Optimizing Hydrogen Production and CO₂ Utilization: A Comparative Study of Steam and Hybrid Reforming in Membrane Reactors

Reducing greenhouse gas emissions is a global priority, and hydrogen is increasingly recognized as a clean fuel because its utilization produces no direct emissions. Although renewable-based hydrogen production technologies are advancing, steam methane reforming remains the dominant industrial method due to its maturity and economic advantages. Hybrid reforming, which integrates the advantages of both steam and dry reforming, provides a promising alternative for more efficient and sustainable hydrogen production. A two-dimensional axisymmetric hybrid catalytic membrane reactor model was developed for hydrogen production from natural gas, combining a Pd–Ru metallic membrane and a carbonate dual-phase membrane with Ni/Al₂O₃ and Rh/Al₂O₃ catalysts. Using computational fluid dynamics, the reactor performance was evaluated in terms of methane conversion and hydrogen yield at temperatures between 700–1000 K, with a gas hourly space velocity of 1000 h⁻¹ and a sweep gas Reynolds number of 100. Simulation results showed that the hybrid CMR achieved a high hydrogen permeation rate with nearly complete methane conversion (≈99.9%) at 1000 K in the steam reforming zone. On the dry reforming side, effective syngas generation and almost complete CO₂ reduction were observed, demonstrating the reactor’s strong potential for efficient hydrogen generation and carbon usage.