Hydrogen production using sorption-enhanced reaction

This study examined the sorption-enhanced production of H-2 via the steam-m ethane reforming process using a mixture of Ni-based commercial reforming c atalyst and Ca-based sorbent obtained from commercial dolomite. The rates o f the reforming, water-gas shift, and CO2 removal reactions are sufficientl y fast that combined reaction equilibrium was closely approached, allowing for > 95 mol% H-2 (dry basis) to be produced in a single step. A dolomite p retreatment procedure was developed to remove sulfur, which was necessary t o avoid poisoning of the reforming catalyst. The multicycle durability of t he catalyst-sorbent mixture was studied as a function of regeneration tempe rature and gas composition using a laboratory-scale fixed-bed reactor. Twen ty-five-cycle tests showed only moderate activity loss under most of the re generation conditions studied. The primary loss in activity was associated with the inexpensive sorbent instead of the more expensive catalyst.