US4683076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the removal of H2 S from geothermal steam and the conversion to sulfur using ferric chelate and cationic polymer
Assignee: Dow Chemical Co
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Filing: 1986-04-04
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Granted: 1987-07-28
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Expires: 2006-04-04
Abstract
Abstract Process for removing H 2 S from the exhaust steam in a geothermal power plant wherein the H 2 S containing steam is contacted with an aqueous solution containing a ferric chelate and a cationic polymeric catalyst such as poly dimethyl diallyl ammonium chloride. The conversion of H 2 S to sulfur is accelerated by the use of a small amount of the catalyst.
Inventors
- 👤 Robert D. Lampton, Jr.
- 👤 II Thomas M. Hopkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:56
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05; F; F03; F03G; F03G4/00; F03G4/074
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
34 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts.
Claim 2
Dependent Claim
34 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts.
Claim 3
Dependent Claim
30 words
The composition of claim 1 wherein the range for said iron is 3.5 to 10 weight percent and the range for said polymeric catalyst is 0.75 to 5.0 weight percent.
Claim 4
Dependent Claim
41 words
A composition comprising of an aqueous solution containing the ferric chelate of N-hydroxyethyl ethylene diamine triacetic acid in an amount to give 4 to 5 percent by weight of iron and 1.0 to 3.0 percent by weight of poly(dimethyldiallyl ammonium chloride).
Claim 5
Dependent Claim
41 words
A composition comprising of an aqueous solution containing the ferric chelate of N-hydroxyethyl ethylene diamine triacetic acid in an amount to give 4 to 5 percent by weight of iron and 1.0 to 3.0 percent by weight of poly(dimethyldiallyl ammonium chloride).
Claim 6
Dependent Claim
66 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts whereby said chelate is derived from a chelating agent selected from the group consisting of nitrilotriacetic acid, N-hydroxyethyliminodiacetic acid, ethylenediamine tetraacetic acid, N-hydroxyethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, cyclohexanediaminetetraacetic acid, and triethylenetetraamine hexaacetic acid.
Claim 7
Dependent Claim
66 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts whereby said chelate is derived from a chelating agent selected from the group consisting of nitrilotriacetic acid, N-hydroxyethyliminodiacetic acid, ethylenediamine tetraacetic acid, N-hydroxyethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, cyclohexanediaminetetraacetic acid, and triethylenetetraamine hexaacetic acid.
Claim 8
Dependent Claim
30 words
The composition of claim 4 wherein the range for said iron is 3.5 to 10 weight percent and the range for said polymeric catalyst is 0.75 to 5.0 weight percent.
Claim 9
Dependent Claim
58 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts whereby said cationic polymeric catalyst is selected from the group consisting of polyethyleneamines, poly(2-hydroxypropyl-1-N-methylammonium chloride), poly(2-hydroxypropyl-1-N-dimethylammonium chloride), poly[N-(dimethylamminomethyl)-acrylamide], poly(2-vinylimidazolinum bisulfate), poly(diallyldimethylammonium chloride) and poly(N-dimethylaminopropyl)-methacrylamide.
Claim 10
Dependent Claim
58 words
A composition comprising an aqueous solution containing sufficient soluble ferric chelate to give 3 to 15 percent iron and 0.5 to 10.0 percent by weight of one or more water soluble cationic polymeric catalysts whereby said cationic polymeric catalyst is selected from the group consisting of polyethyleneamines, poly(2-hydroxypropyl-1-N-methylammonium chloride), poly(2-hydroxypropyl-1-N-dimethylammonium chloride), poly[N-(dimethylamminomethyl)-acrylamide], poly(2-vinylimidazolinum bisulfate), poly(diallyldimethylammonium chloride) and poly(N-dimethylaminopropyl)-methacrylamide.
Claim 11
Dependent Claim
30 words
The composition of claim 6 wherein the range for said iron is 3.5 to 10 weight percent and the range for said polymeric catalyst is 0.75 to 5.0 weight percent.
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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) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |