US3793171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing pollutants from gas streams
Assignee: Carrier Corp
•
Filing: 1970-09-04
•
Granted: 1974-02-19
•
Expires: 1990-09-04
Abstract
Abstract A process for removing oxidizable impurities from ''''waste'''' gas streams which comprises contacting the gas stream, typically air, which carries the oxidizable impurities with an aqueous acid stream containing an electrolytically regenerable oxidizing agent. After a sufficient contact time to remove oxidizable impurities from the gas stream, the gas stream is removed from the contact area with a lowered impurity content and vented or further treated as desired, the aqueous acid stream containing the electrolytically regenerable oxidizing agent and oxidizable impurities is removed from the contact area, the electrolytically regenerable oxidizing agent is regenerated, and the above described cycle is repeated. Preferably, the regenerable metal oxidizing agent is cobalt in the +3 valence state and the aqueous stream contains sulfuric acid. Destruction of oxidizable impurities is continuous throughout the system, i.e., in the mass transfer contact area, the electrolytic regeneration area and in all process interconnections. Apparatus in accordance with the present invention comprises a contact area for mass transfer between the acid stream containing the electrolytically regenerable oxidizing agent and the gas stream containing the oxidizable impurities and electrolytic means for regenerating the electrolytically regenerable oxidizing agent.
Inventors
- 👤 P Chang
- 👤 E Zabolotny
- 👤 W Biermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:13
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/96; B01D53/965; A; A61; A61L; A61L9/00; A61L9/015; A61L9/02; A61L9/03; B01D53/74; B01D53/77; B01D53/78; B01D2251/00; B01D2251/50; B01D2251/506
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
25 words
The process of claim 1 further comprising separating said aqueous acid stream from said gas stream after said contacting and prior to said electrolytic regeneration.
Claim 2
Dependent Claim
23 words
The process of claim 2 further comprising recycling said aqueous acid stream after said electrolytic regeneration for further contacting with said gas stream.
Claim 3
Dependent Claim
53 words
The process of claim 2 wherein said electrolytically regenerable oxidizing agent is cobalt in ionic form and said aqueous acid stream is rendered acidic by the inclusion therein of a mineral acid selected from the group consisting of sulfuric acid, phosphoric acid, perchloric acid, water soluble acid salts derived therefrom and mixtures thereof.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein the electrolytically regenerable oxidizing agent is chromium in ionic form.
Claim 5
Dependent Claim
16 words
The process of claim 1 wherein the electrolytically regenerable oxidizing agent is manganese in ionic form.
Claim 6
Dependent Claim
16 words
The process of claim 1 wherein the electrolytically regenerable oxidizing agent is cerium in ionic form.
Claim 7
Dependent Claim
38 words
The process of claim 1 wherein said oxidizable impurities are destroyed by said electrolytically regenerable oxidizing agent at a rate at least equal to the rate at which said oxidizable impurites are transferred into said aqueous acid stream.
Claim 8
Dependent Claim
51 words
The process of claim 1 wherein said aqueous acid stream contains oxidizable impurities after said contacting and at least a portion of said oxidizable impurities are destroyed during said electrolytic regeneration as a result of an electric current passed through said aqueous acid stream to regenerate said electrolytically regenerable oxidizing agent.
Claim 9
Dependent Claim
23 words
The process of claim 1 wherein the temperature of said gas stream is substantially equal to the temperature of said aqueous acid stream.
Claim 10
Dependent Claim
21 words
The process of claim 10 wherein the temperature of said aqueous acid stream is from about 32* to about 130* F.
Claim 11
Dependent Claim
24 words
The process of claim 1 wherein said aqueous acid stream is at a pH less than 1 and a normality less than about 27.5.
Claim 12
Dependent Claim
40 words
The process of claim 12 wherein said aqueous acid stream is rendered acid by the inclusion therein of a member selected from the group consisting of mineral acids, water soluble acid salts derived from said mineral acids and mixtures thereof.
Claim 13
Dependent Claim
25 words
The process of claim 13 wherein said mineral acid is selected from the group consisting of sulfuric acid, phosphoric acid, perchloric acid and mixtures thereof.
Claim 14
Dependent Claim
13 words
The process of claim 1 wherein the aqueous acid stream comprises perchloric acid.
Claim 15
Dependent Claim
18 words
The process of claim 1 wherein the aqueous acid stream comprises sulphuric acid, phosphoric acid and perchloric acid.
Claim 16
Dependent Claim
56 words
The process of claim 2, wherein said aqueous acid stream is at a pH less than 1 and has a normality less than 27.5, and said aqueous acid stream is rendered acid by the inclusion therein of a member selected from the group consisting of mineral acids, water soluble acid salts derived therefrom, and mixtures thereof.
Claim 17
Dependent Claim
47 words
The process of claim 17 wherein said electrolytically regenerable oxidizing agent is cobalt in ionic form and said acid stream is rendered acidic by the inclusion therein, of a member selected from the group consisting of sulfuric acid, water soluble acid salts derived therefrom and mixtures thereof.
Claim 18
Dependent Claim
16 words
The process of claim 1 wherein said electrolytically regenerable oxidizing agent is cobalt in ionic form.
Claim 19
Dependent Claim
16 words
The process of claim 1 wherein both organic and inorganic odorous and pollutant impurities are destroyed.
Claim 20
Dependent Claim
14 words
The process of claim 20 where only organic odorous and pollutant impurities are destroyed.
Claim 21
Dependent Claim
14 words
The process of claim 20 where only inorganic odorous and pollutant impurities are destroyed.
Claim 22
Dependent Claim
110 words
The process of claim 1 wherein: the aqueous acid stream is separated from the gas stream after the contacting but prior to subjecting the aqueous acid stream to electrolytic regeneration, whereby a portion of the odorous and pollutant impurities are destroyed, the remainder of the odorous and pollutant impurities carried in the aqueous acid stream being recycled in said aqueous acid stream to contact incoming gas stream containing incoming odorous and pollutant impurities, the remainder of the odorous and pollutant impurities being in a state of dynamic equilibrium with the incoming odorous and pollutant impurities prior to, during and after passage of the electrical current rhough the aqueous acid stream.
Claim 23
Dependent Claim
65 words
The process of claim 23 wherein said odorous and pollutant impurities comprise water soluble impurities which are dissolved to yield a negatively and positively charged species, the negatively charged species being subjected to electrical migration during the electrolytic regeneration and being in part anoDically destroyed and the positively charged species also being subjected to migration during the electrolytic regeneration and being in part cathodically destroyed.
Claim 24
Dependent Claim
33 words
The process of claim 24 wherein the odorous and pollutant impurities further comprise water insoluble impurities which are destroyed by transient species generated during the passage of electrical current through the aqueous stream.
Claim 25
Dependent Claim
152 words
A continuous process for destroying oxidizable odorous and pollutant impurities carried in a gas stream comprising: contacting said gas stream in mass transfer relationship with an aqueous acid stream containing cobalt (III) to transfer oxidizable impurities from said gas stream to said aqueous acid stream and to destroy oxidizable impurities by said cobalt (III) thereby converting the cobalt (III) to cobalt (II) thus reducing its capacity to oxidize further oxidizable impurities, said acid stream being rendered acidic by the inclusion therein of a member selected from the group consisting of sulfuric acid, water soluble acid salts derived therefrom, and mixtures thereof; electrolytically regenerating cobalt (II) to cobalt (III) while carried in said aqueous acid stream to restore the capacity of said aqueous acid stream to oxidize further pollutant impurities; and utilizing said regenerated aqueous acid stream containing regenerated Co(III) to contact additional oxidizable odorous and pollutant impurities carried in a gas stream.
Claim 26
Dependent Claim
25 words
The process of claim 26 further comprising separating said aqueous acid stream from said gas stream after said contacting and prior to said electrolytic regeneration.
Claim 27
Dependent Claim
23 words
The process of claim 27 further comprising recycling said aqueous acid stream after said electrolytic regeneration for further contacting with said gas stream.
Claim 28
Dependent Claim
24 words
The process of claim 28 wherein said aqueous acid stream is at a pH less than 1 and a normality less than about 27.5.
Claim 29
Dependent Claim
20 words
The process of claim 29 wherein said aqueous acid stream is rendered acid by the inclusion therein of sulfuric acid.
Claim 30
Dependent Claim
19 words
The process of claim 30 wherein the amount of cobalt in said aqueous acid stream is above 0.002 M.
Claim 31
Dependent Claim
25 words
The process of claim 31 wherein from about 5 to 20 percent of said cobalt, on a molar basis, is Co(III), the balance being Co(II).
Claim 32
Dependent Claim
27 words
The process of claim 32 wherein the amount of cobalt in said aqueous acid stream is above 0.005 M and less than the saturation point of cobalt.
Claim 33
Dependent Claim
20 words
The process of claim 33 wherein contacting, regenerating and recycling are conducted at substantially the temperature of the gas stream.
Claim 34
Dependent Claim
35 words
The process of claim 26 wherein said oxidizable impurities are destroyed by the Co(III) at a rate at least equal to the rate at which said oxidizable impurities are transferred into said aqueous acid stream.
Claim 35
Dependent Claim
52 words
The process of claim 26 wherein said aqueous acid stream contains oxidizable impurities after said contacting and at least a portion of said oxidizable impurites are destroyed during said electrolytic regeneration as a result of the electric current passed through said aqueous acid stream to regenerate the cobalt (II) to cobalt (III).
Claim 36
Dependent Claim
21 words
The process of claim 26 wherein the temperature of said aqueous acid stream is from about 32* to about 130* F.
Claim 37
Dependent Claim
46 words
The process of claim 26 wherein the cobalt is used in combination with a different multi-valence electrolytically regenerable ionic oxidizing agent selected from the group consisting of a metal other than cobalt in ionic form and a mixture of metals other than cobalt in ionic form.
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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |