Patent US5466345A successfully refreshed from Google Patents.
US5466345A
Expired / Lapsed
US
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Separation of o-xylene from p-xylene and m-xylene by azeotropic distillation
Assignee: Individual
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Filing: 1995-05-31
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Granted: 1995-11-14
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Expires: 2015-05-31
Abstract
Abstract o-Xylene cannot be separated from p-xylene and m-xylene by conventional distillation or rectification because of the proximity of their boiling points. o-Xylene can be readily separated from mixtures of p-xylene and m-xylene by azeotropic distillation. Effective agents are 3-methyl-1-butanol, methyl propionate and 3-pentanone.
Inventors
- 👤 Lloyd Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:25
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/04; C07C7/05; C07C7/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A method for recovering o-xylene from a mixture of o-xylene, p-xylene and m-xylene which comprises distilling a mixture of o-xylene, p-xylene and m-xylene in the presence of an azeotrope forming agent, recovering the p-xylene, the m-xylene and the azeotrope forming agent as overhead product and obtaining the o-xylene as bottoms product, wherein said azeotrope forming agent consists of one material selected from the group consisting of methanol, ethanol, isopropanol, cyclopentanol, 1-butanol, n-amyl alcohol, 3-methyl-1-butanol, methyl acetate, methyl trimethyl acetate, propyl formate, methyl propionate, methyl pivalate, butyl formate, methyl lactate, n-pentyl propionate, butyl benzoate, methyl butyrate, isobutyl acetate, acetal, dimethyl carbonate, diethyl carbonate, propyl propionate, 2,3-butanedione, chloroform, methylene chloride, trichloroethylene, 1,1,2-trichloroethane, tetrahydrofuran, t-butyl methyl ether, t-amyl methyl ether, isopropyl ether, butyraldehyde oxime, benzyl cyanide, 2-butanone, 3-pentanone, 1,1,1-trichloroethane, butyraldehyde and 1-methyl piperazine.
Claim 2
Independent Claim
130 words
A method for recovering o-xylene from a mixture of o-xylene, p-xylene and m-xylene which comprises distilling a mixture of o-xylene, p-xylene and m-xylene in the presence of an azeotrope forming agent, recovering the p-xylene, the m-xylene and the azeotrope forming agent as overhead product and obtaining the o-xylene as bottoms product, wherein said azeotrope forming agent consists of one material selected from the group consisting of methanol, ethanol, isopropanol, cyclopentanol, 1-butanol, n-amyl alcohol, 3-methyl-1-butanol, methyl acetate, methyl trimethyl acetate, propyl formate, methyl propionate, methyl pivalate, butyl formate, methyl lactate, n-pentyl propionate, butyl benzoate, methyl butyrate, isobutyl acetate, acetal, dimethyl carbonate, diethyl carbonate, propyl propionate, 2,3-butanedione, chloroform, methylene chloride, trichloroethylene, 1,1,2-trichloroethane, tetrahydrofuran, t-butyl methyl ether, t-amyl methyl ether, isopropyl ether, butyraldehyde oxime, benzyl cyanide, 2-butanone, 3-pentanone, 1,1,1-trichloroethane, butyraldehyde and 1-methyl piperazine.
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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) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |