US4100100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cobalt-containing inhibitor for sour gas conditioning solutions
Assignee: Dow Chemical Co
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Filing: 1977-03-28
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Granted: 1978-07-11
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Expires: 1997-03-28
Abstract
Abstract The corrosion of iron and steel by an aqueous sour gas conditioning solution used to remove CO 2 from a gas stream is effectively inhibited by a combination of a quaternary pyridinium salt and an organic thioamide or water-soluble thiocyanate. The addition of a small amount of a water-soluble cobalt salt to the inhibitor combination improves its effectiveness.
Inventors
- 👤 Robert C. Clouse
- 👤 Robert G. Asperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:44
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/06; C23F11/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
74 words
A sour gas conditioning solution inhibited against CO 2 promoted corrosion of iron and steel by having dissolved therein an inhibiting concentration of a combination of one part by weight of a quaternary pyridinium salt and about 0.001-10 parts of a thio compound which is a water-soluble thiocyanate or an organic thioamide, and, in addition to the above, a small but effective amount of cobalt, said cobalt present as a dissolved divalent cobalt compound.
Claim 2
Dependent Claim
74 words
A sour gas conditioning solution inhibited against CO 2 promoted corrosion of iron and steel by having dissolved therein an inhibiting concentration of a combination of one part by weight of a quaternary pyridinium salt and about 0.001-10 parts of a thio compound which is a water-soluble thiocyanate or an organic thioamide, and, in addition to the above, a small but effective amount of cobalt, said cobalt present as a dissolved divalent cobalt compound.
Claim 3
Dependent Claim
28 words
The inhibited solution of claim 1 wherein the cobalt is present in a concentration of about 5- 500 parts per million based on the weight of the solution.
Claim 4
Dependent Claim
115 words
The inhibited solution of claim 1 wherein the pyridinium salt has the formula: ##STR4## wherein R is an alkyl radical of 1-20 carbon atoms, a benzyl radical, or an alkylated benzyl radical wherein the aromatic ring has one or more alkyl substituents totaling 1-20 carbon atoms, each R' is a hydrogen atom or an alkyl radical of 1-6 carbon atoms, and X is an anionic radical and the organic thioamide is thiourea, a polythiourea, a hydrocarbon substituted derivative thereof, or a thioamide having the formula: ##STR5## wherein A is a hydrocarbon radical of 1-12 carbon atoms or a pyridyl radical and each R" is a hydrogen atom or an alkyl radical of 1-8 carbon atoms.
Claim 5
Dependent Claim
21 words
The inhibited solution of claim 3 wherein R in the pyridinium salt formula is an alkyl radical of 10-18 carbon atoms.
Claim 6
Dependent Claim
20 words
The inhibited solution of claim 4 wherein the pyridinium salt is tetradecyl polyalkylpyridinium bromide and the thio compound is thiourea.
Claim 7
Dependent Claim
32 words
The inhibited solution of claim 1 wherein the sour gas conditioning solution is a solution of a lower alkanolamine, sulfolane, potassium carbonate, or mixture thereof in water, glycol, or a water-glycol mixture.
Claim 8
Dependent Claim
14 words
The inhibited solution of claim 6 wherein the solution is an aqueous lower alkanolamine.
Claim 9
Dependent Claim
11 words
The inhibited solution of claim 7 wherein the alkanolamine is ethanolamine.
Claim 10
Dependent Claim
24 words
The inhibited solution of claim 1 wherein the concentration of the total inhibitor combination is at least about 55 parts per million by weight.
Claim 11
Dependent Claim
14 words
The inhibited solution of claim 1 wherein the cobalt concentration is about 10-50 ppm.
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) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |