US5085840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the reduction of nitrogen oxides contained in exhaust gases
Assignee: Bayer AG
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Filing: 1991-01-28
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Granted: 1992-02-04
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Expires: 2011-01-28
Abstract
Abstract A process for the reduction of nitrogen oxides in flue gases and engine exhaust gases is improved by contacting the gases with a zeolite catalyst containing oxides of the transition elements from Periods 4, 5 and 6 of the Periodic Table of Elements or oxides of the rare earths. In particular, faujasite zeolites, mordenites and SiO2-rich zeolites are preferred.
Inventors
- 👤 Wolfgang Held
- 👤 Axel Konig
- 👤 Lothar Puppe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:20
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; B01J29/42; B01J29/46; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; F; F01; F01N; F01N13/00; F01N13/009; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2067; B01D2255/00; B01D2255/20; B01D2255/207; B01D2255/20761; B01D2255/50; F01N2370/00; F01N2370/02; F01N2370/04; F01N2610/00; F01N2610/02; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N3/208; F02; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
67 words
In an improved process for the reduction of nitrogen oxides in engine exhaust gases under oxidizing conditions by contacting the gases with urea and a zeolite catalyst, the improvement comprises contacting the gases with a zeolitic catalyst containing 0.1 to 20% by weight of oxides of the transition elements of Periods 4, 5 and 6 of the Periodic Table of Elements or oxides of the rare earths.
Claim 2
Dependent Claim
67 words
In an improved process for the reduction of nitrogen oxides in engine exhaust gases under oxidizing conditions by contacting the gases with urea and a zeolite catalyst, the improvement comprises contacting the gases with a zeolitic catalyst containing 0.1 to 20% by weight of oxides of the transition elements of Periods 4, 5 and 6 of the Periodic Table of Elements or oxides of the rare earths.
Claim 3
Dependent Claim
67 words
The process according to claim 1 wherein said oxides are at least one of TiO 2 , V 2 O 5 , Cr 2 O 3 , MnO 2 , Fe 2 O 3 , CoO, NiO, CuO, Y 2 O 3 , ZrO 2 , Nb 2 O 5 , MoO 3 , La 2 O 3 , Ce 2 O 3 or WO 3 .
Claim 4
Dependent Claim
15 words
The process according to claim 1 wherein the gases are internal combustion engine exhaust gases.
Claim 5
Dependent Claim
47 words
The process according to claim 3 wherein the amount of urea is in relation to speed and load values of the engine producing the gases treated whereby at any given time approximately the amount of the urea required for complete reduction of the nitrogen oxides is added.
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) | 1995-02-03 | 1995-08-05 | 1996-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-03 | 1999-08-05 | 2000-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-03 | 2003-08-05 | 2004-02-04 | $7700.00 | Window Closed / Lapsed |