Gas–Liquid Mass Transfer Intensification for Selective Alkyne Semi-Hydrogenation with an Advanced Elastic Catalytic Foam-Bed Reactor

Abstract

The Elastic Catalytic Foam-bed Reactor (EcFR) technology was used to enhance a model catalytic hydrogenation reaction by improving gas–liquid mass transfer. This advanced technology is based on a column packed with a commercial elastomeric polyurethane open-cell foam, which also acts as a catalyst support. A simple and efficient crankshaft-inspired system applied in situ compression/relaxation movements to the foam bed. For the first time, the catalytic support parameters (i.e., porosity, tortuosity, characteristic length, etc.) underwent cyclic and controlled changes over time. These dynamic cycles have made it possible to intensify the transfer of gas to liquid at a constant energy level. The application chosen was the selective hydrogenation of phenylacetylene to styrene in an alcoholic solution using a palladium-based catalyst under hydrogen bubble conditions. The conversion observed with this EcFR at 1 Hz as cycle frequency was compared with that observed with a conventional Fixed Catalytic Foam-bed Reactor (FcFR).