No abstract

Direct epoxidation of propene with hydrogen peroxide vapor was conducted in a microstructured reactor containing TS-1 catalyst coatings. At 140 °C, 1 bar, 5 vol % hydrogen peroxide, and 15 vol % propene, productivities of more than 1 kg of propene oxide per kg of catalyst and hour are obtained in lab scale, which is in an industrially highly relevant range. Excellent selectivities to propene oxide based on propene of >90% were reached. Potential and need for improvement lie in the propylene oxide selectivity based on hydrogen peroxide, which was observed to be about 25%. By increasing the molar excess of propene to about 6.6, propylene oxide selectivities related to hydrogen peroxide of up to 60% have been observed in the pilot plant.

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 CH₄ + ½O₂ -> CO + 2H₂ 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. © 2007 American Chemical Society [accessed 2013 November 26th