US4388283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
SO2 removal
Assignee: Bechtel Group Inc
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Filing: 1982-02-18
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Granted: 1983-06-14
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Expires: 2002-02-18
Abstract
Abstract Improved methods are provided for the efficient and economic removal of sulfur dioxide from gases, which comprise contacting the gas with neutralizing values obtained from Type S hydrated lime, i.e. calcined dolomite, slaked with water under elevated temperature and pressure. The Type S hydrated dolomitic lime may be used in conjunction with a wet scrubber to provide base and neutralizing magnesium values, in a spray dryer or dry scrubber, or directly introduced into the boiler. The use of Type S hydrated dolomitic lime greatly enhances the efficiency of sulfur dioxide removal, providing for enhanced utilization of base values and more rapid rate of reaction.
Inventors
- 👤 Jack Z. Abrams
- 👤 Robert M. Sherwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:36
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
125 words
A method for removing sulfur dioxide from sulfur dioxide containing flue gas resulting from the burning of sulfur containing fossil fuel, said method comprising: in a spray dryer introducing into a stream of said flue gas fine particles of an aqueous dispersion of Type S hydrated dolomitic lime in an amount sufficient to remove at least about 70% of the sulfur dioxide present in said flue gas, while reducing the temperature of said flue gas from 240°-350° F. to not lower than a temperature in the range of about 145° to 165° F., wherein the amount of the aqueous dispersion introduced is less than the amount which would result in condensation at said lower temperature; and separating the resulting substantially dry particles from the effluent.
Claim 2
Independent Claim
125 words
A method for removing sulfur dioxide from sulfur dioxide containing flue gas resulting from the burning of sulfur containing fossil fuel, said method comprising: in a spray dryer introducing into a stream of said flue gas fine particles of an aqueous dispersion of Type S hydrated dolomitic lime in an amount sufficient to remove at least about 70% of the sulfur dioxide present in said flue gas, while reducing the temperature of said flue gas from 240°-350° F. to not lower than a temperature in the range of about 145° to 165° F., wherein the amount of the aqueous dispersion introduced is less than the amount which would result in condensation at said lower temperature; and separating the resulting substantially dry particles from the effluent.
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein the sulfur dioxide content of said flue gas is in the range of about 0.04%-0.4% by volume.
Claim 4
Dependent Claim
32 words
A method according to any of claim 1 or 2, wherein said Type S hydrated dolomitic lime is in a stoichiometric ratio to said sulfur dioxide in the range of about 1.2-1.5.
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) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |