Systems and processes for removing hydrogen sulfide from gas streams
AssigneeMarsulex Environmental Technologies Corporation
InventorsMichael Lyn Mengel, Amy Patrice Evans, Eli Gal, Paul Murray Leicht
Life of this patent
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Abstract
A process and system for hydrogen sulfide capture from gas streams employing an absorber vessel in which the gas stream containing hydrogen sulfide is contacted with an absorbent solution to remove the hydrogen sulfide from the gas stream. The process and system may further employ an oxidation vessel in which sulfides and/or bisulfides in the absorbent solution are oxidized to produce a thiosulfate and/or sulfate, yielding a solution that can be used as fertilizer or other applications.
Claims19
A process of capturing hydrogen sulfide from a gas stream and oxidizing captured hydrogen sulfide to form a thiosulfate, a sulfate, or a combination thereof, the process comprising:
- obtaining a gas stream containing hydrogen sulfide, the gas stream being natural gas, refinery process gas, or syngas from gasification;
- contacting the gas stream with a first absorbent solution to form sulfides in the first absorbent solution, wherein the first absorbent solution is an ammoniated aqueous absorbent solution containing ammonia and ammonium thiosulfate and/or ammonium sulfate and the ammonia reacts with the hydrogen sulfide to form the sulfides;
- controlling pH of the first absorbent solution during the contacting step;
- oxidizing the first absorbent solution to convert at least some of the sulfides thereof to form an additional amount of ammonium thiosulfate and/or ammonium sulfate, thereby producing a second absorbent solution that contains the additional amount of ammonium thiosulfate and/or ammonium sulfate and has a lower sulfide content than the first absorbent solution;
- and
- delivering a first portion of the second absorbent solution for use in the contacting step to capture residual hydrogen sulfide in the gas stream and capture ammonia emitted from the first absorbent solution;
- and
- discharging a second portion of the second absorbent solution from the system.
A process of capturing hydrogen sulfide from a gas stream and oxidizing captured hydrogen sulfide to form a thiosulfate, a sulfate, or a combination thereof, the process comprising:
- obtaining a gas stream containing hydrogen sulfide, the gas stream being natural gas, refinery process gas, or syngas from gasification;
- contacting the gas stream with an ammoniated aqueous absorbent solution containing ammonia and ammonium thiosulfate and/or ammonium sulfate, the ammonia reacting with the hydrogen sulfide to form sulfides in the ammoniated aqueous absorbent solution;
- controlling pH of the ammoniated aqueous absorbent solution during the contacting step by adding ammonia to the ammoniated aqueous absorbent solution;
- oxidizing the ammoniated aqueous absorbent solution to convert at least some of the sulfides thereof to form an additional amount of ammonium thiosulfate and/or ammonium sulfate, thereby producing a second absorbent solution that contains the additional amount of ammonium thiosulfate and/or ammonium sulfate and has a lower sulfide content than the ammoniated aqueous absorbent solution;
- and
- delivering a first portion of the second absorbent solution for use in the contacting step to capture residual hydrogen sulfide in the gas stream and capture ammonia emitted from the first absorbent solution;
- and
- discharging a second portion of the second absorbent solution from the system.
Dependencies are inferred from the claim text.