Modeling and comprehensive analysis of hydrogen production in a newly designed steam methane reformer with membrane system

The use of a hydrogen perm-selective membrane in the conventional steam methane reformer (SMR) is a promising technology for producing ultra-pure hydrogen under moderate operating conditions. A detailed computational fluid dynamics (CFD) analysis is performed on a membrane SMR unit for an on-site hydrogen refueling station (HRS) to get the optimum operating conditions. The developed model was validated with experimental results. The obtained results predicted that the high temperature of the process gas inlet, the high operating pressure, and the low gas hourly space velocity (GHSV) were advantageous. However, these factors must be carefully adjusted to achieve optimal efficiency. Furthermore, the simulation with a counter-current sweep gas flow configuration gave better results than a co-current operation. The estimated optimal conditions for improved CH4 conversion and H2 recovery were 4500 h-1 GHSV, 500 K inlet temperature, and the 8.5 bar operating pressure, representing CH4 conversion and H2 recovery of approximately 94.7% and 95.8%, respectively.