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US4289653A
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Comulled silica-alumina base denitrification catalyst
Assignee: Chevron USA Inc
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Filing: 1979-11-05
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Granted: 1981-09-15
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Expires: 1999-11-05
Abstract
Abstract An extruded silica-alumina base catalyst is prepared by cogelling a silica sol solution containing aluminum and having a pH in the range of about 1-3. The cogelled silica-alumina is peptized to form an extrudable dough and may be mulled with Group VI-B and Group VIII metals to prepare a denitrification catalyst extrudable composition.
Inventors
- 👤 Joseph Jaffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:54
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/12; B01J23/00; B01J23/70; B01J23/76; B01J23/84; B01J23/85; C; C10; C10G; C10G45/00; C10G45/02; C10G45/04; C10G45/06; C10G45/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
144 words
An extruded silica-alumina catalyst prepared by the method which consists essentially of the following steps: mixing a sodium silicate solution with an aqueous aluminum sulfate solution and sulfuric acid to form an acidified silica sol in an alumina salt solution having a pH in the range of about 1 to 3; adding sufficient ammonium hydroxide to said acidified silica sol in the aluminum salt solution to form a cogelled mass of silica and alumina under substantially constant pH conditions and at a pH of at least 4; adding additional ammonium hydroxide to the cogelled mass to obtain a pH in the range of 7.5 to 8.5; washing the cogelled mass; mulling the cogelled mass with a peptizing agent, a Group VI-B metal compound and a Group VIII metal compound to form an extrudable dough; extruding said dough; and drying and calcining the extruded dough.
Claim 2
Dependent Claim
144 words
An extruded silica-alumina catalyst prepared by the method which consists essentially of the following steps: mixing a sodium silicate solution with an aqueous aluminum sulfate solution and sulfuric acid to form an acidified silica sol in an alumina salt solution having a pH in the range of about 1 to 3; adding sufficient ammonium hydroxide to said acidified silica sol in the aluminum salt solution to form a cogelled mass of silica and alumina under substantially constant pH conditions and at a pH of at least 4; adding additional ammonium hydroxide to the cogelled mass to obtain a pH in the range of 7.5 to 8.5; washing the cogelled mass; mulling the cogelled mass with a peptizing agent, a Group VI-B metal compound and a Group VIII metal compound to form an extrudable dough; extruding said dough; and drying and calcining the extruded dough.
Claim 3
Dependent Claim
27 words
An extruded silica-alumina catalyst as recited in claim 1, wherein said Group VI-B metal compound is ammonium heptamolybdate and said Group VIII metal compound is nickel carbonate.
Claim 4
Dependent Claim
16 words
An extruded silica-alumina catalyst as recited in claim 1, wherein said peptizing agent is acetic acid.
Claim 5
Dependent Claim
25 words
An extruded silica-alumina catalyst as recited in claim 1, prepared by the method further comprising spray-drying the washed cogelled mass prior to the mulling step.
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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |