US4772366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical separation and concentration of sulfur containing gases from gas mixtures
Assignee: Gas Technology Institute
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Filing: 1987-03-06
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Granted: 1988-09-20
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Expires: 2007-03-06
Abstract
Abstract An electrochemical cell is provided for removing H 2 S from a gas mixture. The cell includes porous, gas diffusion electrodes and a membrane containing an aqueous alkaline polysulfide electrolyte. H 2 S is reduced to polysulfide ions at one electrode and the ions migrate through the membrane to the other electrode where they are oxidized to form elemental sulfur. Another embodiment of the invention utilizes a solvent to remove the H 2 S from the gas mixture. Bisulfide ions are formed and are oxidized in an electrochemical cell to form elemental sulfur. The solvent is regenerated in the cell and recycled.
Inventors
- 👤 Jack Winnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 00:16
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; B; B01; B01D; B01D53/00; B01D53/32; B01D53/326; C01B17/0495; C01B17/20; C25; C25B; C25B1/00; C25B1/01
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
85 words
A method for removing H 2 S from a gas mixture, said method comprising the steps of: providing an electrochemical cell with a porous cathode and a porous anode; providing the electrochemical cell with an aqueous electrolyte; effecting current flow between the cathode and anode; directing the gas mixture containing the H 2 S into contact with the cathode to cause reduction of the H 2 S to polysulfide ions; and allowing the polysulfide ions to migrate from the cathode and concentrate at the anode.
Claim 2
Independent Claim
85 words
A method for removing H 2 S from a gas mixture, said method comprising the steps of: providing an electrochemical cell with a porous cathode and a porous anode; providing the electrochemical cell with an aqueous electrolyte; effecting current flow between the cathode and anode; directing the gas mixture containing the H 2 S into contact with the cathode to cause reduction of the H 2 S to polysulfide ions; and allowing the polysulfide ions to migrate from the cathode and concentrate at the anode.
Claim 3
Dependent Claim
34 words
The invention of claim 1, including the step of maintaining the current flow between the cathode and anode while the polysulfide ions concentrate at the anode to oxidize the polysulfide ions to elemental sulfur.
Claim 4
Dependent Claim
17 words
The invention of claim 2, including the step of removing the elemental sulfur from the electrochemical cell.
Claim 5
Dependent Claim
32 words
The invention of claim 1, including the step of directing a stream of H 2 gas into contact with the anode to effect the flow of current between the cathode and anode.
Claim 6
Dependent Claim
28 words
The invention of claim 1, wherein the step of effecting current flow between the cathode and anode comprises providing an external power source across the cathode and anode.
Claim 7
Dependent Claim
20 words
The invention of claim 1, wherein the step of providing an aqueous electrolyte comprises providing an aqueous alkali-metal polysulfide solution.
Claim 8
Dependent Claim
36 words
The invention of claim 6, wherein the step of providing an aqueous alkali-metal polysulfide solution comprises providing one or more polysulfides selected from the group consisting of sodium, potassium, cesium, tetramethyl ammonium and tetraethyl ammonium polysulfides.
Claim 9
Dependent Claim
23 words
The invention of claim 1, wherein the step of providing a porous cathode and anode comprises providing a nickel based cathode and anode.
Claim 10
Dependent Claim
36 words
The invention of claim 8, wherein the step of providing a nickel based cathode and anode includes the step of providing at least one catalyst selected from the group consisting of cobalt sulfide and molybdenum disulfide.
Claim 11
Dependent Claim
24 words
The invention of claim 1, including the step of passing hydrogen gas across the anode to oxidize the polysulfide ions to H 2 S.
Claim 12
Independent Claim
94 words
A method operable at ambient temperature for the removal of H 2 S from a gas mixture, said method utilizing an electrochemical cell comprising a cathode, an anode and an aqueous polysulfide electrolyte and comprising the steps of: effecting a flow of current between the cathode and anode; directing the gas mixture containing the H 2 S into contact with the cathode to reduce the H 2 S to polysulfide ions; allowing the polysulfide ions to migrate through the electrolyte from the cathode to the anode; and oxidizing the polysulfide ions at the anode.
Claim 13
Independent Claim
94 words
A method operable at ambient temperature for the removal of H 2 S from a gas mixture, said method utilizing an electrochemical cell comprising a cathode, an anode and an aqueous polysulfide electrolyte and comprising the steps of: effecting a flow of current between the cathode and anode; directing the gas mixture containing the H 2 S into contact with the cathode to reduce the H 2 S to polysulfide ions; allowing the polysulfide ions to migrate through the electrolyte from the cathode to the anode; and oxidizing the polysulfide ions at the anode.
Claim 14
Dependent Claim
28 words
The invention of claim 11, wherein the step of effecting a flow of current between the cathode and anode comprises directing hydrogen gas into contact with the anode.
Claim 15
Dependent Claim
23 words
The invention of claim 11, wherein the step of oxidizing the polysulfide ions at the anode results in the formation of elemental sulfur.
Claim 16
Independent Claim
88 words
A method for the removal of H 2 S from a gas mixture, said method comprising the steps of; directing the gas mixture to a column; contacting the gas mixture in the column with a solvent to reduce the H 2 S to bisulfide ions; directing the solvent and bisulfide ions into contact with an anode contained in an electrochemical cell comprising the anode, a cathode and a membrane; and effecting a flow of current between the anode and cathode to form elemental sulfur from the bisulfide ions.
Claim 17
Independent Claim
88 words
A method for the removal of H 2 S from a gas mixture, said method comprising the steps of; directing the gas mixture to a column; contacting the gas mixture in the column with a solvent to reduce the H 2 S to bisulfide ions; directing the solvent and bisulfide ions into contact with an anode contained in an electrochemical cell comprising the anode, a cathode and a membrane; and effecting a flow of current between the anode and cathode to form elemental sulfur from the bisulfide ions.
Claim 18
Dependent Claim
15 words
The invention of claim 14, including the step of removing the sulfur from the solvent.
Claim 19
Dependent Claim
28 words
The invention of claim 14, wherein the step of contacting the gas mixture with a solvent includes the step of providing a solvent comprising hydroxide and bisulfide ions.
Claim 20
Dependent Claim
26 words
The invention of claim 16, including the step of regenerating the solvent by directing the solvent from the anode to the cathode to form hydroxide ions.
Claim 21
Dependent Claim
21 words
The invention of claim 17, including the step of returning the regenerated solvent to the column and repeating the previous steps.
Claim 22
Dependent Claim
27 words
The invention of claim 17, wherein the step of directing the solvent to the cathode to form hydroxide ions comprises passing O 2 gas across the cathode.
Claim 23
Dependent Claim
41 words
The invention of claim 14, wherein the step of contacting the gas mixture with a solvent comprises the step of providing a solvent selected from the group consisting of aqueous sodium, potassium, lithium, cesium and tetramethyl ammonium sulfides and mixtures thereof.
Claim 24
Dependent Claim
26 words
The invention of claim 11, wherein the aqueous polysulfide electrolyte is selected from the group consisting of sodium, potassium, cesium, tetramethyl ammonium, and tetraethyl ammonium polysulfides.
Claim 25
Independent Claim
93 words
A method for the removal of H 2 S from a gas mixture said method comprising the steps of: directing the gas mixture to a column; contacting the gas mixture in the column with a solvent comprising hydroxide and bisulfide ions to reduce the H 2 S to bisulfide ions; directing the solvent and bisulfide ions into contact with an anode contained in an electrochemical cell comprising the anode, a cathode and a membrane; and effecting a flow of current between the anode and cathode to form elemental sulfur from the bisulfide ions.
Claim 26
Independent Claim
93 words
A method for the removal of H 2 S from a gas mixture said method comprising the steps of: directing the gas mixture to a column; contacting the gas mixture in the column with a solvent comprising hydroxide and bisulfide ions to reduce the H 2 S to bisulfide ions; directing the solvent and bisulfide ions into contact with an anode contained in an electrochemical cell comprising the anode, a cathode and a membrane; and effecting a flow of current between the anode and cathode to form elemental sulfur from the bisulfide ions.
Claim 27
Dependent Claim
15 words
The invention of claim 22, including the step of removing the sulfur from the solvent.
Claim 28
Dependent Claim
26 words
The invention of claim 22, including the step of regenerating the solvent by directing the solvent from the anode to the cathode to form hydroxide ions.
Claim 29
Dependent Claim
21 words
The invention of claim 24, including the step of returning the regenerated solvent to the column and repeating the previous steps.
Claim 30
Dependent Claim
27 words
The invention of claim 24, wherein the step of directing the solvent to the cathode to form hydroxide ions comprises passing O 2 gas across the cathode.
Claim 31
Dependent Claim
41 words
The invention of claim 22, wherein the step of contacting the gas mixture with a solvent comprises the step of providing a solvent selected from the group consisting of aqueous sodium, potassium, lithium, cesium and tetramethyl ammonium sulfides and mixtures thereof.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |