US4387037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of sulfur from waste gas streams
Assignee: GULF INTERSTATE ENGINEERING COMPANY A DE CORP
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Filing: 1981-12-11
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Granted: 1983-06-07
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Expires: 2001-12-11
Abstract
Abstract Preferential sulfur dioxide absorption solvents may be buffered with suitable agents, such as alkanolaminium carboxylates, to substantially retard or eliminate the tendency of such solvents to degrade or accumulate non-regenerable salts, particularly sulfates, when loaded with absorbed sulfur dioxide. A method for employing the buffer as an immiscible aqueous phase as a separate trimming solvent to selectively absorb residual sulfur dioxide from a gas stream from which the bulk amount of sulfur dioxide is first removed by contact with a trialkyl phosphate solvent is disclosed. The method permits the trialkyl phosphate solvent to be regenerated and purged of salts at lower energy requirements.
Inventors
- 👤 H. Lee Trentham
- 👤 John H. Crow
- 👤 Farwell C. Boston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:26
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/60; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/507
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
56 words
A buffered degradation resistant sulfur dioxide absorption solvent, comprising: a water soluble trialkyl phosphate containing at least about five (5) percent by weight water in admixture with a buffering agent selected from the group consisting of alkanolaminium carboxylates, alkali metal salts of carboxylic acids or benzoic acid, and ammonium salts of carboxylic acids or benzoic acid.
Claim 2
Dependent Claim
56 words
A buffered degradation resistant sulfur dioxide absorption solvent, comprising: a water soluble trialkyl phosphate containing at least about five (5) percent by weight water in admixture with a buffering agent selected from the group consisting of alkanolaminium carboxylates, alkali metal salts of carboxylic acids or benzoic acid, and ammonium salts of carboxylic acids or benzoic acid.
Claim 3
Dependent Claim
24 words
The solvent of claim 1, wherein the trialkyl phosphate is a lower alkyl having alkyl groups of from one to about four carbon atoms.
Claim 4
Dependent Claim
11 words
The solvent of claim 1, wherein the trialkyl phosphate is triethyphosphate.
Claim 5
Dependent Claim
24 words
The solvent of claim 1, wherein the buffering agent is a sodium or potassium salt of a C 1 to C 5 carboxylic acid.
Claim 6
Dependent Claim
18 words
The solvent of claim 2, wherein the trialkyl phosphate and the buffering agent is sodium or potassium acetate.
Claim 7
Dependent Claim
14 words
The solvent of claim 2, wherein the buffering agent is sodium or potassium benzoate.
Claim 8
Dependent Claim
15 words
The solvent of claim 2, wherein the buffering agent is ammonium acetate or ammonium benzoate.
Claim 9
Dependent Claim
22 words
The solvent of claim 2, wherein the trialkyl phosphate is triethyl phosphate and the buffering agent is methyldiethanolaminium acetate or triethanolaminium acetate.
Claim 10
Dependent Claim
59 words
The solvent of claim 1, wherein the buffering agent is an alkanolaminium carboxylate of the following formula: ##STR2## wherein R 4 is a lower alkyl having from one to four carbon atoms and R 1 , R 2 and R 3 each independently represents hydrogen or a lower alkyl or a hydroxalkyl having from one to four carbon atoms.
Claim 11
Dependent Claim
77 words
A process for reducing degradation of a trialkyl phosphate preferential sulfur dioxide absorption solvent while such solvent is loaded with absorbed sulfur dioxide, comprising the steps of co-mingling with said solvent a buffering agent selected from the group consisting of alkanolaminium carboxylates, alkali metal salts of carboxylic acids or benzoic acid, and ammonium salts of carboxylic acids or benzoic acid; and maintaining said buffering agent in contact with said solvent until absorbed sulfur dioxide is removed therefrom.
Claim 12
Dependent Claim
77 words
A process for reducing degradation of a trialkyl phosphate preferential sulfur dioxide absorption solvent while such solvent is loaded with absorbed sulfur dioxide, comprising the steps of co-mingling with said solvent a buffering agent selected from the group consisting of alkanolaminium carboxylates, alkali metal salts of carboxylic acids or benzoic acid, and ammonium salts of carboxylic acids or benzoic acid; and maintaining said buffering agent in contact with said solvent until absorbed sulfur dioxide is removed therefrom.
Claim 13
Dependent Claim
59 words
The process of claim 10, wherein the buffering agent is an alkanolaminium carboxylate of the following formula: ##STR3## wherein R 4 is a lower alkyl having from one to four carbon atoms and R 1 , R 2 and R 3 each independently represents hydrogen or a lower alkyl or a hydroxalkyl having from one to four carbon atoms.
Claim 14
Dependent Claim
24 words
The process of claim 10, wherein the buffering agent is a sodium or potassium salt of a C 1 to C 5 carboxylic acid.
Claim 15
Dependent Claim
18 words
The process of claim 12, wherein the trialkyl phosphate and the buffering agent is sodium or potassium acetate.
Claim 16
Dependent Claim
14 words
The process of claim 12, wherein the buffering agent is sodium or potassium benzoate.
Claim 17
Dependent Claim
15 words
The process of claim 12, wherein the buffering agent is ammonium acetate or ammonium benzoate.
Claim 18
Dependent Claim
46 words
The process of claim 10, wherein the preferential sulfur dioxide absorption solvent is a water soluble trialkyl phosphate is a lower alkyl having alkyl groups of from one to about four carbon atoms and the solvent contains at least about five (5%) percent by weight water.
Claim 19
Dependent Claim
12 words
The process of claim 16, wherein the trialkyl phosphate is triethyl phosphate.
Claim 20
Dependent Claim
15 words
The process of claim 17, wherein the buffering agent is methyldiethanolaminium acetate or triethanolaminium acetate.
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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) | 1986-06-06 | 1986-12-06 | 1987-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-06 | 1990-12-06 | 1991-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-06 | 1994-12-06 | 1995-06-07 | $7700.00 | Window Closed / Lapsed |