US4102804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inhibitor for gas conditioning solutions
Assignee: Dow Chemical Co
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Filing: 1977-03-28
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Granted: 1978-07-25
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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, a water-soluble sulfide or a water-soluble thiocyanate.
Inventors
- 👤 Robert C. Clouse
- 👤 Robert G. Asperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:00
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1493; C; C23; C23F; C23F11/00; C23F11/06; C23F11/08; C23F11/10; Y; Y02; Y02C; Y02C20/00; Y02C20/40
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
55 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, a water-soluble sulfide, or an organic thioamide.
Claim 2
Dependent Claim
55 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, a water-soluble sulfide, or an organic thioamide.
Claim 3
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 4
Dependent Claim
12 words
The inhibited solution of claim 2 wherein the thio compound is thiourea.
Claim 5
Dependent Claim
14 words
The inhibited solution of claim 2 wherein the thio compound is NH 4 SCN.
Claim 6
Dependent Claim
21 words
The inhibited solution of claim 2 wherein R in the pyridinium salt formula is an alkyl radical of 10-18 carbon atoms.
Claim 7
Dependent Claim
14 words
The inhibited solution of claim 5 wherein the pyridinium salt is tetradecyl polyalkylpyridinium bromide.
Claim 8
Dependent Claim
33 words
The inhibited solution of claim 1 wherein the sour gas conditioning solution is a solution of a lower alkanolamine, sulfolane, potassium carbonate, or a mixture thereof in water, glycol, or a waterglycol mixture.
Claim 9
Dependent Claim
13 words
The composition of claim 7 wherein the solution is an aqueous lower alkanolamine.
Claim 10
Dependent Claim
10 words
The composition of claim 8 wherein the alkanolamine is ethanolamine.
Claim 11
Dependent Claim
10 words
The composition of claim 8 wherein the alkanolamine is diethanolamine.
Claim 12
Dependent Claim
16 words
The composition of claim 8 wherein the solution is a mixture of aqueous diisopropanolamine and sulfolane.
Claim 13
Dependent Claim
23 words
The inhibited solution of claim 1 wherein the concentration of the inhibitor combination is at least about 50 parts per million by weight.
Claim 14
Dependent Claim
14 words
An inhibitor composition consisting essentially of thiourea and the pyridinium salt of claim 1.
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) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |