US4770863A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the reduction of nitrogen oxides in an effluent
Assignee: Fuel Tech Inc
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Filing: 1987-02-13
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Granted: 1988-09-13
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Expires: 2007-02-13
Abstract
Abstract A process for the reduction of nitrogen oxides from an effluent from the combustion of a carbonaceous fuel is presented. More particularly, this process comprises injecting into the effluent droplets of a mixture comprising ammonia and an enhancer selected from the group consisting of hexamethylenetetraamine, a lower carbon alcohol, sugar, furfural, furfural derivatives, a hydroxyl amino hydrocarbon, an amino acid, a protein-containing composition, mixtures of ortho-, meta-, and para-methyl phenols, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and mixtures thereof, 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
2026-10-27 23:56
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: 21
Claim 1
Independent Claim
134 words
A process for reducing the concentration of nitrogen oxides in an effluent from the combustion of a carbonaceous fuel, which process comprises injecting into the effluent ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, a lower carbon alcohol, a hydroxyl amino hydrocarbon, sugar, furfural, furfural derivatives, an amino acid, a protein-containing composition, mixtures of ortho-, meta-, and para-methyl phenols, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and mixtures thereof, at an effluent temperature above about 1300° F. and a molar ratio of nitrogen in the ammonia and enhancer to the baseline nitrogen oxides level of about 1:5 to about 6:1 wherein the excess of oxygen in the effluent is no greater than about 6%.
Claim 2
Dependent Claim
134 words
A process for reducing the concentration of nitrogen oxides in an effluent from the combustion of a carbonaceous fuel, which process comprises injecting into the effluent ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, a lower carbon alcohol, a hydroxyl amino hydrocarbon, sugar, furfural, furfural derivatives, an amino acid, a protein-containing composition, mixtures of ortho-, meta-, and para-methyl phenols, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and mixtures thereof, at an effluent temperature above about 1300° F. and a molar ratio of nitrogen in the ammonia and enhancer to the baseline nitrogen oxides level of about 1:5 to about 6:1 wherein the excess of oxygen in the effluent is no greater than about 6%.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein said enhancer is present in said mixture in a weight ratio of enhancer to ammonia of about 1:5 to about 4:1.
Claim 4
Dependent Claim
10 words
The process of claim 2 wherein said enhancer comprises hexamethylenetetramine.
Claim 5
Dependent Claim
13 words
The process of claim 2 wherein said enhancer comprises a lower carbon alcohol.
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein said lower carbon alcohol comprises ethylene glycol.
Claim 7
Dependent Claim
10 words
The process of claim 2 wherein said enhancer comprises sugar.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein said mixture comprises an aqueous solution.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the excess of oxygen in the effluent is about 1% to about 6%.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein said mixture is injected into the effluent at a temperature of about 1300° F. to about 1700° F.
Claim 11
Dependent Claim
89 words
A process for reducing the concentration of nitrogen oxides in an oxygen-rich effluent containing less than about 6% excess of oxygen, which process comprises injecting into the effluent droplets of an aqueous mixture of ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, sugar, furfural, a lower carbon alcohol, and mixtures thereof, wherein the temperature of the effluent is about 1300° F. to about 1700° F. and the molar ratio of nitrogen in said mixture to the baseline nitrogen oxides level is about 1:5 to about 6:1.
Claim 12
Dependent Claim
89 words
A process for reducing the concentration of nitrogen oxides in an oxygen-rich effluent containing less than about 6% excess of oxygen, which process comprises injecting into the effluent droplets of an aqueous mixture of ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, sugar, furfural, a lower carbon alcohol, and mixtures thereof, wherein the temperature of the effluent is about 1300° F. to about 1700° F. and the molar ratio of nitrogen in said mixture to the baseline nitrogen oxides level is about 1:5 to about 6:1.
Claim 13
Dependent Claim
27 words
The process of claim 10 wherein said enhancer is present in said mixture in a weight ratio of enhancer to ammonia of about 1:5 to about 4:1.
Claim 14
Dependent Claim
10 words
The process of claim 11 wherein said enhancer comprises hexamethylenetetraamine.
Claim 15
Dependent Claim
10 words
The process of claim 11 wherein said enhancer comprises sugar.
Claim 16
Dependent Claim
10 words
The process of claim 13 wherein said sugar comprises sucrose.
Claim 17
Dependent Claim
13 words
The process of claim 11 wherein said enhancer comprises a lower carbon alcohol.
Claim 18
Dependent Claim
13 words
The process of claim 15 wherein said lower carbon alcohol comprises ethylene glycol.
Claim 19
Dependent Claim
12 words
The process of claim 10 wherein said mixture comprises an aqueous solution.
Claim 20
Dependent Claim
19 words
The process of claim 10 wherein the excess of oxygen in the effluent is about 1% to about 6%.
Claim 21
Dependent Claim
10 words
The process of claim 11 wherein said enhancer comprises furfural.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |