Improvement of active site accessibility of resin catalysts by polymer/carrier composites: development and characterisation of monolithic catalytic chromatographic reactors

Abstract

Synthetic resins are one of the most used catalysts in the production of additives for gasoline fuelled cars. Ethers like MTBE (methyl- t-butylether), TAME ( t-amylmethylether) or ETBE (ethyl- t-butylether) are now widely used to enhance the anti-knock performance of the fuels. Now more than 14,000,000 t per year of the above-mentioned ethers are produced world-wide. On the other hand there is much less use of catalytic ion exchange resins in the production of fine chemicals. Reasons might be selectivity aspects, the availability of resins in a shape which is well suited for technical reactors and a lack of knowledge with respect to the accessibility and stability of the active sites. In this study the preparation and characterisation of polymer/carrier composite components for catalytic applications is described. Monolithic rods for chemical reactions with simultaneous separation were prepared by a precipitation polymerisation process and investigated. The distribution of the cross-linker concentration across the particle radius is calculated based on co-polymerisation parameters and discussed. The active sites are sulfonic acid groups. The distribution of the active sites was measured by scanning electron microscopy. For the cyclisation reaction of 1,4-butanediol to tetrahydrofuran and water the application of rods as a monolithic chemical reactor was demonstrated.