Method for removing hydrogen sulfide from sulfur-bearing industrial gases with claus-type reactors

Integrating an absorption-desorption step, a Claus plant, and a catalytic hydrogen reactor in a recycle loop provides a gas-desulfuration plant that operates at a substantially zero emission level. Hydrogen sulfide is removed from industrial gas streams by absorption-desorption in a liquid absorbent. The resulting foul gas is then reacted with sulfur dioxide in a Claus reaction, i.e., the reaction of hydrogen sulfide with sulfur dioxide to form elemental sulfur and water. The tail gas from this Claus reaction is then passed through a catalytic hydrogenation reactor together with a supply of hydrogen to reduce the sulfur and sulfur compounds to hydrogen sulfide. The now reduced tail gas is then recycled back to the industrial gas, upstream of the absorption-desorption step.