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US5397441A
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Separation of ethyl benzene from o-xylene by extractive distillation
Assignee: Individual
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Filing: 1994-01-14
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Granted: 1995-03-14
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Expires: 2014-01-14
Abstract
Abstract Ethyl benzene is difficult to separate from o-xylene by conventional distillation or rectification because of the closeness of their boiling points. Ethyl benzene can be readily separated from o-xylene by extractive distillation. Effective agents are phenol, cresols, nitrotoluenes and cyclododecanol.
Inventors
- 👤 Lloyd Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:43
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/04; C07C7/05; C07C7/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
82 words
A method for recovering ethyl benzene from a mixture of ethyl benzene and o-xylene which comprises distilling a mixture of ethyl benzene and o-xylene in the presence of about one part of an extractive agent per part of ethyl benzene--o-xylene mixture, recovering the ethyl benzene as overhead product and obtaining the o-xylene and the extractive agent from the stillpot, wherein said extractive agent consists of one material selected from the group consisting of nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, cyclododecanol, 1-dodecanol and tridecyl alcohol.
Claim 2
Independent Claim
82 words
A method for recovering ethyl benzene from a mixture of ethyl benzene and o-xylene which comprises distilling a mixture of ethyl benzene and o-xylene in the presence of about one part of an extractive agent per part of ethyl benzene--o-xylene mixture, recovering the ethyl benzene as overhead product and obtaining the o-xylene and the extractive agent from the stillpot, wherein said extractive agent consists of one material selected from the group consisting of nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, cyclododecanol, 1-dodecanol and tridecyl alcohol.
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) | 1998-03-13 | 1998-09-12 | 1999-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-13 | 2002-09-12 | 2003-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-13 | 2006-09-12 | 2007-03-14 | $7700.00 | Window Closed / Lapsed |