Patent US4184980A successfully refreshed from Google Patents.
US4184980A
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US
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Sulfuric acid catalyst and process therefor
Assignee: Stauffer Chemical Co
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Filing: 1977-12-21
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Granted: 1980-01-22
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Expires: 1997-12-21
Abstract
Abstract A sulfuric acid catalyst is made by passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid, and a potassium salt compatible with the reducing reaction in situ, until a clear blue solution is obtained, wetting diatomaceous earth with this solution, drying and then calcining to provide an active supported catalyst. The process eliminates the necessity for activating the catalyst prior to use by exposure to a gas-stream containing sulfur dioxide and sulfur trioxide.
Inventors
- 👤 Fawzy G. Sherif
- 👤 W. Novis Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:55
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/20; B01J23/22; C; C01; C01B; C01B17/00; C01B17/69; C01B17/74; C01B17/76; C01B17/78; C01B17/79
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A method of making a catalyst for the oxidation of sulfur dioxide to sulfur trioxide which comprises: passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid and a potassium salt selected from the group consisting of potassium sulfate, potassium sulfite, potassium oxalate and potassium formate in situ at a temperature between about 25° C. and about 120° C. to provide a clear blue solution; impregnating diatomaceous earth with said solution; shaping the impregnated diatomaceous earth into pellets; drying the impregnated diatomaceous earth pellets; and calcining the dried diatomaceous earth pellets, thereby providing an active catalyst.
Claim 2
Independent Claim
99 words
A method of making a catalyst for the oxidation of sulfur dioxide to sulfur trioxide which comprises: passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid and a potassium salt selected from the group consisting of potassium sulfate, potassium sulfite, potassium oxalate and potassium formate in situ at a temperature between about 25° C. and about 120° C. to provide a clear blue solution; impregnating diatomaceous earth with said solution; shaping the impregnated diatomaceous earth into pellets; drying the impregnated diatomaceous earth pellets; and calcining the dried diatomaceous earth pellets, thereby providing an active catalyst.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein a temperature between about 100° and about 120° C. is employed.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein said potassium salt is potassium sulfate.
Claim 5
Independent Claim
93 words
A method of making a catalyst for the oxidation of sulfur dioxide to sulfur trioxide which comprises: passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid and a potassium salt selected from the group consisting of potassium sulfate, potassium sulfite, potassium oxalate and potassium formate in situ at a temperature between about 25° C. and about 120° C. to provide a clear blue solution; impregnating pelletized diatomaceous earth with said solution; drying the impregnated diatomaceous earth pellets; and calcining the dried diatomaceous earth pellets, thereby providing an active catalyst.
Claim 6
Independent Claim
93 words
A method of making a catalyst for the oxidation of sulfur dioxide to sulfur trioxide which comprises: passing sulfur dioxide gas into an aqueous mixture of vanadium oxide, sulfuric acid and a potassium salt selected from the group consisting of potassium sulfate, potassium sulfite, potassium oxalate and potassium formate in situ at a temperature between about 25° C. and about 120° C. to provide a clear blue solution; impregnating pelletized diatomaceous earth with said solution; drying the impregnated diatomaceous earth pellets; and calcining the dried diatomaceous earth pellets, thereby providing an active catalyst.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein a temperature between about 100° C. and about 120° C. is employed.
Claim 8
Dependent Claim
12 words
The method of claim 4 wherein said potassium salt is potassium sulfate.
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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) | 1983-01-21 | 1983-07-23 | 1984-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-21 | 1987-07-23 | 1988-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-21 | 1991-07-23 | 1992-01-22 | $7700.00 | Window Closed / Lapsed |