US5041272A
Expired / Lapsed
US
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Method for removing nitrogen oxides from exhaust gases
Assignee: Foundation for Biomedical Research and Innovation
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Filing: 1991-03-19
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Granted: 1991-08-20
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Expires: 2011-03-19
Abstract
Abstract A method for removing nitrogen oxides from exhaust gases containing oxygen and moisture, which comprises bringing the exhaust gas into contact with hydrogenated zeolite catalysts or hydrogenated zeolite catalysts impregnated with one or more kinds of metals selected from the group consisting of copper, zinc, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, palladium, platinum, and molybdenum, in the presence of organic compounds. The zeolite should be a zeolite having a silica/alumina ratio of 5 or above. The zeolite may be any one of zeolite of Y type, zeolite of L type, zeolite of offretite-erionite mixed crystal type, zeolite of ferrierite type, zeolite of mordenite type, zeolite of clinoptilolite type, and zeolite of ZSM-5 type.
Inventors
- 👤 Takaaki Tamura
- 👤 Mikio Kumagai
- 👤 Akimichi Katsuta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:45
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/061; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01D2251/00; B01D2251/20; B01D2251/21; B01D2255/00; B01D2255/10; B01D2255/102; B01D2255/20; B01D2255/207; B01D2255/50; B01D2258/00; B01D2258/01; B01D2258/012; F; F02; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
134 words
A method for removing nitrogen oxides from exhaust gas containing oxygen and moisture, comprising the step of bringing the exhaust gas into contact with a hydrogenated zeolite catalyst selected from the group consisting of hydrogenated synthetic zeolites, hydrogenated natural zeolites, hydrogenated synthetic zeolites impregnated with one or more metals selected from the group consisting of copper, zinc, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, palladium, platinum and molybdenum, and hydrogenated natural zeolites impregnated with one or more metals selected from the group consisting of copper, zinc, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, palladium, platinum, and molybdenum, in the presence of organic compounds as a reducing agent selected from the group consisting of hydrocarbons, alcohols, ketones, or ether, at a temperature sufficient to cause reaction between said hydrogenated zeolite catalyst and said nitrogen oxides.
Claim 2
Independent Claim
134 words
A method for removing nitrogen oxides from exhaust gas containing oxygen and moisture, comprising the step of bringing the exhaust gas into contact with a hydrogenated zeolite catalyst selected from the group consisting of hydrogenated synthetic zeolites, hydrogenated natural zeolites, hydrogenated synthetic zeolites impregnated with one or more metals selected from the group consisting of copper, zinc, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, palladium, platinum and molybdenum, and hydrogenated natural zeolites impregnated with one or more metals selected from the group consisting of copper, zinc, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, palladium, platinum, and molybdenum, in the presence of organic compounds as a reducing agent selected from the group consisting of hydrocarbons, alcohols, ketones, or ether, at a temperature sufficient to cause reaction between said hydrogenated zeolite catalyst and said nitrogen oxides.
Claim 3
Dependent Claim
29 words
A method for removing nitrogen oxides from exhaust gas as claimed in claim 1, wherein the zeolite catalyst is a zeolite having a silica/alumina ratio of 5 or above.
Claim 4
Dependent Claim
57 words
A method for removing nitrogen oxides from exhaust gas as claimed in claim 1 or claim 2, wherein the hydrogenated zeolite catalyst is any one of zeolite of Y type, zeolite of L type, zeolite of offretite-erionite mixed crystal type, zeolite of ferrierite type, zeolite of mordenite type, zeolite of clinoptilolite type, and zeolite of ZSM-5 type.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-08-19 | 1995-02-18 | 1995-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-19 | 1999-02-18 | 1999-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-19 | 2003-02-18 | 2003-08-20 | $7700.00 | Window Closed / Lapsed |