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A study of the catalytic membrane contactor operated in pore-flow-through (PFT) mode was carried out for hydrogenation of α-methylstyrene (AMS) to cumene over palladium as a test reaction. By applying a metalorganic chemical vapour deposition method, the catalyst was deposited as nanoparticles on the pore walls of porous alumina capillaries. Experiments were performed with up to six individual Pd-activated capillaries in a laboratory-scale reactor set-up and with capillary bundles in a small pilot plant. The influence of the operating parameters on the reactor performance such as temperature (303–333 K), hydrogen pressure (5–10 bar), transmembrane flux (up to 200 l·m−2·min−1), pore size of the capillaries (0.6–3.0 µm) and concentration of AMS in n-heptane used as solvent was investigated. Moreover, the performance of the PFT-system was compared to that of conventional reactors (e.g. fixed bed, trickle bed, bubble column, stirred tank) and novel reactor designs (catalytic membrane contactor in diffuser mode, monolith reactor) based on published data. It is shown that the PFT principle enables very high activity, comparable with a suspended powder catalyst in a stirred tank reactor and, at the same time, an excellent space time yield. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Two consecutive model reactions of the type A - B→ C are studied in two kinds of catalytic membrane reactors. The partial oxidation of methane to synthesis gas due to CH 4 + 1/ 2 0 2 → CO + 2H 2 was investigated in a novel type of permselective membrane reactor using perovskite hollow fibers for the selective separation of oxygen from air. Partial hydrogenations were studied in a pore-through-flow membrane reactor as a special type of a catalytic membrane contactor. The catalytically functionalized pores of the membrane provide a medium with defined contact times for the cofeed of hydrogen and an unsaturated hydrocarbon, and the attempts of the scale-up of the successful laboratory experiments to the pilot scale are reported.

The hydrogenation of α-methylstyrene (AMS) was carried out in a flow-through membrane reactor at: 45-50°C, 1-40 bar, and 18 vol % AMS in heptane. An α-Al 2 O 3 membrane tube of defined pore size was used as catalyst support material. A wet impregnation method was used to prepare the active membrane with palladium as catalyst. Experiments with a spherical Pd/Al 2 O 3 egg-shell catalyst in a slurry reactor were carried out under similar reaction conditions for comparison. Results from the flow-through membrane reactor were also compared to results from other types of reactors described in the literature. Application of the flow-through membrane reactor exhibits an enhanced performance with respect to the productivity (reaction rate per mass of palladium) relative to that of other types of membrane reactors and other conventional reactors, such as a slurry reactor, a trickle-bed reactor, and a bubble-column reactor.