to be integrated into catalytic reactors. This area was reviewed previously by the present author (Dixon, 1999). The present contribution seeks to review literature and new developments in the succeeding four and a half year period, since the end of 1998. Research directions that were previously considered promising are re-evaluated here, and new ideas since then are presented.