Abstract: A process for treating acid gas comprising hydrogen sulfide comprises introducing a first acid gas into a reducing furnace to produce a first oxidized gas stream, cooling the first oxidized gas stream in a first heat recovery system, introducing the cooled gas stream into an oxidizing furnace to produce a second oxidized gas stream and cooling the second oxidized gas stream in a second heat recovery system. The acid gas is preferably produced in a refinery after treatment of sour gas or sour water. Spent acid may be fed into oxidizing furnace as part of a sulfuric acid recovery process. The spent acid can be spent sulfuric acid from a sulfuric acid alkylation process.

Abstract: A process for treating acid gas comprising hydrogen sulfide comprises introducing a first acid gas into a reducing furnace to produce a first oxidized gas stream, cooling the first oxidized gas stream in a first heat recovery system, introducing the cooled gas stream into an oxidizing furnace to produce a second oxidized gas stream and cooling the second oxidized gas stream in a second heat recovery system. The acid gas is preferably produced in a refinery after treatment of sour gas or sour water. Spent acid may be fed into oxidizing furnace as part of a sulfuric acid recovery process. The spent acid can be spent sulfuric acid from a sulfuric acid alkylation process.

Abstract: A process for treating acid gases comprising hydrogen sulfide comprises introducing a first acid gas and a first oxygen-containing gas into a reducing furnace to produce a first oxidized gas stream, cooling the first oxidized gas stream in a first heat recovery system, introducing the cooled gas stream into a sulfur condenser to produce a sulfur-stripped gas, introducing the sulfur-stripped gas and a second oxygen-containing gas into an oxidizing furnace to produce a second oxidized gas stream and cooling the second oxidized gas stream in a second heat recovery system. The first acid gas can be acid gas comprising hydrogen sulfide produced in refineries. The spent acid can be spent sulfuric acid from a sulfuric acid alkylation process. The cooled second oxidized gas stream can be further treated in a spent acid recovery plant or a sulfur recovery unit.

Abstract: The present invention provides a process for removing ammonia as an aqueous salt solution from an acid gas comprising ammonia and hydrogen sulfide. A strong acid, such as sulfuric acid, is used as a scrubbing agent to convert ammonia to an ammonium salt. Control of pH and stripping in combination with reboiler or evaporators reduces hydrogen sulfide concentration. The ammonium salt is produced as an aqueous solution, which may crystallized to form a solid product. The ammonium salt solution or solid may be used as a fertilizer.