US4070440A
Expired / Lapsed
US
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Method of reducing NOx present in an exhaust to harmless N2
Assignee: JFE Engineering Corp
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Filing: 1976-09-07
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Granted: 1978-01-24
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Expires: 1996-09-07
Abstract
Abstract A method for reducing NOx gas contained in an exhaust gas to harmless N2 gas with NH3 gas using an iron oxide catalyst, characterized in that said iron oxide catalyst comprises a substance consisting essentially of hematite crystals ( alpha -Fe2O3), and the peak intensity of X-rays diffracted on the (110) plane of the lattice of said crystal has a ratio of 0.6 to about 1.0 to that of X-rays diffracted on the (104) plane of said crystal lattice.
Inventors
- 👤 Sanseki Moriguchi
- 👤 Hiroshi Abe
- 👤 Joichi Takenaka
- 👤 Hideyuki Yoshikoshi
- 👤 Osamu Komatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:17
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01J; B01J23/00; B01J23/70; B01J23/74; B01J23/745
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
108 words
In the method for reducing NO x gas contained in an exhaust gas to N 2 gas wherein the exhaust gas is contacted with NH 3 gas and an iron oxide catalyst, the improvement wherein the catalyst consists essentially of a hematite iron ore modified from a goethite iron ore by preheating the goethite iron ore at a temperature of from 300° to 900° C., and having a ratio defined by the peak intensity of X-rays diffracted on the (110) plane of the lattice of the hematite crystals therein to that of X-rays diffracted on the (104) plane of said crystal lattice of from 0.6 to about 1.0.
Claim 2
Dependent Claim
108 words
In the method for reducing NO x gas contained in an exhaust gas to N 2 gas wherein the exhaust gas is contacted with NH 3 gas and an iron oxide catalyst, the improvement wherein the catalyst consists essentially of a hematite iron ore modified from a goethite iron ore by preheating the goethite iron ore at a temperature of from 300° to 900° C., and having a ratio defined by the peak intensity of X-rays diffracted on the (110) plane of the lattice of the hematite crystals therein to that of X-rays diffracted on the (104) plane of said crystal lattice of from 0.6 to about 1.0.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein said ratio is about 1.0
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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |