US4501668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the elimination of hydrogen sulfide or iron sulfide from an aqueous system
Assignee: Evonik Operations GmbH
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Filing: 1983-12-06
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Granted: 1985-02-26
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Expires: 2003-12-06
Abstract
Abstract There are employed water soluble low molecular weight polycondensation products produced by the condensation of acrolein and formaldehyde in a molar ratio between 1:1 and 1:10 in aqueous or aqueous-organic medium in the presence of a basic catalyst for the elimination of hydrogen sulfide and iron sulfide present in aqueous systems. The condensation reaction can also be carried out in the additional presence of water soluble monohydric or polyhydric alcohols and/or acid amides.
Inventors
- 👤 Wolfgang Merk
- 👤 Karl-Heinz Rink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:25
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/173; C02; C02F; C02F1/00; C02F1/50; C02F5/00; C02F5/08; C02F5/10; C09; C09K; C09K8/00; C09K8/54; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/916; Y10S507/00; Y10S507/939
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
84 words
A process for the elimination of hydrogen sulfide, iron sulfide or a mixture of iron sulfide and hydrogen sulfide from an aqueous system comprising adding to the system an effective amount of a water soluble low molecular weight condensation product of acrolein and formaldehyde in the molar ratio of 1:1 to 1:10, said condensation product having been produced in the presence of a basic catalyst, to react with said hydrogen sulfide, said iron sulfide, or said mixture, and form an odor free aqueous solution.
Claim 2
Dependent Claim
84 words
A process for the elimination of hydrogen sulfide, iron sulfide or a mixture of iron sulfide and hydrogen sulfide from an aqueous system comprising adding to the system an effective amount of a water soluble low molecular weight condensation product of acrolein and formaldehyde in the molar ratio of 1:1 to 1:10, said condensation product having been produced in the presence of a basic catalyst, to react with said hydrogen sulfide, said iron sulfide, or said mixture, and form an odor free aqueous solution.
Claim 3
Dependent Claim
21 words
A process according to claim 1 wherein the acrolein-formaldehyde condensation product is made from reactants consisting essentially of acrolein and formaldehyde.
Claim 4
Dependent Claim
30 words
A process according to claim 1 wherein the acrolein-formaldehyde condensation product is made from reactants consisting essentially of (1) acrolein, (2) formaldehyde and (3) an alcohol or an acid amide.
Claim 5
Dependent Claim
15 words
A process according to claim 3 wherein reactant (3) is a monohydric or polyhydric alcohol.
Claim 6
Dependent Claim
12 words
A process according to claim 4 wherein reactant 3 is allyl alcohol.
Claim 7
Dependent Claim
14 words
A process according to claim 3 wherein reactant 3 is a carboxylic acid amide.
Claim 8
Dependent Claim
11 words
A process according to claim 6 wherein the amide is formamide.
Claim 9
Dependent Claim
19 words
A process according to claim 1 wherein the molar ratio of acrolein to formaldehyde is from 1:2 to 1:4.
Claim 10
Dependent Claim
16 words
A process according to claim 8 wherein the molar ratio of acrolein to formaldehyde is 1:4.
Claim 11
Dependent Claim
22 words
A process according to claim 9 wherein there is added between 5 and 500 ppm of the condensate to the aqueous system.
Claim 12
Dependent Claim
22 words
A process according to claim 8 wherein there is added between 5 and 500 ppm of the condensate to the aqueous system.
Claim 13
Dependent Claim
22 words
A process according to claim 1 wherein there is added between 1 and 2000 ppm of the condensate to the aqueous system.
Claim 14
Dependent Claim
22 words
A process according to claim 12 wherein there is added between 5 and 2000 ppm of the condensate to the aqueous system.
Claim 15
Dependent Claim
22 words
A process according to claim 13 wherein there is added between 5 and 500 ppm of the condensate to the aqueous system.
Claim 16
Dependent Claim
22 words
A process according to claim 13 wherein there is added between 1000 and 2000 ppm of the condensate to the aqueous system.
Claim 17
Dependent Claim
41 words
A process according to claim 15 including the further step of reducing the concentration of the condensate in the aqueous system to 5 to 500 ppm after an initial reduction in the amount of hydrogen sulfide present in the aqueous system.
Claim 18
Dependent Claim
15 words
A process according to claim 1 wherein the aqueous system is free from iron sulfide.
Claim 19
Dependent Claim
13 words
A process according to claim 1 wherein the aqueous system contains iron sulfide.
References Cited (Backward Citations)
US2267276A
Cited
FR1356707A
Cited
NL6906485A
Cited
DE1938634A1
Cited
US3687615A
Cited
US3883303A
Cited
US4160656A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |