US2656397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isomerization and separation of xylenes
Assignee: Shell Development Co
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Filing: 1952-03-08
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Granted: 1953-10-20
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Expires: 1972-03-08
Abstract
No abstract record available.
Inventors
- 👤 Holzman George
- 👤 George M Good
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:53
CPC Classifications
B; B01; B01J; B01J21/00; C; C07; C07C; C07C5/00; C07C5/22; C07C5/27; C07C5/2729; C07C5/2732; C07C5/2735; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
5% AND 5% OF FLUORINE AND DEVOID OF HYDROGENATION PROMOTERS IN THE PRESENCE OF HYDROGEN UNDER A PRESSURE OF FROM 50 TO 1000 P.S.I.G. AND AT A TEMPERATURE BETWEEN 350* C. AND 485* C. BELOW THAT CAUSING ANY APPRECIABLE SPLITTING OF ALKYL GROUPS, WHEREBY THE XYLENE IS SELECTIVELY ISOMERIZED TO THE EXCLUSION OF ETHYL BENZENE.
Claim 2
Dependent Claim
54 words
THE PROCESS FOR THE SELECTIVE CATALYTIC ISOMERIZATION OF XYLENES IN THE PRESENCE OF ETHVL BENZENE WHICH COMPRISES CONTACTING A XYLENE FRACTION CONTAINING AT LEAST 8% ETHYL BENZENE AND AT LEAST ONE XYLENE IN MORE THAN ITS EQUILIBRIUM CONCENTRATION AND SUBSTANTIALLY DEVOID OF ALIPHATIC HYDROCARBONS WITH A XEROGEL CATALYST CONSISTING OF ALUMINA PROMOTED WITH BETWEEN
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) | 1956-10-19 | 1957-04-20 | 1957-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-19 | 1961-04-20 | 1961-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-19 | 1965-04-20 | 1965-10-20 | $7700.00 | Window Closed / Lapsed |