| A method of separating hydrogen from syngas for use as a carbon-free energy carrier is reported. The process consists of a hydrogen enrichment step and a solids regeneration step in a lab-scale, fixed-bed reactor. During the enrichment step, syngas and steam are passed through iron oxide and calcium oxide beds where multiple reactions occur simultaneously to yield a stream of pure hydrogen. The syngas and steam feeds are then replaced by air to regenerate the solids, releasing sequestration ready carbon dioxide. The effects of moderate temperatures (600-800 °C), steam and syngas concentrations, residence time, and solids composition on hydrogen purity were studied. The information obtained was used to optimize the process and achieve a 99 % hydrogen stream. Ten cycles were completed with a minimal loss in performance observed. BET and particle size analysis were performed before and after cycling to study physical changes undergone by the solids. |
