Process for removal of hydrogen sulfide from gas streams

Claim 1

A process for the desulfurization of a feed gas containing at least one sulfur component selected from the class consisting of SO 2 , COS, CS 2 , CH 3 SH, SO 3 , and sulfur vapor, which process, being carried out for at least 30 days, comprises the steps of: (1) contacting said feed gas at a temperature between about 300° and 800° F. with a hydrofining catalyst comprising a combination of a Group VIB metal oxide and/or sulfide with an iron group metal oxide and/or sulfide, said feed gas being contacted with said catalyst at a space velocity correlated with temperature, and in the presence of sufficient of one or more components selected from the class consisting of water vapor, H 2 , and CO, so as to convert at least about 80% of said sulfur components to H 2 S by hydrolysis and/or hydrogenation; (2) dehydrating the resulting hydrofined gas to a water vapor content of less than about 15 volume percent; (3) contacting, at a temperature between about 250° and 450° F., a mixture of said dehydrated hydrofined gas and a gaseous oxidant comprising sufficient elemental oxygen to oxidize at least 80% of said H 2 S to sulfur with a catalyst comprising a vanadium oxide and/or sulfide supported on a non-alkaline porous refractory oxide, said contacting being carried out at a space velocity correlated with temperature so as to oxidize at least 80% of the H 2 S contained in said dehydrated hydrofined gas to elemental sulfur vapor, with said catalyst maintaining substantially undiminished activity for oxidizing H 2 S to sulfur under essentially the same conditions for at least 30 days of contacting; and (4) separating free sulfur from the resulting gaseous effluent, and recovering a purified product gas.