US4877591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the reduction of nitrogen oxides in an effluent using sugar
Assignee: Fuel Tech Inc
•
Filing: 1987-03-13
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Granted: 1989-10-31
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Expires: 2007-03-13
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 injecting a treatment agent comprising sugar into an effluent under conditions effective to reduce the concentration of nitrogen oxides in the effluent.
Inventors
- 👤 William R. Epperly
- 👤 James C. Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:47
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; Y; Y02; Y02W; Y02W10/00; Y02W10/30; Y02W10/37
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
59 words
A process for the reduction of the concentration of nitrogen oxides in the oxygen-rich effluent from the combustion of a carbonaceous fuel, the process comprising injecting a treatment agent which comprises urea and sugar into an effluent having a temperature of greater than about 1300° F. under conditions effective to reduce the concentration of nitrogen oxides in the effluent.
Claim 2
Dependent Claim
59 words
A process for the reduction of the concentration of nitrogen oxides in the oxygen-rich effluent from the combustion of a carbonaceous fuel, the process comprising injecting a treatment agent which comprises urea and sugar into an effluent having a temperature of greater than about 1300° F. under conditions effective to reduce the concentration of nitrogen oxides in the effluent.
Claim 3
Dependent Claim
10 words
The process of claim 1 wherein said sugar comprises sucrose.
Claim 4
Dependent Claim
18 words
The process of claim 2 wherein the effluent is at a temperature of greater than about 1450° F.
Claim 5
Dependent Claim
16 words
The process of claim 2 wherein the temperature of the effluent is below about 2000° F.
Claim 6
Dependent Claim
12 words
The process of claim 2 wherein said treatment agent is in solution.
Claim 7
Dependent Claim
12 words
The process of claim 5 wherein said solution comprises an aqueous solution.
Claim 8
Dependent Claim
23 words
The process of claim 6 wherein urea is present in said solution in an amount of about 2% to about 60% by weight.
Claim 9
Dependent Claim
23 words
The process of claim 7 wherein sugar is present in said solution in an amount of about 0.5% to about 25% by weight.
Claim 10
Dependent Claim
38 words
The process of claim 3 wherein said treatment agent is injected into the effluent at a molar ratio of the nitrogen contained in said treatment agent to the baseline nitrogen oxides level of about 1:5 to about 10:1.
Claim 11
Dependent Claim
24 words
The process of claim 9 wherein the molar ratio of treatment agent nitrogen to baseline nitrogen oxides level is about 1:3 to about 5:1.
Claim 12
Dependent Claim
21 words
The process of claim 1 wherein said effluent has an excess of oxygen of no greater than about 12% by volume.
Claim 13
Dependent Claim
121 words
A process for the reduction of the concentration of nitrogen oxides in the oxygen-rich effluent from the combustion of a carbonaceous fuel, the process comprising injecting a treatment agent which comprises an aqueous solution of about 2% to about 60% urea by weight and about 0.5% to about 25% sugar by weight into an effluent having an excess of oxygen of about 1% to about 6% by volume and a temperature of about 1450° F. to about 1900° F. in an amount sufficient to provide a molar ratio of the nitrogen contained in said treatment agent to the baseline nitrogen oxides level of about 1:3 to about 5:1 under conditions effective to reduce the concentration of nitrogen oxides in the effluent.
Claim 14
Dependent Claim
121 words
A process for the reduction of the concentration of nitrogen oxides in the oxygen-rich effluent from the combustion of a carbonaceous fuel, the process comprising injecting a treatment agent which comprises an aqueous solution of about 2% to about 60% urea by weight and about 0.5% to about 25% sugar by weight into an effluent having an excess of oxygen of about 1% to about 6% by volume and a temperature of about 1450° F. to about 1900° F. in an amount sufficient to provide a molar ratio of the nitrogen contained in said treatment agent to the baseline nitrogen oxides level of about 1:3 to about 5:1 under conditions effective to reduce the concentration of nitrogen oxides in the effluent.
References Cited (Backward Citations)
US4212853A
Cited
US4350669A
Cited
US4400362A
Cited
US4751065A
Cited
US4731233A
Cited
US4770863A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |