US4873066A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low temperature process for the reduction of nitrgen oxides in an effluent
Assignee: Fuel Tech Inc
•
Filing: 1989-02-08
•
Granted: 1989-10-10
•
Expires: 2009-02-08
Abstract
Abstract A process is presented for the reduction of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a treatment agent which comprises an ammonium salt selected from the group consisting of triammonium citrate and ammonium formate into an effluent at an effluent temperature of below 1300° F.
Inventors
- 👤 William R. Epperly
- 👤 James C. Sullivan
- 👤 Barry N. Sprague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:02
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; B01J; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00054; B01J2219/00056; B01J2219/00058
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
54 words
A process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel, the process comprising introducing a treatment agent which comprises an ammonium salt selected from the group consisting of triammonium citrate and ammonium formate into the effluent at an effluent temperature below 1300° F.
Claim 2
Dependent Claim
54 words
A process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel, the process comprising introducing a treatment agent which comprises an ammonium salt selected from the group consisting of triammonium citrate and ammonium formate into the effluent at an effluent temperature below 1300° F.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the temperature of the effluent is below about 1200° F.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein the temperature of the effluent is at least about 900° F.
Claim 5
Dependent Claim
37 words
The process of claim 1 wherein said treatment agent is introduced into the effluent at a molar ratio of the nitrogen contained in said treatment agent to the baseline nitrogen oxides level of 1:5 to about 10:1.
Claim 6
Dependent Claim
25 words
The process of claim 4 wherein the molar ratio of treatment agent nitrogen to the baseline nitrogen oxides level is about 1:3 to about 5:1.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein said treatment agent is in solution, in a mixture or in a dispersion.
Claim 8
Dependent Claim
13 words
The process of claim 6 wherein said treatment agent is in aqueous solution.
Claim 9
Dependent Claim
28 words
The process of claim 6 wherein said ammonium salt is present in said solution, mixture or dispersion in an amount of about 0.5% to about 50% by weight.
Claim 10
Dependent Claim
13 words
The process of claim 1 wherein the effluent comprises an excess of oxygen.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein the effluent has an excess of oxygen of no greater than about 20% by volume.
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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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |