US4197285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneration of lime from sulfates for fluidized-bed combustion
Assignee: United States Department of Energy
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Filing: 1977-12-07
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Granted: 1980-04-08
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Expires: 1997-12-07
Abstract
Abstract In a fluidized-bed combustor the evolving sulfur oxides are reacted with CaO to form calcium sulfate which is then decomposed in the presence of carbonaceous material, such as the fly ash recovered from the combustion, at temperatures of about 900° to 1000° C., to regenerate lime. The regenerated lime is then recycled to the fluidized bed combustor to further react with the evolving sulfur oxides. The lime regenerated in this manner is quite effective in removing the sulfur oxides.
Inventors
- 👤 Ralph T. Yang
- 👤 Meyer Steinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:26
CPC Classifications
F; F23; F23C; F23C10/00; F23C10/002; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/508; B01J; B01J8/00; B01J8/18; B01J8/24; C; C01; C01F; C01F11/00; C01F11/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
A process for the regeneration of lime in the fluidized-bed combustion of coal comprising: (a) combusting coal containing sulfurous material in a fluidized-bed combustor forming SO 2 in the presence of fluidized bed particulates comprising CaO, wherein the CaO is reacted with the combustion SO 2 to form CaSO 4 ; (b) reacting the particulates comprising the CaSO 4 from the combustor, at a temperature from about 850° C. to about 1100° C., with solid carbonaceous material to form CaO wherein the carbonaceous material comprises fly ash recovered from fluidized-bed combustion; and (c) recycling the particulates comprising the regenerated CaO at substantially the temperature of step (b) to the fluidized bed combustor.
Claim 2
Dependent Claim
112 words
A process for the regeneration of lime in the fluidized-bed combustion of coal comprising: (a) combusting coal containing sulfurous material in a fluidized-bed combustor forming SO 2 in the presence of fluidized bed particulates comprising CaO, wherein the CaO is reacted with the combustion SO 2 to form CaSO 4 ; (b) reacting the particulates comprising the CaSO 4 from the combustor, at a temperature from about 850° C. to about 1100° C., with solid carbonaceous material to form CaO wherein the carbonaceous material comprises fly ash recovered from fluidized-bed combustion; and (c) recycling the particulates comprising the regenerated CaO at substantially the temperature of step (b) to the fluidized bed combustor.
Claim 3
Dependent Claim
15 words
The process of claim 1, wherein the reaction of step (b) is in a kiln.
Claim 4
Dependent Claim
20 words
The process of claim 1, wherein the pressure of the reaction of step (b) is from 1 to 10 atmospheres.
Claim 5
Dependent Claim
14 words
The process of claim 1, wherein the carbonaceous material is a finely divided solid.
Claim 6
Dependent Claim
40 words
The process of claim 1, further comprising, providing a flow of an oxygen-containing gas to react with carbon in the fly ash to maintain the reaction of step (b) at a temperature of from about 850° C. to 1100° C.
Claim 7
Dependent Claim
30 words
The process of claim 1, wherein the temperature of the particulates comprising CaO in step (b) is about the same as the temperature of the fluidized-bed combustion in step (a).
Claim 8
Dependent Claim
34 words
The process of claim 1, further comprising recovering the carbonaceous material as a finely divided solid, and then mixing the said solid with the solid particulates comprising CaSO 4 in the step (b) reaction.
Claim 9
Dependent Claim
16 words
The process of claim 1, wherein the fluidized-bed combustor is at 800° C. to 950° C.
Claim 10
Dependent Claim
21 words
The process of claim 2, wherein the fluidized-bed particulates of step (a) are fed directly to the kiln of step (b).
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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |