CURRENT HURDLES TO THE SUCCESS OF HIGH-TEMPERATURE MEMBRANE REACTORS

High-temperature catalytic processes performed using inorganic membran es have been in recent years a fast growing area of research, which se ems to have not yet reached its peak. Chemical engineers, catalysts an d materials scientists have addressed this topic from different viewpo ints in a common effort. Despite the amount of work already carried ou t, the direct application of inorganic membrane reactors in the proces s industry is still limited because of a large number of technical and economic drawbacks. The opportunities of this novel type of reactor c ompared with conventional reaction and separation systems have been em phasised in several former reviews. In the present contribution attent ion is focused on the major hurdles along the way of exploitation of t hese possibilities: high costs, low permeability, synthesis of defect- free permselective layers, instability of membranes and catalysts, sea ling of membranes into modules, etc. An assessment of what has been al ready accomplished in the attempt to overcome these limitations is giv en, stressing the gaps still to be filled and pointing the way towards future efforts to reach this goal.