Patent US3658928A successfully refreshed from Google Patents.
US3658928A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dehydration of alpha-methylbenzyl alcohol
Assignee: Shell USA Inc
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Filing: 1970-09-21
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Granted: 1972-04-25
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Expires: 1990-09-21
Abstract
Abstract STYRENE IS PREPARED BY CATALYTICALLY DEHYDRATING AMETHYLBENZYL ALCOHOL IN THE VAPOR PHASE, AT A TEMPERATURE ABOVE ABOUT 2560*C., IN THE PRESENCE OF CONTROLLED AMOUNTS OF ADDED STEAM. IN ONE EMBODIMENT, THE DEHYDRATION IS EFFECTED IN A VERTICALLY-ORIENTED CATALYSTCONTAINING REACTION ZONE, THROUGH WHICH THE SUBSTRATE ALCOHOL PASSES UPWARDLY. EVERY 75 TO 500 HOURS, THE CATALYST IS REACTIVATED BY PASSING AN AROMATIC HYDROCARBON THROUGH THE REACTOR ZONE.
Inventors
- 👤 John R Skinner
- 👤 Charles E Sanborn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:29
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/90; B01J21/00; B01J21/20; C; C07; C07C; C07C1/00; C07C1/20; C07C1/24; C07C2521/00; C07C2521/02; C07C2521/04; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |