Catalytic incineration of hydrogen sulfide from gas streams

Claim 2

A process for oxidizing H 2 S to SO 2 in a feed gas containing a minor proportion of H 2 S and a substantial proportion of at least one secondary oxidizable component selected from the class consisting of H 2 , CO, and light hydrocarbons, which process comprises: (1) contacting said feed gas, in admixture with sufficient oxygen to convert at least about 80% of said H 2 S to SO 2 , with an oxidation catalyst at a temperature between about 300° and 900° F. and at a space velocity correlated with temperature so as to convert at least about 80% of said H 2 S to SO 2 without oxidizing substantially any of said secondary oxidizable components, said oxidation catalyst comprising a vanadium oxide and/or sulfide as the essential active component supported on a crystalline, non-alkaline porous refractory oxide comprising hydrogen mordenite having a silica-to-alumina ratio between about 10:1 and 100:1 and (2) recovering a gaseous effluent of reduced H 2 S content, but still containing essentially all of said secondary oxidizable component or components.

Claim 3

A process as defined in claim 1 wherein said oxygen in step (1) is provided in excess of the stoichiometric amount required to oxidize said minor proportion of H 2 S to SO 2 and said secondary oxidizable component is H 2 .

Claim 4

A process as defined in claim 2 wherein said oxygen in step (1) is supplied in the form of air and said feed gas-oxygen admixture is contacted with said catalyst at a temperature between about 600° and 900° F.

Claim 5

A process as defined in claim 2 wherein said refractory oxide comprises hydrogen mordenite having a silica-to-alumina ratio between about 10:1 and 40:1.

Claim 6

A process as defined in claim 2 wherein said oxidation catalyst comprises between about 1 and 30 weight percent V 2 O 5 .

Claim 7

A process as defined in claim 5 wherein said feed gas comprises ammonia.

Claim 8

A process as defined in claim 2 wherein said contacting in step (1) is controlled to convert at least about 90% of said H 2 S to SO 2 .

Claim 9

A process as defined in claim 2 wherein said feed gas is the off-gas from a preceding partial oxidation of a relatively H 2 S-rich gas wherein a substantial portion of H 2 S was oxidized to elemental sulfur followed by separation of said elemental sulfur therefrom.

Claim 10

A process as defined in claim 8 wherein said partial oxidation was effected by contacting said H 2 S-rich gas, in admixture with sufficient oxygen to convert at least about 50% of said H 2 S to elemental sulfur, with an oxidation catalyst at a temperature between about 250° and 450° F. and at a space velocity correlated with temperature so as to convert at least about 50% of said H 2 S to elemental sulfur, said oxidation catalyst comprising a vanadium oxide and/or sulfide supported on a non-alkaline porous refractory oxide.

Claim 11

A process as defined in claim 9 wherein said non-alkaline, porous refractory oxide of step (1) consists essentially of hydrogen mordenite having a silica-to-alumina ratio between about 10:1 and 40:1.

Claim 12

A process for treating a feed gas stream containing, as essentially the only oxidizable components therein, H 2 S and one or more secondary oxidizable components selected from the class consisting of H 2 , CO, and light hydrocarbons, said feed gas stream further containing at least sufficient oxygen to convert a substantial proportion of said H 2 S to SO 2 , which process comprises: (1) maintaining the H 2 S concentration of said feed gas stream at a substantially constant value and maintaining the temperature of said feed gas stream at a substantially constant value between about 300° and 750° F.; (2) contacting said feed gas stream with an oxidation catalyst so as to convert a substantial proportion of said H 2 S to SO 2 without oxidizing substantially any of said secondary oxidizable components, said oxidation catalyst comprising a vanadium oxide and/or sulfide as the essential active component supported on a crystalline non-alkaline porous refractory oxide comprising hydrogen mordenite having a silica-to-alumina ratio between about 10:1 and 100:1; and (3) recovering a gaseous effluent of reduced H 2 S content, but still containing essentially all of the secondary oxidizable component or components originally present in said feed gas stream, said gaseous effluent being at a substantially constant temperature between about 500° and 900° F., and said constant temperature being such that the temperature rise in step (2) is substantially constant and substantially directly proportional to the concentration of the H 2 S in said feed gas stream.

Claim 13

A process for treating a feed gas stream containing, as essentially the only oxidizable components therein, H 2 S and one or more secondary oxidizable components selected from the class consisting of H 2 , CO, and light hydrocarbons, said feed gas stream further containing at least sufficient oxygen to convert a substantial proportion of said H 2 S to SO 2 , which process comprises: (1) maintaining the H 2 S concentration of said feed gas stream at a substantially constant value and maintaining the temperature of said feed gas stream at a substantially constant value between about 300° and 750° F.; (2) contacting said feed gas stream with an oxidation catalyst so as to convert a substantial proportion of said H 2 S to SO 2 without oxidizing substantially any of said secondary oxidizable components, said oxidation catalyst comprising a vanadium oxide and/or sulfide as the essential active component supported on a crystalline non-alkaline porous refractory oxide comprising hydrogen mordenite having a silica-to-alumina ratio between about 10:1 and 100:1; and (3) recovering a gaseous effluent of reduced H 2 S content, but still containing essentially all of the secondary oxidizable component or components originally present in said feed gas stream, said gaseous effluent being at a substantially constant temperature between about 500° and 900° F., and said constant temperature being such that the temperature rise in step (2) is substantially constant and substantially directly proportional to the concentration of the H 2 S in said feed gas stream.

Claim 14

A process as defined in claim 11 wherein said secondary oxidizable component is H 2 .

Claim 15

A process as defined in claim 12 wherein said oxygen is supplied in excess of the stoichiometric amount required to oxidize said H 2 S to SO 2 .

Claim 16

A process as defined in claim 13 wherein said feed gas stream contains CO and H 2 .

Claim 17

A process as defined in claim 11 wherein said feed gas stream contains CO and H 2 .