Patent US2866833A successfully refreshed from Google Patents.
US2866833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paraxylene purification system
Assignee: Standard Oil Co
•
Filing: 1953-09-14
•
Granted: 1958-12-30
•
Expires: 1973-09-14
Abstract
No abstract record available.
Inventors
- 👤 Jr Charles A Spiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:11
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0013; B01D9/0059; C; C07; C07C; C07C7/00; C07C7/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
224 words
THE METHOD OF OBTAINING 98 TO 99 PERCENT PURE XYLENE FROM A C8 HYDROCARBON CHARGE CONTAINING ABOUT 8 TO 25 PERCENT PARAXYLENE IN ADMIXTURE WITH OTHER C8 XYLENE ISOMERS, ETHYL BENZENE AND PARAFFINS, WHICH METHOD COMPRISES CHILLING SAID CHARGE TO A TEMPERATURE BELOW ABOUT -100*F. AND ABOVE THE TEMPERATURE AT WHICH A COMPONENT OTHER THAN PARAXYLENE WOULD BE SOLIDIFIED, SEPARATING FROM THE RESULTING SLURRY A FIRST SOLIDS CAKE CONTAINING ABOUT 80 PERCENT SOLIDS AND A FIRST FILTRATE, MELTING THE FIRST SOLIDS CAKE AND EFFECTING PURIFICATION THEREOF IN TWO ADDITIONAL STAGES OF CRYSTALLIZATION AND SEPARATION WHEREIN A SECOND SOLIDS CAKE, CONTAINING ABOUT 90 TO 95 PERCENT SOLIDS IS OBTAINED BY CRYSTALLIZING AT A TEMPERATURE IN THE RANGE OF ABOUT +20* TO -30*F. AND BY SEPARATING A SECOND FILTRATE THEREFROM IN THE FIRST OF SAID ADDITIONAL STAGES AND WHEREIN A THIRD SOLIDS CAKE IS OBTAINED BY CRYSTALLIZING AT A TEMPERATURE IN THE RANGE OF ABOUT 30* TO 35*F. AND BY SEPARATING A THIRD FILTRATE THEREFROM IN THE SECOND OF SAID ADDITIONAL STAGES, RETURNING AT LEAST A PART OF THE FILTRATE FROM THE SECOND OF THE ADDITIONAL STAGES TO THE FIRST OF THE ADDITIONAL STAGES, RETURNING AT LEAST A MINOR PART OF THE FILTRATE FROM STEP AND MELTING THE CAKE FROM THE SECOND OF THE ADDITIONAL STAGES TO OBTAIN A PARAXYLENE OF 98 TO 99 PERCENT PURITY.
Claim 2
Independent Claim
224 words
THE METHOD OF OBTAINING 98 TO 99 PERCENT PURE XYLENE FROM A C8 HYDROCARBON CHARGE CONTAINING ABOUT 8 TO 25 PERCENT PARAXYLENE IN ADMIXTURE WITH OTHER C8 XYLENE ISOMERS, ETHYL BENZENE AND PARAFFINS, WHICH METHOD COMPRISES CHILLING SAID CHARGE TO A TEMPERATURE BELOW ABOUT -100*F. AND ABOVE THE TEMPERATURE AT WHICH A COMPONENT OTHER THAN PARAXYLENE WOULD BE SOLIDIFIED, SEPARATING FROM THE RESULTING SLURRY A FIRST SOLIDS CAKE CONTAINING ABOUT 80 PERCENT SOLIDS AND A FIRST FILTRATE, MELTING THE FIRST SOLIDS CAKE AND EFFECTING PURIFICATION THEREOF IN TWO ADDITIONAL STAGES OF CRYSTALLIZATION AND SEPARATION WHEREIN A SECOND SOLIDS CAKE, CONTAINING ABOUT 90 TO 95 PERCENT SOLIDS IS OBTAINED BY CRYSTALLIZING AT A TEMPERATURE IN THE RANGE OF ABOUT +20* TO -30*F. AND BY SEPARATING A SECOND FILTRATE THEREFROM IN THE FIRST OF SAID ADDITIONAL STAGES AND WHEREIN A THIRD SOLIDS CAKE IS OBTAINED BY CRYSTALLIZING AT A TEMPERATURE IN THE RANGE OF ABOUT 30* TO 35*F. AND BY SEPARATING A THIRD FILTRATE THEREFROM IN THE SECOND OF SAID ADDITIONAL STAGES, RETURNING AT LEAST A PART OF THE FILTRATE FROM THE SECOND OF THE ADDITIONAL STAGES TO THE FIRST OF THE ADDITIONAL STAGES, RETURNING AT LEAST A MINOR PART OF THE FILTRATE FROM STEP AND MELTING THE CAKE FROM THE SECOND OF THE ADDITIONAL STAGES TO OBTAIN A PARAXYLENE OF 98 TO 99 PERCENT PURITY.
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) | 1961-12-29 | 1962-06-30 | 1962-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-29 | 1966-06-30 | 1966-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-29 | 1970-06-30 | 1970-12-30 | $7700.00 | Window Closed / Lapsed |