CFD analysis and scale up of a baffled membrane reactor for hydrogen production by steam methane reforming

Abstract

Catalytic membrane reactor (CMR) represents an intensified process that combines the reaction and separation steps. For a high level of productivity, multiple membrane tubes are placed in a CMR, which can lead to the problem of concentration and temperature gradients. This study explores the idea of placing baffles inside the CMR, which is called baffled membrane reactor (BMR). Representative CMR and BMR are compared using computational fluid dynamics (CFD) simulations. First, the CFD model of a single-tube CMR is validated with the published experimental data. The results for a 4-tube CMR and BMR (with 14-baffles) reveal that the baffles lead to complex flow patterns, regions with elevated pressure, reduced concentration gradients and reduced temperature drops. The BMR’s performance is less sensitive to an increase in gas hourly space velocity than that of the CMR. Simulations of a larger-scale BMR shows that the performance improvement over the CMR is retained.