US4178348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing sulfur oxides in exhaust gases
Assignee: Chiyoda Corp
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Filing: 1977-06-09
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Granted: 1979-12-11
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Expires: 1997-06-09
Abstract
Abstract This invention relates to a process for desulfurization of exhaust gases containing sulfur oxides. More particularly, it relates to a process which can continuously put in operation to remove the sulfur oxides in exhaust gases in an efficient manner using a slurry of gypsum containing specified sulfate(s) within a single apparatus and can at the same time obtain gypsum as by-product.
Inventors
- 👤 Etsuo Asanagi
- 👤 Hideo Idemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:10
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
86 words
A process for the desulfurization of exhaust gas containing sulfur oxides comprising contacting the exhaust gas with a slurry of gypsum acidified with sulfuric acid to a pH of 4-2.5 and which contains 0.05-0.5 mole/l of at least one metal sulfate selected from the group consisting of zinc, copper and magnesium sulfates in the presence of oxygen, in a single reaction means, while adding lime to the slurry so as to effect the absorption and oxidation of said sulfur oxides and the simultaneous deposition of gypsum.
Claim 2
Dependent Claim
86 words
A process for the desulfurization of exhaust gas containing sulfur oxides comprising contacting the exhaust gas with a slurry of gypsum acidified with sulfuric acid to a pH of 4-2.5 and which contains 0.05-0.5 mole/l of at least one metal sulfate selected from the group consisting of zinc, copper and magnesium sulfates in the presence of oxygen, in a single reaction means, while adding lime to the slurry so as to effect the absorption and oxidation of said sulfur oxides and the simultaneous deposition of gypsum.
Claim 3
Dependent Claim
21 words
The process as defined in claim 1, wherein the concentration of gypsum solids in said slurry of gypsum is 0.1-1.5 mole/l.
Claim 4
Dependent Claim
113 words
A process for the desulfurization of exhaust gas containing sulfur oxides comprising contacting the exhaust gas with a slurry of gypsum acidified with sulfuric acid to a pH of 4-2.5 and which contains 0.05-0.5 mole/l of at least one metal sulfate selected from the group consisting of zinc, copper and magnesium sulfates and a catalytic amount of at least one metal ion selected from the group consisting of Fe 2+ , Ni 2+ , Co 2+ and Mn 2+ in the presence of oxygen, in a single reaction means, while adding lime to the slurry so as to effect the absorption and oxidation of said sulfur oxides and the simultaneous deposition of gypsum.
Claim 5
Dependent Claim
113 words
A process for the desulfurization of exhaust gas containing sulfur oxides comprising contacting the exhaust gas with a slurry of gypsum acidified with sulfuric acid to a pH of 4-2.5 and which contains 0.05-0.5 mole/l of at least one metal sulfate selected from the group consisting of zinc, copper and magnesium sulfates and a catalytic amount of at least one metal ion selected from the group consisting of Fe 2+ , Ni 2+ , Co 2+ and Mn 2+ in the presence of oxygen, in a single reaction means, while adding lime to the slurry so as to effect the absorption and oxidation of said sulfur oxides and the simultaneous deposition of gypsum.
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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) | 1982-12-10 | 1983-06-11 | 1983-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-10 | 1987-06-11 | 1987-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-10 | 1991-06-11 | 1991-12-11 | $7700.00 | Window Closed / Lapsed |