Recovery of sulfur from sulfur dioxide rich aqueous absorbents

Claim 1

In a process for recovering sulfur in which sulfur dioxide containing gas is contacted with an aqueous absorbent to form an aqueous absorbent containing sulfur dioxide with a pH in the range of about 2.5 to about 5.0, and the aqueous absorbent containing sulfur dioxide is contacted with hydrogen sulfide to form sulfur and sulfur is separated from the aqueous absorbent, the improvement which comprises; providing a reaction-separation zone containing aqueous absorbent in the lower portion thereof and void space in the upper portion, forming a mixture of gas bubbles in the aqueous absorbent by passing a gaseous mixture containing hydrogen sulfide into a circulating zone of aqueous absorbent thereby forming a gas-liquid mixture, and passing the mixture through a zone of stationary apertures wherein the size of the gas bubbles in the mixture is reduced and whereby hydrogen sulfide in the gas is contacted with the aqueous absorbent containing sulfur dioxide to form sulfur, said gas mixture containing hydrogen sulfide is provided in an amount sufficient to react with the sulfur dioxide to form sulfur and to float the sulfur formed to the surface of the body of absorbent by the rising gas bubbles whereby the sulfur is separated from the aqueous absorbent.