US3746498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reducing no{11 {11 emissions by additive injection
Assignee: Combustion Engineering Inc
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Filing: 1972-01-24
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Granted: 1973-07-17
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Expires: 1992-01-24
Abstract
Abstract The nitrogen oxides formed during combustion processes are reduced by injecting materials into a fuel-rich combustion zone. These additives decompose to produce reducing agents such as hydrogen and carbon monoxide which in turn react with the nitrogen oxides to produce nitrogen. The additives may comprise formates and oxalates such as sodium formate and sodium oxalate. The carbonates which are formed are also useful to reduce sulfur oxide pollution.
Inventors
- 👤 M Stengel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:50
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
20 words
A method as recited in claim 1 wherein said additive is selected from the group consisting of formates and oxalates.
Claim 2
Dependent Claim
27 words
A method as recited in claim 2 wherein said formates and oxalates are selected from the group consisting of sodium, ammonium, magnesium, and calcium formates and oxalates.
Claim 3
Dependent Claim
28 words
A method as recited in claim 1 wherein said first stage combustion air comprises between about 80 and 95 percent of the theoretical air required for complete combustion.
Claim 4
Dependent Claim
30 words
A method as recited in claim 1 wherein said additive comprises a formate selected from the group consisting of calcium, barium, manganese, potassium, zinc, lithium, ammonium, cadmium and sodium formate.
Claim 5
Dependent Claim
31 words
A method as recited in claim 1 wherein said additive comprises an oxalate selected from the group consisting of iron, magnesium, calcium, barium, manganese, zinc, lithium, ammonium, cadmium and sodium oxalate.
References Cited (Backward Citations)
US3048131A
Cited
GB942055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |