US4935393A
Expired / Lapsed
US
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Process for catalytic reduction of nitrogen oxides
Assignee: Kali Chemie AG
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Filing: 1987-10-05
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Granted: 1990-06-19
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Expires: 2007-10-05
Abstract
Abstract A process for catalytically reducing nitrogen oxides in an exhaust gas such as a combustion gas and a catalyst suitable for use therein. The catalyst comprises a zeolite Y which has been ion exchanged with lithium ions and/or rare earth metal ions, and may be dispersed in an amorphous oxide gel matrix.
Inventors
- 👤 Norbert Schwetje
- 👤 Dieter Kipping
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:27
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/08; B01J29/10; B01J29/12; B01J29/126; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
136 words
A catalyst suitable for selective reduction of nitrogen oxides (NO x ) in exhaust gases, said catalyst comprising: (a) 10 to 95% by weight zeolite Y which has been subjected to ion exchange with at least one ion selected from the group consisting of lithium ion and rare earth metal ions; (b) 4.95 to 89.95% by weight amorphous oxide gel matrix formed of at least one oxide selected from the group consisting of SiO 2 and oxides of the metals aluminum, magnesium, calcium, titanium and zirconium or binary or ternary mixtures of such oxides; and (c) 0.05 to 15% by weight of a phase having hydrogen binding capability selected from the group consisting of transition metals and compounds of transition metals, whereby the sum of the components (a) through (c) amounts in each case to 100%.
Claim 2
Dependent Claim
136 words
A catalyst suitable for selective reduction of nitrogen oxides (NO x ) in exhaust gases, said catalyst comprising: (a) 10 to 95% by weight zeolite Y which has been subjected to ion exchange with at least one ion selected from the group consisting of lithium ion and rare earth metal ions; (b) 4.95 to 89.95% by weight amorphous oxide gel matrix formed of at least one oxide selected from the group consisting of SiO 2 and oxides of the metals aluminum, magnesium, calcium, titanium and zirconium or binary or ternary mixtures of such oxides; and (c) 0.05 to 15% by weight of a phase having hydrogen binding capability selected from the group consisting of transition metals and compounds of transition metals, whereby the sum of the components (a) through (c) amounts in each case to 100%.
Claim 3
Dependent Claim
36 words
A catalyst as recited in claim 1, wherein said transition metal is selected from the group of transition metals having the atomic numbers 22 to 28, 40 to 46, 57 to 71 and 72 to 78.
Claim 4
Dependent Claim
30 words
A catalyst as recited in claim 2, wherein said transition metal is selected from the group of transition metals having the atomic numbers 26 to 28 and 57 to 71.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |