US3679579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering highly pure aromatic substances from hydrocarbon mixtures containing both aromatic and non-aromatic substances
Assignee: Heinrich Koppers GmbH
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Filing: 1971-03-22
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Granted: 1972-07-25
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Expires: 1991-03-22
Abstract
Abstract PROCESS FOR RECOVERING HIGHLY PURE AROMATIC SUBSTANCES FROM HYDROCARBON MIXTURES WHICH CONTAIN IN ADDITION TO THE AROMATIC SUBSTANCES VARYING AMOUNTS OF NON-AROMATIC SUBSTANCES BY LIQUID-LIQUID EXTRACTION ADVANTAGEOUSLY IN COMBINATION WITH AN AFTER ARRANGED EXTRACTIVE DISTILLATION CHARACTERIZED IN THAT THERE IS USED AS SELECTIVE SOLVENT A MIXTURE OF N-SUBSTITUTED MORPHOLINE AND N-SUBSTITUTED SUCCINIMIDE IN A MIXING RANGE OF BETWEEN 90 WT. PERCENT N-SUBSTITUTED MORPHOLINE AND 10 WT. PERCENT N-SUBSTITUTED SUCCINIMIDE AND 30 WT. PERCENT N-SUBSTITUTED MORPHOLINE AND 70 WT.-PERCENT N-SUBSTITUTED SUCCINIMIDE.
Inventors
- 👤 Gerhard Preusser
- 👤 Martin Schulze
- 👤 Klaus Richter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:53
CPC Classifications
C; C10; C10G; C10G21/00; C10G21/06; C10G21/12; C10G21/20; B; B01; B01D; B01D11/00; B01D11/04; B01D11/0488; C07; C07C; C07C7/00; C07C7/10
Claims Analysis
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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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |