US4645652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for scrubbing sulfur oxides and nitrogen oxides in a flue gas duct
Assignee: Marsulex Environmental Technologies LLC
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Filing: 1985-11-29
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Granted: 1987-02-24
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Expires: 2005-11-29
Abstract
Abstract SO x and NO x are scrubbed from a flue gas stream by first introducing dry sorbent for NO x removal with controlled humidification downstream for SO x removal. The SO x and NO x removal may be performed in a flue gas duct to minimize the cost for retrofit applications.
Inventors
- 👤 Shiro G. Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:36
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/60; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
112 words
A method of scrubbing nitrogen oxides and sulfur oxides from flue gas comprising the steps of: dispersing a dry alkaline powder into a flue gas duct carrying flue gas from a boiler and air preheater to remove nitrogen oxides and some sulfur oxides at a temperature of 250° to 500° F.; introducing an aqueous alkali slurry into the flue gas duct at a point downstream of the dry sorbent injection point, said aqueous alkali slurry simultaneously drying and absorbing additional sulfur oxides from the flue gas, directing the flue gas to a particulate collection device to remove the dry partially spend sorbent and flyash; and directing the flue gas to a stack.
Claim 2
Independent Claim
112 words
A method of scrubbing nitrogen oxides and sulfur oxides from flue gas comprising the steps of: dispersing a dry alkaline powder into a flue gas duct carrying flue gas from a boiler and air preheater to remove nitrogen oxides and some sulfur oxides at a temperature of 250° to 500° F.; introducing an aqueous alkali slurry into the flue gas duct at a point downstream of the dry sorbent injection point, said aqueous alkali slurry simultaneously drying and absorbing additional sulfur oxides from the flue gas, directing the flue gas to a particulate collection device to remove the dry partially spend sorbent and flyash; and directing the flue gas to a stack.
Claim 3
Dependent Claim
41 words
The method of claim 1 further comprising the steps of: recycling a portion of the dry partially spent sorbent and flyash as alkaline powder and recycling a portion of the dry partially spend sorbent and flyash as an aqueous alkali slurry.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein said dry alkaline powder comprises lime, and partially spent sorbent and flyash removed as a by-product of the process.
Claim 5
Dependent Claim
26 words
The method of claim 2 wherein said dry alkaline powder comprises alkali carbonate, and partially spent sorbent and flyash removed as a by-product of the process.
References Cited (Backward Citations)
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Cited
US4081513A
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US4324770A
Cited
US4309393A
Cited
US4519995A
Cited
US4559211A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |