US4921683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitric oxide abatement with polymeric cobalt(III) chelates
Assignee: Dow Chemical Co
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Filing: 1989-06-20
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Granted: 1990-05-01
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Expires: 2009-06-20
Abstract
Abstract An NO abatement process wherein an NO-containing fluid is contacted with a polymeric cobalt(II) dioxygen diamine complex. The aqueous solution is recovered, purified by membrane separation to remove low molecular weight reaction products, optionally electrolytically regenerated, and recycled for the NO-containing gas contact. The cobalt(II) is complexed with an amine-containing polymer such as polyethyleneimine free of acidic, e.g. carboxylate, chelating groups.
Inventors
- 👤 Stephen A. Bedell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:45
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/14; B01D61/145; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
128 words
A method for abating nitric oxide in a fluid stream, comprising the steps of: (A) contacting a fluid stream containing nitric oxide with an aqueous solution of a polymeric cobalt(II) diamine dioxygen complex, wherein said complex is obtained by (a) complexing (i) a cobalt(II) salt with (ii) a water soluble, basic polymer comprising polyethyleneimine containing secondary amine groups, wherein the molar ratio of said amine groups to cobalt(II) is from 3 to 6, and (b) oxygenating the resulting polymeric cobalt(II) diamine complex; (B) recovering aqueous solution resulting from said contact with said fluid stream in step (A); (C) purifying said recovered aqueous solution to remove low molecular weight reaction products; and (D) recycling the purified solution from step (C) for reuse in the aqueous solution of step (A).
Claim 2
Independent Claim
128 words
A method for abating nitric oxide in a fluid stream, comprising the steps of: (A) contacting a fluid stream containing nitric oxide with an aqueous solution of a polymeric cobalt(II) diamine dioxygen complex, wherein said complex is obtained by (a) complexing (i) a cobalt(II) salt with (ii) a water soluble, basic polymer comprising polyethyleneimine containing secondary amine groups, wherein the molar ratio of said amine groups to cobalt(II) is from 3 to 6, and (b) oxygenating the resulting polymeric cobalt(II) diamine complex; (B) recovering aqueous solution resulting from said contact with said fluid stream in step (A); (C) purifying said recovered aqueous solution to remove low molecular weight reaction products; and (D) recycling the purified solution from step (C) for reuse in the aqueous solution of step (A).
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein said fluid stream contains oxygen.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein said fluid stream is essentially free of sulfur oxides.
Claim 5
Dependent Claim
19 words
The method of claim 1, wherein said water soluble polymer has a molecular weight between about 500 and 1,000,000.
Claim 6
Dependent Claim
30 words
The method of claim 1, wherein said polymer is essentially free of acidic chelating groups in excess of a 1:1 molar ratio of said acidic groups to said amine groups.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein said purification is by ultrafiltration or dialysis.
Claim 8
Dependent Claim
24 words
The method of claim 1, wherein said purification removes at least a portion of said reaction products with a molecular weight less than 1000.
Claim 9
Dependent Claim
16 words
The method of claim 1, further comprising the step of electrolytically regenerating said recovered aqueous solution.
Claim 10
Independent Claim
176 words
A method for abating nitric oxide in a fluid stream, comprising the steps of: (A) contacting a fluid stream containing oxygen and nitric oxide in a contacting zone with an aqueous solution of a polymeric cobalt(II) diamine complex effective to produce a fluid stream of reduced nitrogen oxide content, wherein said complex is obtained by complexing (i) a cobalt(II) salt with (ii) polyethyleneimine having a molecular weight between about 500 and 1,000,000 and containing secondary amine groups, wherein the molar ratio of said amine groups to cobalt(II) is from 3 to 6, and wherein said polyethyleneimine is free of acidic chelating groups in an amount equal to or in excess of a 1:1 molar ratio of said acidic groups to said amine groups; (B) recovering the resulting aqueous phase produced in step (A); (C) concentrating the aqueous phase recovered in step (B) by membrane separation by effectively removing a portion of reaction products having a molecular weight below 1000; and (D) recycling the concentrated aqueous phase from step (C) to the contacting zone in step (A).
Claim 11
Independent Claim
176 words
A method for abating nitric oxide in a fluid stream, comprising the steps of: (A) contacting a fluid stream containing oxygen and nitric oxide in a contacting zone with an aqueous solution of a polymeric cobalt(II) diamine complex effective to produce a fluid stream of reduced nitrogen oxide content, wherein said complex is obtained by complexing (i) a cobalt(II) salt with (ii) polyethyleneimine having a molecular weight between about 500 and 1,000,000 and containing secondary amine groups, wherein the molar ratio of said amine groups to cobalt(II) is from 3 to 6, and wherein said polyethyleneimine is free of acidic chelating groups in an amount equal to or in excess of a 1:1 molar ratio of said acidic groups to said amine groups; (B) recovering the resulting aqueous phase produced in step (A); (C) concentrating the aqueous phase recovered in step (B) by membrane separation by effectively removing a portion of reaction products having a molecular weight below 1000; and (D) recycling the concentrated aqueous phase from step (C) to the contacting zone in step (A).
Claim 12
Dependent Claim
15 words
The method of claim 9, wherein said fluid stream is essentially free of sulfur oxides.
Claim 13
Dependent Claim
14 words
The method of claim 9, wherein said fluid stream comprises gas turbine flue gas.
Claim 14
Dependent Claim
18 words
The method of claim 9, wherein said polyethyleneimine has a molecular weight of between about 1,000 and 500,000.
Claim 15
Dependent Claim
22 words
The method of claim 9, wherein said membrane separation comprises ultrafiltration effective to remove reaction products with a molecular weight below 500.
Claim 16
Dependent Claim
21 words
The method of claim 9, wherein said molar ratio of secondary amine groups to cobalt(II) is between about 4 and 5.
Claim 17
Dependent Claim
23 words
The method of claim 9, further comprising the step of electrolytically regenerating cobalt(III) in the aqueous phase recovered in step (B) to cobalt(II).
Claim 18
Dependent Claim
21 words
The method of claim 9, wherein said contacting zone is maintained at a temperature between about 25° C. and 60° C.
Claim 19
Dependent Claim
10 words
The method of claim 9, wherein said polyethyleneimine is unsubstituted.
Claim 20
Dependent Claim
14 words
The method of claim 9, wherein said polyethyleneimine is essentially free of acidic substituents.
Claim 21
Dependent Claim
18 words
The method of claim 9, wherein the fluid stream is flue gas cooled to below about 60° C.
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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) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |