US3953575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Iron oxide sorbents for regenerative sorption of Nox
Assignee: American Gas Association Inc
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Filing: 1973-11-21
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Granted: 1976-04-27
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Expires: 1993-11-21
Abstract
Abstract The use of iron oxide sorbents to remove oxides of nitrogen (NO x ) from gaseous mixtures containing small amounts of NO x such as the exhaust from an internal combustion engine or flue gases, without interference from carbon oxides or water vapor and thermally regenerable at relatively low temperatures, are disclosed. A preferred sorbent is supported ferric oxide for sorption of NO x from gaseous mixtures containing oxygen. Ferrous or ferrosoferric oxide sorbents are also suitable in the presence or absence of oxygen.
Inventors
- 👤 Dimitri Gidaspow
- 👤 Linus Leung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:53
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
A process for the removal of oxides of nitrogen present in small amounts in a gas stream selected from a flue gas stream or an internal combustion engine exhaust stream containing at least 1% oxygen which comprises: i. contacting, in a sorption step the gas stream with a ferric oxide sorbent supported on a porous alumina support under conditions sufficient to sorb oxides of nitrogen on said sorbent including a temperature of about 0°C to about 350°C, ii. terminating said sorption step; iii. thermally regenerating said sorbent at a temperature of about 400°C to about 500°C with an inert gas stream to remove the sorbed oxides of nitrogen and to produce a gas stream containing the sorbed oxides of nitrogen; and iv. repeating the sorption step.
Claim 2
Dependent Claim
126 words
A process for the removal of oxides of nitrogen present in small amounts in a gas stream selected from a flue gas stream or an internal combustion engine exhaust stream containing at least 1% oxygen which comprises: i. contacting, in a sorption step the gas stream with a ferric oxide sorbent supported on a porous alumina support under conditions sufficient to sorb oxides of nitrogen on said sorbent including a temperature of about 0°C to about 350°C, ii. terminating said sorption step; iii. thermally regenerating said sorbent at a temperature of about 400°C to about 500°C with an inert gas stream to remove the sorbed oxides of nitrogen and to produce a gas stream containing the sorbed oxides of nitrogen; and iv. repeating the sorption step.
Claim 3
Dependent Claim
19 words
A process as in claim 1 wherein said gas stream contains about 50 to 1000 ppm oxides of nitrogen.
Claim 4
Dependent Claim
18 words
A process as in claim 1 wherein said sorbent contains about 5 to 10% by weight iron oxide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |