US4080426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction of nitric oxide using catalysts pretreated with selenium
Assignee: New England Power Service Co
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Filing: 1977-04-11
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Granted: 1978-03-21
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Expires: 1997-04-11
Abstract
Abstract Base metal catalysts are pretreated with selenium, sulfur or sulfur compounds. Subsequently, a gaseous stream comprising nitric oxide, oxygen and ammonia is passed over the pretreated catalysts. The nitric oxide is reduced to nitrogen and no nitrous oxide is formed.
Inventors
- 👤 James R. Kittrell
- 👤 Donald L. Herman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:53
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; Y; Y02; Y02C; Y02C20/00; Y02C20/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
137 words
A method for the catalytic reduction of nitric oxide which includes a. blending ammonia with a gaseous stream comprising nitric oxide and oxygen, the ammonia added in an amount sufficient to react with the total amount of nitric oxide in a stream to form a blended stream; b. placing the blended stream of step (a) in catalytic contact with a pretreated base metal catalyst at a temperature of between about 300° F. to 700° F. to reduce the nitric oxide to nitrogen while preventing the formation of nitrous oxide, the base metal catalyst selected from the group consisting of copper, vanadium, iron and molybdenum and combinations thereof, which catalyst has been pretreated by contact with a gaseous pretreatment stream containing selenium at a temperature of between about 400° F. to 900° F. to form the pretreated catalyst.
Claim 2
Independent Claim
137 words
A method for the catalytic reduction of nitric oxide which includes a. blending ammonia with a gaseous stream comprising nitric oxide and oxygen, the ammonia added in an amount sufficient to react with the total amount of nitric oxide in a stream to form a blended stream; b. placing the blended stream of step (a) in catalytic contact with a pretreated base metal catalyst at a temperature of between about 300° F. to 700° F. to reduce the nitric oxide to nitrogen while preventing the formation of nitrous oxide, the base metal catalyst selected from the group consisting of copper, vanadium, iron and molybdenum and combinations thereof, which catalyst has been pretreated by contact with a gaseous pretreatment stream containing selenium at a temperature of between about 400° F. to 900° F. to form the pretreated catalyst.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the base metal catalyst is selected from the group consiting of copper, vanadium and iron.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein said pretreatment stream comprises selenium and 2% hydrogen in helium.
References Cited (Backward Citations)
FR1271524A
Cited
US3864451A
Cited
US4018710A
Cited
US3981971A
Cited
US4002723A
Cited
DE2436683A1
Cited
US4043939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |