Method for removing hydrogen sulfide from gas streams
AssigneeUnion Oil Company of California
InventorsDonald M. Fenton, Hugh W. Gowdy
Life of this patent
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Abstract
A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a substantially quinone-free aqueous washing solution containing, inter alia, solubilized vanadium, thiocyanate ions, and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the washing solution, is separated from the regenerated solution.
Claims21
A method for removing hydrogen sulfide from a hydrogen sulfide-containing gas stream and converting said hydrogen sulfide to elemental sulfur, which comprises:
- (a) contacting said gas stream with a regenerable washing solution so as to absorb said hydrogen sulfide into said washing solution, the washing solution introduced into contact with said gas stream comprising a substantially quinone-free aqueous solution having a pH between about 5 and about 10 and containing (1) solubilized vanadium, (2) one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium, (3) thiocyanate ions and (4) a water-soluble carboxylate complexing agent;
- (b) allowing the absorbed hydrogen sulfide to react with constituents of said washing solution so as to convert said absorbed hydrogen sulfide substantially exclusively to elemental sulfur;
- (c) oxidatively regenerating the washing solution from step (b) so as to form a regenerated washing solution;
- and
- (d) separating said elemental sulfur from said washing solution.
A method for removing hydrogen sulfide from a hydrogen sulfide-containing gas stream and converting said hydrogen sulfide to elemental sulfur, which comprises:
- (a) contacting said gas stream with a regenerable washing solution so as to absorb said hydrogen sulfide into said washing solution, the washing solution introduced into contact with said gas stream comprising a substantially quinone-free aqueous alkaline solution having a pH between about 7 and about 9.5 and containing (1) between about 0.006 and about 0.4 gram-moles of solubilized vanadium per liter, (2) between about 0.01 and about 0.25 gram-moles of one or more water-soluble alkali metal salts of nonquinone hydroxyaromatic sulfonates per liter, (3) between about 30 and about 150 grams of thiocyanate ions per liter, and (4) a water-soluble carboxylate complexing agent;
- (b) allowing the absorbed hydrogen sulfide to react with constituents of said washing solution so as to convert said hydrogen sulfide substantially exclusively to elemental sulfur;
- (c) oxidatively regenerating the washing solution from step (b) so as to form a regenerated washing solution;
- (d) separating said elemental sulfur from said regenerated washing solution;
- and
- (e) recycling the regenerated washing solution from step (d) into contact with said gas stream in step (a).
A method for removing hydrogen sulfide from a hydrogen sulfide-containing gas stream and converting said hydrogen sulfide to elemental sulfur, which comprises:
- (a) contacting said gas stream with a regenerable washing solution so as to absorb said hydrogen sulfide into said washing solution, the washing solution introduced into contact with said gas stream comprising a quinone-free aqueous alkaline solution having a pH between about 8 and about 9 and containing (1) between about 0.01 and about 0.2 gram-moles of solubilized vanadium per liter, (2) between about 0.02 and about 0.15 gram-moles of an alkali metal 1-hydroxybenzene-4-sulfonate per liter, (3) between about 30 and about 150 grams of thiocyanate ions per liter, (4) an alkali metal citrate, and (5) a mixture of alkali metal carbonates and alkali metal bicarbonates;
- (b) allowing the absorbed hydrogen sulfide to react with constituents of said washing solution so as to convert said hydrogen sulfide substantially exclusively to elemental sulfur;
- (c) oxidatively regenerating the washing solution from step (b) so as to form a regenerated washing solution;
- (d) separating said elemental sulfur from said regenerated washing solution;
- and
- (e) recycling the regenerated washing solution from step (d) into contact with said gas stream in step (a).
Dependencies are inferred from the claim text.