Performance evaluation of mass transport enhancement in novel dual-channel design of micro-reactors

Abstract

Various design configurations of semi-T-shaped dual-channel micro-reactors were numerically examined for their laminar mass transport performance in heterogeneous catalytic combustion of methane and air. One single-channel and five dual-channel configurations (i.e., parallel, divergent, convergent, zig-zag, and curved configurations) were investigated with a two-dimensional computational fluid dynamics model. These innovative design configuration were compared in terms of CH4 utilization, pressure drop, CO/CO2 ratio, catalyst utilization, and a performance index at various Reynolds numbers. Dual-channel micro-reactors were found to enhance mass transport due to the well mixed flow and the increased reaction contact area. By suitably modifying the dual-channel layout angle and shape, recirculation zones can be formed within the reactor which increase CH4 utilization. However, the improved conversion rate is achieved at the cost of high pressure drop. The parallel dual-channel design provides the highest conversion per unit pressure drop over the range of the Reynolds numbers studied. For Reynolds numbers of 20 and 40, compared to the single-channel micro-reactor, divergent, convergent and curved channel designs yield higher conversion per unit pumping power. However, further increase of Reynolds number (i.e., 60, 80, and 100) deteriorates their performance due to the significantly increased pressure drop and shorter residence time.