Preparation of novel helical liquid-bridge flow structured catalyst and its catalytic performance in the hydrogenation of 2-ethyl-anthraquinone

Abstract

Structured catalytic technology, one of the most promising reaction process intensification technologies, dilutes the borderline between the reactor and the catalyst in the traditional concept, and can effectively improve the problems of low catalyst utilization and low reaction selectivity caused by uneven gas-liquid distribution. To further improve the gas-liquid distribution in the reactor, a novel helical liquid-bridge flow structured catalyst with binding liquid flow ability was prepared. The effects of slurry properties (binder concentration, pH, and γ-Al2O3 content) on the quality of γ-Al2O3 washcoat were studied. The results show that γ-Al2O3 coating has the best adhesion at PVA = 5 %, pH = 3.0, γ-Al2O3 = 17.5 %. Then, washcoating of γ-Al2O3 under the optimized preparation conditions, followed by the impregnation of palladium, was applied to prepare the Pd/γ-Al2O3 catalyst on the helical string. The structured catalyst performance was tested in a laboratory-scale reactor by the hydrogenation of 2-ethyl-anthraquinone, where the impact of the hydraulic characteristics and structure properties along the structured catalysts have been especially discussed. This study reveals that the liquid flow has a great influence on the performance of the structured catalyst, which determines the contact between the liquid phase and the catalyst, and a favorable contact performance between catalyst and liquid in the reactor is essential to obtain a good catalytic performance. The novel helical liquid-bridge flow structured catalyst has excellent reaction selectivity with the condition of a stable liquid film, which has great significance to the design and development of falling film structured internals in the future.