Patent US4848995A successfully refreshed from Google Patents.
US4848995A
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Removal of sulfur oxides from flue gas
Assignee: Shell USA Inc
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Filing: 1988-02-05
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Granted: 1989-07-18
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Expires: 2008-02-05
Abstract
Abstract A method of removing sulfur oxides from flue gas produced by the combustion of a fuel to produce a flue gas containing sulfur oxides and water comprising contacting the moist flue gas with hydrated alkaline earth metal hydroxide particles having a temperature sufficiently low to condense the water vapor present in the flue gas onto the particles and recovering a flue gas reduced in sulfur oxides.
Inventors
- 👤 Norman C. Samish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:21
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; Y; Y10; Y10S; Y10S62/00; Y10S62/922
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
A method of removing sulfur oxides from flue gas produced by the combustion of a fuel to produce a flue gas containing sulfur oxides and water vapor comprising contacting the moist flue gas with particles consisting essentially of hydrated alkaline earth metal hydroxide said particles having a temperature sufficiently low to condense the water vapor present in the flue gas onto the particles, the condensed water dissolving the surface oxides contained in the flue gas forming acid which subsequently reacts with the hydrate particles forming alkaline earth metal sulfur compounds, removing the sulfur compounds and excess particles and recovering a flue gas reduced in sulfur oxides.
Claim 2
Independent Claim
106 words
A method of removing sulfur oxides from flue gas produced by the combustion of a fuel to produce a flue gas containing sulfur oxides and water vapor comprising contacting the moist flue gas with particles consisting essentially of hydrated alkaline earth metal hydroxide said particles having a temperature sufficiently low to condense the water vapor present in the flue gas onto the particles, the condensed water dissolving the surface oxides contained in the flue gas forming acid which subsequently reacts with the hydrate particles forming alkaline earth metal sulfur compounds, removing the sulfur compounds and excess particles and recovering a flue gas reduced in sulfur oxides.
Claim 3
Dependent Claim
20 words
A process according to claim 1 wherein the alkaline earth metal hydroxide is calcium hydroxide, magnesium hydroxide or mixtures thereof.
Claim 4
Dependent Claim
15 words
A process according to claim 2 wherein the alkaline earth metal hydroxide is calcium hydroxide.
Claim 5
Dependent Claim
19 words
A process according to claim 1 wherein the hydrate is cooled prior to injection into the moist flue gases.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the hydrate is cooled by injecting hydrate particles and liquid nitrogen essentially simultaneously into the moist flue gases.
Claim 7
Dependent Claim
20 words
A process according to claim 1 wherein the moist flue gas has a temperature of 270° F. to 330° F.
Claim 8
Dependent Claim
16 words
A process according to claim 1 wherein the temperature of the particles is below 100° F.
Claim 9
Dependent Claim
28 words
A process according to claim 2 wherein the moist flue gas has a temperature of 260° F. to 400° F. and the particles temperature is below 100° F.
Claim 10
Dependent Claim
11 words
A process according to claim 8 wherein calcium hydroxide is used.
Claim 11
Dependent Claim
15 words
A process according to claim 9 wherein liquid nitrogen is used to cool the particles.
References Cited (Backward Citations)
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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) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |