Patent attributes
A cyclic process for selectively separating hydrogen sulfide from a gas mixture including CO2 is operated by contacting the gas mixture under sorption conditions with a non-aqueous sorbent comprising a basic non-protogenic nitrogenous compound to react the H2S with the basic compound so that the H2S can be sorbed by the compound. The compound containing the sorbed H2S can then be subjected to desorption conditions by which the H2S is desorbed and the sorbent readied for another sorption step in the cycle. The basic nitrogenous compound can be carried on a porous solid sorbent, e.g., a solid oxide such as alumina, silica, silica-alumina, zeolites, or a mesoporous and/or macroporous solid oxide. The process may be operated using a pressure swing, temperature swing, partial pressure swing, purge displacement, or a combination thereof between the sorption and desorption portions of the cycle, preferably in a rapid cycle operation.
