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US4478948A
Expired / Lapsed
US
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Process for improving the activity of used supported silver catalysts
Assignee: Hoechst AG
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Filing: 1983-08-04
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Granted: 1984-10-23
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Expires: 2003-08-04
Abstract
Abstract A method for improving the activity of a used supported silver catalyst, used for the manufacture of ethylene oxide by reaction of ethylene with oxygen or air, which method consists essentially of: (a) impregnating said used catalyst at a temperature from 80° C. to 150° C. and for 0.75 hour to 10 hours with an impregnating solution containing water, a water-miscible organic solvent selected from the group consisting of methanol, ethanol, propanol, and isopropanol, at least one compound of cesium, rubidium, or of cesium and rubidium in an amount providing from 50 mg to 1000 mg per kilogram of solution, said solution containing from 5 to 50 percent by weight of water; (b) separating the impregnated catalyst from excess impregnating solution; and (c) drying the impregnated catalyst.
Inventors
- 👤 Siegfried Rebsdat
- 👤 Sigmund Mayer
- 👤 Josef Alfranseder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:20
CPC Classifications
C; C07; C07D; C07D301/00; C07D301/02; C07D301/03; C07D301/04; C07D301/08; C07D301/10; B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/66; B01J23/90; B01J23/96; B01J38/00; B01J38/48; B01J38/485; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
127 words
A method for improving the activity of a used supported silver catalyst, used for the manufacture of ethylene oxide by reaction of ethylene with oxygen or air, which method consists essentially of: (a) impregnating said used catalyst at a temperature from 80° C. to 150°0 C. and for 0.75 hour to 10 hours with an impregnating solution containing water, a water-miscible organic solvent selected from the group consisting of methanol, ethanol, propanol, and isopropanol, at least one compound of cesium, rubidium, or of cesium and rubidium in an amount providing from 50 mg to 1000 mg per kilogram of solution, said solution containing from 5 to 50 percent by weight of water; (b) separating the impregnated catalyst from excess impregnating solution; and (c) drying the impregnated catalyst.
Claim 2
Independent Claim
127 words
A method for improving the activity of a used supported silver catalyst, used for the manufacture of ethylene oxide by reaction of ethylene with oxygen or air, which method consists essentially of: (a) impregnating said used catalyst at a temperature from 80° C. to 150°0 C. and for 0.75 hour to 10 hours with an impregnating solution containing water, a water-miscible organic solvent selected from the group consisting of methanol, ethanol, propanol, and isopropanol, at least one compound of cesium, rubidium, or of cesium and rubidium in an amount providing from 50 mg to 1000 mg per kilogram of solution, said solution containing from 5 to 50 percent by weight of water; (b) separating the impregnated catalyst from excess impregnating solution; and (c) drying the impregnated catalyst.
Claim 3
Dependent Claim
21 words
A method as in claim 1 wherein said used catalyst is impregnated at a temperature from 90°0 C. to 130° C.
Claim 4
Dependent Claim
18 words
A method as in claim 1 wherein said used catalyst is impregnated for 1 hour to 3 hours.
Claim 5
Dependent Claim
20 words
A method as in claim 1 wherein said impregnating solution contains from 10 to 40 percent by weight of water.
Claim 6
Dependent Claim
20 words
A method as in claim 4 wherein said impregnating solution contains from 10 to 30 percent by weight of water.
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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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |