Method for desulfurizing a gas

Abstract

A foul gas containing H.sub.2 S is brought into the presence of SO.sub.2 in a first stage to permit the reaction between SO.sub.2 and H.sub.2 S to form water and elemental sulfur. The SO.sub.2 is solubilized in an absorbent composition which includes a solvent for both SO.sub.2 and H.sub.2 S so that the H.sub.2 S in the foul gas is first solubilized in the absorbent composition where it is then brought into contact with the solubilized SO.sub.2 for reaction between a major portion of the H.sub.2 S and the solubilized SO.sub.2 to form elemental sulfur. The gas is then passed to a second stage where any remaining H.sub.2 S is removed by aqueous catalytic reaction of the type conventional in the prior art. The apparatus utilized to carry out the present invention preferably includes a two stage column in which the first stage provides the absorbent material containing solubilized SO.sub.2 for reaction with the H.sub.2 S of the foul gas. During the SO.sub.2 extraction stage the major portion of the H.sub.2 S is removed from the foul gas. The gas is then conveyed from the first stage to a second stage which comprises a conventional aqueous catalytic scrubbing operation where the remainder of the H.sub.2 S is removed. The absorbent composition utilized in the process comprises solvents that dissolve SO.sub.2 and/or H.sub.2 S which can be heated to a temperature above the melting point of sulfur without detrimentally affecting the solvent so that it may be recycled through the system.

Dependencies are inferred from the claim text.