Low-pressure sorption-enhanced hydrogen production

The sorption-enhanced production of hydrogen involves the simultaneous steam-methane reforming, water-gas shift, and CO2 removal reactions in the presence of a reforming catalyst and CO2 sorbent. High concentrations of H-2 with low concentrations of CO are produced in a single reaction step. Pure CO2 suitable for use or sequestration may be produced during sorbent regeneration. This study examined the sorption-enhanced H-2 production reactions at low pressure, which also requires a low reaction temperature so that the sorbent will retain its effectiveness for CO2 capture. H-2 concentrations in excess of 96 mol % (dry basis) and CO concentrations as low as 7 ppmv (dry basis) were produced in tests between 1 and 5 bar and 400 and 460 degrees C using a H2O-to-CH4 feed ratio of 3. Calcined Arctic SHB dolomite proved to be an effective CO2 sorbent that did not require pretreatment for sulfur removal.