US3793386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of xylenes by adsorption on partially dehydrated copper zeolites
Assignee: Sun Research and Development Co
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Filing: 1972-06-06
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Granted: 1974-02-19
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Expires: 1992-06-06
Abstract
Abstract SELECTIVE ADSORPTION OF P-XYLENE FROM A FLUID MIXTURE CONTAINING M-XYLENE CAB BE OBTAINED WITH COPPER-EXCHANGED MOLECULAR SIEVES (CRYSTALLINE ALUMINO-SILICATE ZEOLITES) WHICH HAVE A WATER LOSS ON IGNITION AT 800* C. IN THE RANGE OF 8-20 WT. PERCENT AND PREFERABLY, HAVE BEEN PARTIALLY DEHYDRATED AT A TEMPERATURE IN THE RANGE OF 50-300* C. PREFERABLY THE AL/SI RATIO IN THE ZEOLITE FRAMEWORK IS IN THE RANGE OF 0.2-0.65. FOR EXAMPLE, P-XYLENE CAN BE SEPARATED FROM M-XYLENE BY SELECTIVE ADSORPTION AT 100* C. OF THE P-XYLENE ON CUY ZEOLITE WHICH WAS PARTIALLY DEHYDRATED AT 82* C. AND CONTAINED ABOUT 15 WT. PERCENT WATER BY IGNITION ANALYSIS.
Inventors
- 👤 R Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:54
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/12; C07C7/13
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |