Patent US2649456A successfully refreshed from Google Patents.
Patent US3657374A successfully refreshed from Google Patents.
US3657374A
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US
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Recovery of isobutylene from mixtures containing the same and butadiene
Assignee: BASF SE
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Filing: 1970-02-26
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Granted: 1972-04-18
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Expires: 1990-02-26
Abstract
Abstract RECOVERY OF ISOBUTYLENE FROM MIXTURES OF C4-HYDROCARBONS BY ABSORPTION IN A MIXTURE OF TERT-BUTANOL, SULFURIC ACID AND WATER, RECOVERY OF TERT-BUTANOL BY HEATING THE AQUEOUS SOLUTION OF TERT-BUTANOL IN SULFURIC ACID AS AN AZEOTROPE WITH 12% WATER, FRACTIONATION OF THE SAID AZEOTROPE AND DECOMPOSITION OF THE TERT-BUTANOL BY PASSING IT OVER ALUMINA AT ABOUT 300*C.
Inventors
- 👤 Karl Schloemer
- 👤 Otto Nagel
- 👤 Rolf Platz
- 👤 Hans Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:33
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/14858; C07C7/14866; C07C7/17; C07C7/171; Y; Y10; Y10S; Y10S585/00; Y10S585/929; Y10S585/93; Y10S585/934
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |