US2769852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of xylene isomers by fractional crystallization
Assignee: California Research LLC
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Filing: 1953-04-01
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Granted: 1956-11-06
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Expires: 1973-04-01
Abstract
No abstract record available.
Inventors
- 👤 Marvin H Paulson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:29
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0009; B01D9/0059; C; C07; C07C; C07C7/00; C07C7/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
IN A PROCESS FOR RECOVERING XYLENES FROM HYDROCARBON LIQUIDS CONTAINING XYLENES BY FRACTIONAL CRYSTALLIZATION, THE IMPROVED METHOD WHICH COMPRISES COOLING A MIXTURE OF METHANOL AND WATER, CONTAINING 2 TO 6 PARTS OF WATER TO 10 PARTS OF METHANOL TO A TEMPERATURE BELOW -100* F. BY INDIRECT HEAT EXCHANGE IN A COOLING ZONE, DIRECTLY CONTACTING SUFFICIENT COOLED METHANOL-WATER MIXTURE WITH SAID HYDROCARBON LIQUID IN A CRYSTALLIZATION ZONE TO CAUSE FORMATION OF SOLID XYLENE CRYSTALS, SEPARATING A SOLID XYLENE PHASE FROM A MOTHER LIQUOR PHASE, SETTLING THE MOTHER LIQUOR PHASE TO SEPARATE A HYDROCARBON PHASE AND A METHANOL-WATER PHASE, AND RETURNING THE METHANOL-WATER PHASE TO THE COOLING ZONE.
Claim 2
Dependent Claim
106 words
IN A PROCESS FOR RECOVERING XYLENES FROM HYDROCARBON LIQUIDS CONTAINING XYLENES BY FRACTIONAL CRYSTALLIZATION, THE IMPROVED METHOD WHICH COMPRISES COOLING A MIXTURE OF METHANOL AND WATER, CONTAINING 2 TO 6 PARTS OF WATER TO 10 PARTS OF METHANOL TO A TEMPERATURE BELOW -100* F. BY INDIRECT HEAT EXCHANGE IN A COOLING ZONE, DIRECTLY CONTACTING SUFFICIENT COOLED METHANOL-WATER MIXTURE WITH SAID HYDROCARBON LIQUID IN A CRYSTALLIZATION ZONE TO CAUSE FORMATION OF SOLID XYLENE CRYSTALS, SEPARATING A SOLID XYLENE PHASE FROM A MOTHER LIQUOR PHASE, SETTLING THE MOTHER LIQUOR PHASE TO SEPARATE A HYDROCARBON PHASE AND A METHANOL-WATER PHASE, AND RETURNING THE METHANOL-WATER PHASE TO THE COOLING ZONE.
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) | 1959-11-06 | 1960-05-07 | 1960-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-11-06 | 1964-05-07 | 1964-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-11-06 | 1968-05-07 | 1968-11-06 | $7700.00 | Window Closed / Lapsed |