Patent US4735930A successfully refreshed from Google Patents.
US4735930A
Expired / Lapsed
US
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Catalyst for the reduction of oxides of nitrogen
Assignee: Saint Gobain Abrasives Inc
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Filing: 1986-02-18
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Granted: 1988-04-05
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Expires: 2006-02-18
Abstract
Abstract A catalyst for the selective reduction of nitrogen oxides to nitrogen in the presence of ammonia in the form of composite bodies formed from a mixture of zirconia (5 to 50% by weight), a zeolite (50 to 90%), a bond material (0 to 30%), and, optionally, a promoter selected from oxides of vanadium and copper in the amount of at least 0.1% by weight.
Inventors
- 👤 William H. Gerdes
- 👤 Charles Lim
- 👤 Thomas Szymanski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:11
CPC Classifications
B; B01; B01J; B01J20/00; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; B01J29/00; B01J29/04; B01J29/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
74 words
A catalyst for the selective reduction of NOx to nitrogen in the presence of ammonia, said catalyst being a shaped coformed mixture of 5 to 50% by weight of zirconia starting material having a surface area of at least 10, preferably greater than 50 square meters per gram and containing at least 50 to 90% of one or more zeolites in the hydrogen or ammonium form and up to 30% of a bonding agent.
Claim 2
Dependent Claim
74 words
A catalyst for the selective reduction of NOx to nitrogen in the presence of ammonia, said catalyst being a shaped coformed mixture of 5 to 50% by weight of zirconia starting material having a surface area of at least 10, preferably greater than 50 square meters per gram and containing at least 50 to 90% of one or more zeolites in the hydrogen or ammonium form and up to 30% of a bonding agent.
Claim 3
Dependent Claim
27 words
A catalyst as in claim 1 containing at least 0.1% by weight of a promoter selected from the group consisting of oxides of vanadium and of copper.
Claim 4
Dependent Claim
16 words
A catalyst as in claim 1 in which said zeolite contains a major portion of clinoptilolite.
Claim 5
Dependent Claim
12 words
A catalyst as in claim 1 in which said zeolite is clinoptilolite.
Claim 6
Dependent Claim
19 words
A catalyst as in claim 1 in which the zirconia is derived from the hydrolysis of a zirconyl salt.
Claim 7
Dependent Claim
25 words
A catalyst as in claim 1 in which said zirconia is derived from the hydrolysis of one or more zirconium salts to ZrO 2 .
Claim 8
Dependent Claim
21 words
A catalyst as in claim 1 in the form of rings, spheres, cross partition rings, stars, saddles, aggregates, honeycombs, or pellets.
Claim 9
Dependent Claim
27 words
A catalyst as in claim 4 containing at least 0.1% by elemental weight of a promoter selected from the group of oxides of vanadium or of copper.
Claim 10
Dependent Claim
20 words
A catalyst as in claim 1 in which the active catalyst composition is coated onto a metal or ceramic support.
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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) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |