Low-Pressure Sorption-Enhanced Hydrogen Production

The sorption-enhanced production of hydrogen involves the simultaneous steam−methane reforming, water−gas shift, and CO 2 removal reactions in the presence of a reforming catalyst and CO 2 sorbent. High concentrations of H 2 with low concentrations of CO are produced in a single reaction step. Pure CO 2 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 CO 2 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 °C using a H 2 O-to-CH 4 feed ratio of 3. Calcined Arctic SHB dolomite proved to be an effective CO 2 sorbent that did not require pretreatment for sulfur removal.