Separation of hydrogen from syngas using a regenerative system

A method of separating hydrogen from syngas for use as a carbon-free energy carrier is reported. The overall process consists of a hydrogen enrichment step and a solids regeneration step in a lab-scale, fixed-bed reactor under atmospheric pressure. 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 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 degrees C), steam concentration, syngas concentration, 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 using the same solids were completed with a minimal loss in performance observed. (C) 2007 International Association for Hydrogen Energy.