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US4929358A
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Polyurethane-imide membranes and their use for the separation of aromatics from non-aromatics
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1989-08-09
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Granted: 1990-05-29
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Expires: 2009-08-09
Abstract
Abstract Aromatics are separated from non-aromatics by permeation of the aromatic through a polyurethane-imide membrane. Permeation is conducted under pervaporation, perstraction, reverse osmosis, or dialysis conditions. The membrane is a polyurethane-imide membrane made using polyurethane-imide copolymers which are made by end capping a polyol with a polyisocyanate and then chain extending by reaction with an anhydride.
Inventors
- 👤 Bernd A. Koenitzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:27
CPC Classifications
C; C10; C10G; C10G31/00; C10G31/11; B; B01; B01D; B01D71/00; B01D71/06; B01D71/76; C07; C07C; C07C7/00; C07C7/144; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; B01D71/54
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
45 words
A method for separating aromatic hydrocarbons from a mixture containing said aromatic hydrocarbons in combination with non-aromatic hydrocarbons, the method comprising contacting said mixture under appropriate separation conditions with a membrane comprising a polyurethane-imide membrane to thereby selectively permeate the aromatic hydrocarbon through the membrane.
Claim 2
Independent Claim
45 words
A method for separating aromatic hydrocarbons from a mixture containing said aromatic hydrocarbons in combination with non-aromatic hydrocarbons, the method comprising contacting said mixture under appropriate separation conditions with a membrane comprising a polyurethane-imide membrane to thereby selectively permeate the aromatic hydrocarbon through the membrane.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the separation is conducted under reverse osmosis, dialysis, pervaporation or perstraction conditions.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the separation is conducted under pervaporation or perstraction conditions.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein the separation is conducted under pervaporation conditions.
Claim 6
Dependent Claim
16 words
The method of claim 1 or 4 wherein the polyurethane-imide membrane is supported on a backing.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein the backing is teflon or polypropylene.
Claim 8
Dependent Claim
10 words
The method of claim 6 wherein the backing is teflon.
Claim 9
Dependent Claim
61 words
The method of claim 1 wherein the mixture containing aromatics and non-aromatics which is contacted with the polyurethane-imide membrane is selected from cat naphtha, heavy cat naphtha, light aromatics content streams boiling in the C 5 -300° F. range, light catalytic cycle oil boiling in the 400°-650° F. range, reformate streams, and streams containing recoverable quantities of benzene, toluene and xylene.
Claim 10
Dependent Claim
39 words
The method of claim 4 wherein the pervaporation process is performed at a temperature up to about 200° C. and at a vacuum on the order of 1 to 50 mm Hg on the permeate side of the membrane.
Claim 11
Dependent Claim
39 words
The method of claim 7 wherein the pervaporation process is performed at a temperature up to about 200° C. and at a vacuum on the order of 1 to 50 mm Hg on the permeate side of the membrane.
References Cited (Backward Citations)
US4474858A
Cited
US4802987A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |