Catalytic Membrane Reactors

Abstract

Membrane reactors combining reaction and membrane separation provide numerous advantages over conventional reactors, including retaining expensive catalysts, in situ purification, enhancing reaction rate, and reducing postprocessing of the reaction (by) products. In this article, two different ways were used to classify the various types of membrane reactors. One is based on whether the membrane is catalytic or noncatalytic, selective or nonselective, and whether or not a packed bed or a fluidized bed of catalysts is being used. The second classification is based on the membrane role: the extractor‐type, the distributor‐type, and the contactor‐type membrane reactors. This article presents the key features of these three types of reactors and the various classes of reactions these reactors have been applied, with emphasis on conventional (i.e., nonbiochemical) reaction systems.

Direct Conversion of Methane to C2Hydrocarbons in Solid-State Membrane Reactors at High Temperatures

“…In Figure a and c, the reactant O 2– is supplied through the membrane to the reactant CH 4 to form the C 2 product. The main benefits are the exclusion of unwanted reactants such as N 2 from air and the homogeneous distribution of the reactant O 2– to the catalytic reaction under ideal conditions (such as temperature), avoiding undesired side reactions. − So, the option of using selectively permeated membranes to provide the oxygen needed for CH 4 activation has many economic and environmental conveniences over the direct use of air as an oxidizer. The membrane, being impermeable to nitrogen, supplies molecular grade oxygen for the reactions, preventing the formation of NO x . − …”

“…H 2 might be a desired product or an undesired byproduct. Major advantages are the shift of the reaction equilibrium to the product side, the prevention of undesired side reactions, and the lack of additional cleaning steps. − …”

Experimental Investigation of the Application of Ionic Liquids to Methanol Synthesis in Membrane Reactors

“…Several prior studies report the use of MR for MeS to increase the conversion rate and thermal efficiency. − Galucci et al, for example, investigated a packed-bed membrane reactor (PBMR) for MeS using a commercial Cu–Zn catalyst and a zeolite-A membrane. For similar reactor conversions, the PBMR showed higher selectivity than the conventional PBR, which was attributed to the selective removal of H 2 O and CH 3 OH by the membrane.…”

Techno-Economic Analysis of an Intensified Integrated Gasification Combined Cycle (IGCC) Power Plant Featuring a Combined Membrane Reactor - Adsorptive Reactor (MR-AR) System

“…The benefit of the combined MR-AR system is that it allows for both of the ultimate reaction products (H 2 and CO 2 ) to be removed, whereas the stand-alone MR and sorption-enhanced, PSA-based AR technologies , for hydrogen production found in the literature only allow H 2 or CO 2 separation, respectively. In the combined system, performance is improved due to the significant interaction and synergy that is present between the two individual units.…”