US2824147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of xylenes
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1955-03-08
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Granted: 1958-02-18
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Expires: 1975-03-08
Abstract
No abstract record available.
Inventors
- 👤 Coats Robert Reid
- 👤 Williams Gilbert Arthur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:13
CPC Classifications
C; C07; C07C; C07C15/00; C07C15/02; C07C15/067; C07C15/08; B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0013; C07C7/00; C07C7/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
A CONTINUOUS PROCESS FOR THE PRODUCTION OF PARAXYLENE SUBSTANTIALLY FREE FROM ETHYLENE BENZENE, AND SIMULTANEOUSLY AN ETHYL BENZENE CONCENTRATE, FROM XYLENE FEEDSTOCK CONTAINING PARA-XYLENE AND ETHYL BENZENE, AND WHEREIN THE SEPARATION OF SAID MATERIALS IS EFFECTED SOLELY BY A CRYSTALLIZATION TECHNIQUE, WHICH COMPRISES SUBJECTING THE FEEDSTOCK TO A TEMPERATURE WITHIN THE RANGE OF FROM -60*C. TO -75*C. WHEREBY CRYSTALS OF PARAXYLENE ARE PRECIPITATED, SEPARATING THESE CRYSTALS BY CENTRIFUGING WHEREBY THERE IS OBTAINED PARA-XYLENE OF NOT LESS THAN 95% PURITY, SUBJECTING THE RESULTING MOTHER LIQUOR TO A TEMPERATURE BELOW -75*C. AND NOT BELOW -110*C., WHEREBY MIXED XYLENE CRYSTALS RICH IN METAAND ORTHO-XYLENES ARE PRECIPITATED, CENTRIFUGING THE MIXTURE WHEREBY THERE ARE OBTAINED AN ETHYL BENZENE CON-
Claim 2
Dependent Claim
114 words
A CONTINUOUS PROCESS FOR THE PRODUCTION OF PARAXYLENE SUBSTANTIALLY FREE FROM ETHYLENE BENZENE, AND SIMULTANEOUSLY AN ETHYL BENZENE CONCENTRATE, FROM XYLENE FEEDSTOCK CONTAINING PARA-XYLENE AND ETHYL BENZENE, AND WHEREIN THE SEPARATION OF SAID MATERIALS IS EFFECTED SOLELY BY A CRYSTALLIZATION TECHNIQUE, WHICH COMPRISES SUBJECTING THE FEEDSTOCK TO A TEMPERATURE WITHIN THE RANGE OF FROM -60*C. TO -75*C. WHEREBY CRYSTALS OF PARAXYLENE ARE PRECIPITATED, SEPARATING THESE CRYSTALS BY CENTRIFUGING WHEREBY THERE IS OBTAINED PARA-XYLENE OF NOT LESS THAN 95% PURITY, SUBJECTING THE RESULTING MOTHER LIQUOR TO A TEMPERATURE BELOW -75*C. AND NOT BELOW -110*C., WHEREBY MIXED XYLENE CRYSTALS RICH IN METAAND ORTHO-XYLENES ARE PRECIPITATED, CENTRIFUGING THE MIXTURE WHEREBY THERE ARE OBTAINED AN ETHYL BENZENE CON-
References Cited (Backward Citations)
US1940611A
Cited
FR833153A
Cited
US2540977A
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US2532276A
Cited
US2541682A
Cited
US2622115A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-02-17 | 1961-08-19 | 1962-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-17 | 1965-08-19 | 1966-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-17 | 1969-08-19 | 1970-02-18 | $7700.00 | Window Closed / Lapsed |