Patent ID: 8518356

Claim:
A method for treating a feed gas, comprising CO 2 , H 2 S and H 2 , to produce an H 2 -enriched product and an H 2 S-lean, CO 2 product, the method comprising: separating the feed gas by pressure swing adsorption to form a stream of H 2 -enriched product gas and a stream of sour gas, the sour gas also 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; dividing the stream of sour gas into two parts; processing one part of said stream of sour gas in an H 2 S removal system to form one or more streams of sweetened gas, depleted in H 2 S and enriched in CO 2 relative to the feed gas; bypassing the H 2 S removal system with the other part of said stream of sour gas; and combining said stream(s) of sweetened gas with said sour gas bypassing the H 2 S removal system to form a stream of H 2 S-lean, CO 2 product gas; wherein the division of the sour gas between being sent to and processed in the H 2 S removal system and bypassing said system is adjusted responsive to changes in the H 2 S content of the sour gas, such that the proportion of the sour gas processed in the H 2 S removal system, as compared to bypassing said system, is increased if the H 2 S content rises and decreased if the H 2 S content drops.