Patent ID: 8206669

Claim:
A method for treating a feed gas, comprising about 10 to about 65 mole % CO 2 , about 50 ppm to about 5 mole % H 2 S and at least about 30 mole % H 2 , to produce an H 2 -enriched product and a CO 2 product, the method comprising: separating the feed gas by pressure swing adsorption (PSA) to obtain a stream of H 2 -enriched product gas and two streams of sour gas, each sour gas stream comprising CO 2 , H 2 S and H 2 but being depleted in H 2 and enriched in H 2 S and CO 2 relative to the feed gas, each sour gas stream containing at least about 5 mole % H 2 and at most about 10 mole % H 3 S; processing one of said streams of sour gas in an H 2 S to elemental sulfur conversion system by contacting the sour gas with SO 2 , sulfuric acid and/or sulfurous acid to convert H 2 S to elemental sulfur and form a stream of sweetened gas, said sweetened gas being enriched in CO 2 and depleted in H 2 S and H 2 relative to the feed gas; processing the other of said streams of sour gas in an oxidation system by oxidizing at least about 90% of H 2 S and at least about 90% of the H 2 in the sour gas via reaction with O 2 to produce heat and form an oxidation effluent, said effluent comprising CO 2 , SO x (SO 2 and SO 3 ) and H 2 O and being enriched in CO 2 and depleted in H 2 S and H 2 relative to the feed gas, and: (i) introducing into the H 2 S to elemental sulfur conversion system at least a portion of the SO 2 obtained from the oxidation system, so as to provide at least a portion of said SO 2 for reaction with H 2 S in the H 2 S to elemental sulfur conversion system; and/or (ii) converting at least a portion of the SO x obtained from the oxidation system to sulfuric and/or sulfurous acid, and introducing at least a portion of said acid into the H 2 S to elemental sulfur conversion system to provide at least a portion of said acid for reaction with H 2 S in the H 2 S to elemental sulfur conversion system; and forming the CO 2 product from said stream of sweetened gas obtained from the H 2 S to elemental sulfur conversion system.