US4461754A
Expired / Lapsed
US
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Method of removing hydrogen sulfide from gases utilizing a stabilized chelate solution
Assignee: Shell USA Inc
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Filing: 1982-09-30
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Granted: 1984-07-24
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Expires: 2002-09-30
Abstract
Abstract A cyclic process for the removal of hydrogen sulfide, and carbon dioxide, from a variety of gas streams is disclosed. The gas stream containing the sour gas(es) is contacted with an aqueous solution of a specific reactant ligand or chelate, or mixtures thereof, optionally in an absorbent, containing specific stabilizers for improvement of chelate life. The hydrogen sulfide is converted to sulfur, CO 2 may be absorbed to produce a purified gas stream, and the reactant chelate is reduced. The process includes sulfur removal and regeneration of the reactant chelate.
Inventors
- 👤 Zaida Diaz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:51
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/16; C01B17/167; B; B01; B01D; B01D53/00; B01D53/14; B01D53/1493; Y; Y02; Y02P; Y02P20/00; Y02P20/151
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
141 words
A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture containing crystalline sulfur and a reduced reactant; (b) removing at least a portion of the crystalline sulfur from the aqueous admixture; (c) regenerating the aqueous admixture in a regeneration zone to produce a regenerated reactant; (d) returning aqueous admixture containing regenerated reactant from the regeneration zone to the contacting zone.
Claim 2
Dependent Claim
141 words
A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture containing crystalline sulfur and a reduced reactant; (b) removing at least a portion of the crystalline sulfur from the aqueous admixture; (c) regenerating the aqueous admixture in a regeneration zone to produce a regenerated reactant; (d) returning aqueous admixture containing regenerated reactant from the regeneration zone to the contacting zone.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the stream from which the H 2 S is removed is selected from naturally-occurring gases, synthesis gases, process gases and fuel gas.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream.
Claim 5
Dependent Claim
150 words
A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture containing crystalline sulfur and a reduced reactant; (b) regenerating the aqueous admixture in a regeneration zone to produce an aqueous admixture containing a regenerated reactant; (c) removing at least a portion of the crystalline sulfur from aqueous admixture from step (b) to produce an aqueous admixture having reduced sulfur content; (d) returning aqueous admixture content to the contacting zone.
Claim 6
Dependent Claim
150 words
A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture containing crystalline sulfur and a reduced reactant; (b) regenerating the aqueous admixture in a regeneration zone to produce an aqueous admixture containing a regenerated reactant; (c) removing at least a portion of the crystalline sulfur from aqueous admixture from step (b) to produce an aqueous admixture having reduced sulfur content; (d) returning aqueous admixture content to the contacting zone.
Claim 7
Dependent Claim
28 words
The method of claim 4 wherein the stream from which the H 2 S is removed is selected from naturally-occurring gases, synthesis gases, process gases and fuel gas.
Claim 8
Dependent Claim
27 words
The method of claim 4 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream.
Claim 9
Dependent Claim
177 words
A process for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gaseous stream and an absorbent admixture containing absorbed CO 2 , crystalline sulfur, and reduced reactant; (b) removing at least a portion of the crystalline sulfur from the absorbent mixture, and leabing a solution containing absorbed CO 2 and reduced reactant; (c) stripping the solution containing absorbed CO 2 and said reduced reactant to remove CO 2 , and regenerating said solution, producing a lean CO 2 -selective absorbent solution regenerated reactant; and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone.
Claim 10
Dependent Claim
177 words
A process for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gaseous stream and an absorbent admixture containing absorbed CO 2 , crystalline sulfur, and reduced reactant; (b) removing at least a portion of the crystalline sulfur from the absorbent mixture, and leabing a solution containing absorbed CO 2 and reduced reactant; (c) stripping the solution containing absorbed CO 2 and said reduced reactant to remove CO 2 , and regenerating said solution, producing a lean CO 2 -selective absorbent solution regenerated reactant; and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone.
Claim 11
Dependent Claim
192 words
A press for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gaseous stream and an absorbent mixture containing absorbed CO 2 , crystalline sulfur, and reduced reactant; (b) stripping the absorbent mixture containing absorbed CO 2 , crystalline sulfur, and said reduuced reactant, and regenerating said absorbent mixture, producing a lean CO 2 -selective absorbent solution containing a regenerated reactant and sulfur, (c) removing at least a portion of the crystalline sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the regenerated reactant, and leaving a lean CO 2 -selective absorbent solution containing regenerated reactant, and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone.
Claim 12
Dependent Claim
192 words
A press for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing polyvalent metal chelate compounds, and mixtures thereof, and stabilizing amount of a composition selected from the group consisting of 2,2-thiodiethanol, zinc isopropylxanthate, and mixtures thereof, and producing a sweet gaseous stream and an absorbent mixture containing absorbed CO 2 , crystalline sulfur, and reduced reactant; (b) stripping the absorbent mixture containing absorbed CO 2 , crystalline sulfur, and said reduuced reactant, and regenerating said absorbent mixture, producing a lean CO 2 -selective absorbent solution containing a regenerated reactant and sulfur, (c) removing at least a portion of the crystalline sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the regenerated reactant, and leaving a lean CO 2 -selective absorbent solution containing regenerated reactant, and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone.
Claim 13
Dependent Claim
20 words
The process of claim 2 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 14
Dependent Claim
19 words
The process of claim 2 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
Claim 15
Dependent Claim
20 words
The process of claim 3 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 16
Dependent Claim
19 words
The process of claim 3 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
Claim 17
Dependent Claim
20 words
The process of claim 5 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 18
Dependent Claim
19 words
The process of claim 5 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
Claim 19
Dependent Claim
20 words
The process of claim 6 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 20
Dependent Claim
19 words
The process of claim 6 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
Claim 21
Dependent Claim
20 words
The process of claim 7 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 22
Dependent Claim
19 words
The process of claim 7 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
Claim 23
Dependent Claim
20 words
The process of claim 8 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.
Claim 24
Dependent Claim
19 words
The process of claim 8 wherein the oxidizing polyvalent metal chelate compound is the Fe(III) chelate of nitrilotriacetic acid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |