Ministructured catalyst bed for gas‐liquid‐solid multiphase catalytic reaction

Abstract

AbstractA ministructured reactor concept improves the performance of multiphase gas‐liquid‐solid reactions over conventional packed‐bed and trickle‐bed reactors. In the mini‐structured reactor, the catalyst bed is structured at the particle level by dividing the bed into a number of identical, parallel flow channels with the channel walls being catalyzed. The hydraulic diameter of each channel opening is from 0.2 to 2 mm, comparable to the conventional particle size. The mini‐structured reactor can be assembled using monolith catalyst modules that have been a proven material technology for gas‐phase reactions. Two types of gas‐liquid‐solid reactions, olefin hydrogenation and toluene saturation, are used to test the fundamental feasibility of the mini‐structured reactor under steady‐state reaction conditions in a cocurrent down flow mode. The new reactor shows an order of magnitude increase in the activity compared to a trickle‐bed operation for reaction conditions of practical interest. This degree of activity improvement is larger than estimates based on conventional analyses of catalyst geometric surface area and/or characteristic pore diffusion lengths. Individual catalyst particles are significantly underutilized in a trickle‐bed reactor. More ideal contacting of gas, liquid and catalyst, as well as the enhancement of overall mass‐transfer processes in the mini‐structured reactor, makes it possible to dramatically improve the gas/liquid multiphase reaction performance over solid catalysts.