Abstract: The invention provides a catalyst; a method for making the catalyst and a method for using the catalyst to promote the selective oxidation of hydrogen sulfide into elemental sulfur. The catalyst may be prepared by contacting a catalyst support, such as silica, with a solution containing ammonium metal salts, such as ammonium iron citrate and ammonium zinc citrate, and an amount of chloride (e.g., ammonium chloride) that is between about 0.1 and about 20 weight percent of the metal ions in the solution, to produce a support material impregnated with ammonium metal citrate salts and ammonium chloride. This impregnated catalyst support is then dried and calcined to produce a catalyst, such as iron and zinc oxide mixture supported on silica. It has been found that by adding chloride to the impregnated catalyst support prior to calcination and drying, that the sintering of the metal oxides can be controlled and the formation of a mixed metal oxide is promoted.

Abstract: A method is provided for removing hydrogen sulfide and hydrogen polysulfide compounds out of liquid sulfur by stripping with a gas, such as air. The method is conducted in an apparatus equipped with at least two degassing compartments and a sulfur collection pit wherein the degassing compartments are separated from each other by a first partition wall, the last degassing compartment is separated from the sulfur collection pit by a second partion wall and each degassing compartment contains at least first and second subcompartments which are separated from each other by a third partion wall and are open to each other at the top and the bottom. At least one first subcompartment in each said degassing compartment is provided, at the bottom thereof, with a plurality of stripping gas inlet nozzles and at least one second subcompartment in each said degassing compartment is not provided with stripping gas inlet nozzles.