Three-dimensional numerical modeling on high pressure membrane reactors for high temperature water-gas shift reaction

•3-D numerical modeling on H2 production via water-gas shift reaction in membrane reactor.•Limiting CO conversion and H2 recovery resulted as the membrane permeance gets higher.•Limiting CO conversion and H2 recovery can be found as the sweep gas flow rate increases.•Reactor performance degraded with increased CO2 content in syngas.•For N2-contained syngas, reactor performance is controlled by the CO2 content.

This study presents a three-dimensional numerical model that simulates the H2 production from coal-derived syngas via a water-gas shift reaction in membrane reactors. The reactor was operated at a temperature of 900 °C, the typical syngas temperature at gasifier exit. The effects of membrane permeance, syngas composition, reactant residence time, sweep gas flow rate and steam-to-carbon (S/C) ratio on reactor performance were examined. Using CO conversion and H2 recovery to characterize the reactor performance, it was found that the reactor performance can be enhanced using higher sweep gas flow rate, membrane permeance and S/C ratio. However, CO conversion and H2 recovery limiting values were found when these parameters were further increased. The numerical results also indicated that the reactor performance degraded with increasing CO2 content in the syngas composition.