US4024220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flue gas scrubbing and conversion of calcium sulfite to calcium sulfate
Assignee: Honeywell UOP LLC
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Filing: 1975-08-25
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Granted: 1977-05-17
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Expires: 1995-08-25
Abstract
Abstract In the scrubbing of sulfur compound containing stack gases, there is an advantage to converting calcium sulfite to calcium sulfate downstream from the scrubber in order to provide for smaller sludge handling equipment and to form a more usable sludge. Thus, in the present operation, there is provided an ozonation of the withdrawn scrubber bottoms slurry to effect the conversion of calcium sulfite in such slurry to calcium sulfate.
Inventors
- 👤 Norman Ostroff
- 👤 Nurhan E. Takvoryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:20
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; C; C01; C01F; C01F11/00; C01F11/46; C01F11/464
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
204 words
A method for effecting the calcium slurry scrubbing and desulfurizing of a sulfur-containing flue gas stream in a manner to minimize the bulk of resulting calcium-sulfur compounds, which comprises the steps of: a. substantially removing extrained particulates from the flue gas stream by an electrostatic preciptator means, b. passing the resulting stream to a scrubbing zone and effecting the contacting thereof with an aqueous slurry containing a calcium source, c. discharging a resulting scrubbed flue gas stream with reduced sulfur content from said scrubbing zone, d. also withdrawing from said scrubbing zone at least a part of the bottom slurry containing resulting calcium sulfite, combining an acid with said bottoms slurry to provide a low pH for said slurry, and passing such calcium sulfite-containing slurry to a separate ozonation zone, e. passing an ozone-containing gaseous stream into contact with the slurry material in said ozonation zone to effect a conversion of a major portion of the calcium sulfite in the bottoms slurry to calcium sulfate, at least a portion of the ozone-containing gaseous stream being passed to said ozonation zone being received from an ozone-containing stream discharged from said electrostatic precipitator means, and f. withdrawing a resulting calcium sulfate-containing sludge from said ozonation zone.
Claim 2
Independent Claim
204 words
A method for effecting the calcium slurry scrubbing and desulfurizing of a sulfur-containing flue gas stream in a manner to minimize the bulk of resulting calcium-sulfur compounds, which comprises the steps of: a. substantially removing extrained particulates from the flue gas stream by an electrostatic preciptator means, b. passing the resulting stream to a scrubbing zone and effecting the contacting thereof with an aqueous slurry containing a calcium source, c. discharging a resulting scrubbed flue gas stream with reduced sulfur content from said scrubbing zone, d. also withdrawing from said scrubbing zone at least a part of the bottom slurry containing resulting calcium sulfite, combining an acid with said bottoms slurry to provide a low pH for said slurry, and passing such calcium sulfite-containing slurry to a separate ozonation zone, e. passing an ozone-containing gaseous stream into contact with the slurry material in said ozonation zone to effect a conversion of a major portion of the calcium sulfite in the bottoms slurry to calcium sulfate, at least a portion of the ozone-containing gaseous stream being passed to said ozonation zone being received from an ozone-containing stream discharged from said electrostatic precipitator means, and f. withdrawing a resulting calcium sulfate-containing sludge from said ozonation zone.
Claim 3
Dependent Claim
21 words
The method of claim 1 still further characterized in that said acid introduced into the bottoms slurry stream is sulfuric acid.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |