US3656887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing hydrogen sulfide from gaseous mixtures
Assignee: Chevron USA Inc
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Filing: 1969-08-21
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Granted: 1972-04-18
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Expires: 1989-08-21
Abstract
Abstract The process for selectively removing H2S and like sulfides from fluids containing them by contact with a cyanopyridine (e.g., a mixture of ortho and meta cyanopyridines) and an alkali hydrosulfide, preferably in a substantially hydroxyl-free solvent such as N-methyl pyrrolidone. Preferably, in the process an admixture of H2S and CO2 in natural gas is contacted with the cyanopyridine containing contacting solution to react the H2S with said cyanopyridine, the CO2 and/or like hydrocarbons are rejected from the contacting solution by mild heating and/or pressure reduction and thereafter H2S is regenerated by heating the remaining solution.
Inventors
- 👤 Shigeto Suzuki
- 👤 Giok H Tjoa
- 👤 Karl H Kilgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:14
CPC Classifications
C; C10; C10K; C10K1/00; C10K1/08; C10K1/16; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/52; B01D53/523; C07; C07C; C07C7/00; C07C7/11
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
A process for removing hydrogen sulfide from a gas mixture containing said hydrogen sulfide, which process comprises contacting said gas mixture with a cyanopyridine and an alkali hydrosulfide selected from the group consisting of potassium hydrosulfide, sodium hydrosulfide, lithium hydrosulfide, ammonium hydrosulfide, and dimethyl ammonium hydrosulfide, or compounds capable of producing one of said hydrosulfides in a substantially hydroxyl-free solvent, said cyanopyridine, hydrosulfide and solvent constituting contacting solution and separating the hydrogen sulfide-enriched contacting solution from a resulting gas mixture of reduced sulfide content.
Claim 2
Dependent Claim
19 words
The process of claim 2 wherein said contacting solution is regenerated by heating and removing the dissociated hydrogen sulfide.
Claim 3
Dependent Claim
11 words
The process of claim 2 wherein said solvent is a pyrrolidone.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein said solvent is N-methyl-2-pyrrolidone and said contacting is carried out at a temperature below about 250* F.
Claim 5
Dependent Claim
16 words
The process of claim 2 wherein said cyanopyridine is a mixture of ortho and meta cyanopyridines.
Claim 6
Dependent Claim
21 words
The process of claim 2 wherein solvent initially contains a compound capable of producing an alkali hydrosulfide under the reaction conditions.
Claim 7
Dependent Claim
12 words
The process of claim 2 wherein said alkali hydrosulfide is potassium hydrosulfide.
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) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |