Evaluation of porous catalytic membranes operated in pore-flow-through mode for hydrogenation of α-methylstyrene

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.