Patent US2651665A successfully refreshed from Google Patents.
US2651665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of pure paraxylene
Assignee: Standard Oil Development Co
•
Filing: 1950-06-10
•
Granted: 1953-09-08
•
Expires: 1970-06-10
Abstract
No abstract record available.
Inventors
- 👤 John D Booker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:07
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0059; C; C07; C07C; C07C7/00; C07C7/14; Y; Y10; Y10S; Y10S208/00; Y10S208/95
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
195 words
A PROCESS FOR SEPARATING PARAXYLENE OF OVER 90% PURITY FROM A MIXTURE OF IT WITH AT LEAST ONE OTHER ISOMERIC XYLENE WHEREIN THE MIXTURE CONTAINS A MINOR PORTION OF PARAXYLENE WHICH COMPRISES COOLING SAID MIXTURE TO A TEMPERATURE NO LOWER THAN ITS EUTECTIC POINT TO FORM A FIRST SLURRY OF PARAXYLENE CRYSTALS IN A MOTHER LIQUOR, CENTRIFUGING SAID FIRST SLURRY FOR NO MORE THAN TWO MINUTES AND SUFFICIENT TO SEPARATE A FIRST CAKE COMPRISING A MAJOR PORTION OF PARAXYLENE AND A FIRST MOTHER LIQUOR, HEATING THE FIRST CAKE TO A TEMPERATURE IN THE RANGE BETWEEN -30* AND 40* F. TO FORM A SECOND SLURRY CONTAINING PARAXYLENE CRYSTALS IN AN AMOUNT IN THE RANGE BETWEEN 30% AND 85% BY WEIGHT OF SAID SLURRY, CENTRIFUGING THE SECOND SLURRY FOR A TIME SUFFICIENT TO SEPARATE A SECOND CAKE HAVING A PARAXYLENE CONTENT IN EXCESS OF 90% AND A SECOND MOTHER LIQUOR THE TIME OF CENTRIFUGING THE SECOND SLURRY PLUS THE TIME FOR CENTRIFUGING THE FIRST SLURRY BEING NO GREATER THAN A TOTAL OF TEN MINUTES, ADMIXING AT LEAST A PORTION OF THE SECOND MOTHER LIQUOR WITH THE FEED MIXTURE, AND RECOVERING SUBSTANTIALLY PURE PARAXYLENE FROM SAID SECOND CAKE.
Claim 2
Dependent Claim
195 words
A PROCESS FOR SEPARATING PARAXYLENE OF OVER 90% PURITY FROM A MIXTURE OF IT WITH AT LEAST ONE OTHER ISOMERIC XYLENE WHEREIN THE MIXTURE CONTAINS A MINOR PORTION OF PARAXYLENE WHICH COMPRISES COOLING SAID MIXTURE TO A TEMPERATURE NO LOWER THAN ITS EUTECTIC POINT TO FORM A FIRST SLURRY OF PARAXYLENE CRYSTALS IN A MOTHER LIQUOR, CENTRIFUGING SAID FIRST SLURRY FOR NO MORE THAN TWO MINUTES AND SUFFICIENT TO SEPARATE A FIRST CAKE COMPRISING A MAJOR PORTION OF PARAXYLENE AND A FIRST MOTHER LIQUOR, HEATING THE FIRST CAKE TO A TEMPERATURE IN THE RANGE BETWEEN -30* AND 40* F. TO FORM A SECOND SLURRY CONTAINING PARAXYLENE CRYSTALS IN AN AMOUNT IN THE RANGE BETWEEN 30% AND 85% BY WEIGHT OF SAID SLURRY, CENTRIFUGING THE SECOND SLURRY FOR A TIME SUFFICIENT TO SEPARATE A SECOND CAKE HAVING A PARAXYLENE CONTENT IN EXCESS OF 90% AND A SECOND MOTHER LIQUOR THE TIME OF CENTRIFUGING THE SECOND SLURRY PLUS THE TIME FOR CENTRIFUGING THE FIRST SLURRY BEING NO GREATER THAN A TOTAL OF TEN MINUTES, ADMIXING AT LEAST A PORTION OF THE SECOND MOTHER LIQUOR WITH THE FEED MIXTURE, AND RECOVERING SUBSTANTIALLY PURE PARAXYLENE FROM SAID SECOND CAKE.
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) | 1956-09-07 | 1957-03-09 | 1957-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-09-07 | 1961-03-09 | 1961-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-09-07 | 1965-03-09 | 1965-09-08 | $7700.00 | Window Closed / Lapsed |