A CFD study on H2-permeable membrane reactor for methane CO2 reforming: Effect of catalyst bed volume

A 2D axisymmetric model is developed for a H-2-permeable membrane reactor for methane CO2 reforming. The effect of catalyst bed volume on CH4 conversion and H-2 permeation rate is investigated. The simulation results indicate that catalyst bed volume with a shell radius of 9 mm is optimal for a tubular Vycor glass membrane with a diameter of 10 mm and H-2 permeance of 2x10(-6) mol/m(2)/Pa/s. The concentration polarization at the retentate side and the accumulation of H-2 at permeate side make it hard to extract the H-2 production at the zone far from the membrane surface. Though increasing pressure at the retentate side enhances H-2 permeation, CH4 conversion is even decreased due to unfavorable thermodynamics. And increasing sweep gas flow rate at permeate side benefits to both CH4 conversion and H-2 permeation. This work highlights the importance of determining the optimal catalyst bed volume to match the membrane in the design of membrane reactors. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Optimizing the catalyst bed volume is crucial for designing membrane reactors. Concentration polarization and gas accumulation are key factors affecting H-2 extraction. Adjusting pressure and gas flow rate can improve both CH4 conversion and H-2 permeation rates.