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US4755299A
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Multi-layer membrane and the use thereof for the separation of liquid mixtures according to the pervaporation process
Assignee: GFT GESELLSCHAFT fur TRENNTECHNIK MBH A CORP OF FEDERAL REPUBLIC OF GERMANY
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Filing: 1985-09-23
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Granted: 1988-07-05
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Expires: 2005-09-23
Abstract
Abstract A multi-layer membrane having a porous backing layer of polyacrylonitrile, polysulfone or the like, and an active separating layer of polyvinyl alcohol or cellulose acetate. The membrane is particularly suitable for the separation of water-alcohol mixtures according to the pervaporation process.
Inventors
- 👤 Hartmut Bruschke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:24
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/36; B01D61/362; B01D69/00; B01D69/12; B01D69/1216; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D71/38; B01D71/381; B01D71/383
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
A process for separating a liquid mixture into separable components comprising said mixture, comprising the steps of: (a) delivering said liquid mixture to a first free surface of a composite membrane consisting essentially of (1) a non-porous layer useful for separating an aqueous liquid mixture comprising at least one organic liquid, said non-porous layer being comprised of a first polymer, and (2) at least one porous backing layer comprised of a second polymer, wherein said first polymer is cross-linked polyvinyl alcohol; and (b) applying a vaccum to, or an inert gas stream over, a second free surface of said composite membrane, such that said components of said liquid mixture are separated across said composite membrane by pervaporation.
Claim 2
Dependent Claim
117 words
A process for separating a liquid mixture into separable components comprising said mixture, comprising the steps of: (a) delivering said liquid mixture to a first free surface of a composite membrane consisting essentially of (1) a non-porous layer useful for separating an aqueous liquid mixture comprising at least one organic liquid, said non-porous layer being comprised of a first polymer, and (2) at least one porous backing layer comprised of a second polymer, wherein said first polymer is cross-linked polyvinyl alcohol; and (b) applying a vaccum to, or an inert gas stream over, a second free surface of said composite membrane, such that said components of said liquid mixture are separated across said composite membrane by pervaporation.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein said composite membrane accommodates a permeate flow of at least 1.5 kg/h.m 2 for said mixture.
Claim 4
Dependent Claim
38 words
A process according to claim 1, wherein said non-porous layer has a selectivity value B of at least 30 for a mixture comprising 80 wt% ethanol and 20 wt% water, relative to the total weight of said mixture.
Claim 5
Dependent Claim
13 words
A process according to claim 1, wherein said second polymer is a polyacrylonitrile.
Claim 6
Dependent Claim
13 words
A process according to claim 1, wherein said second polymer is a polysulfone.
Claim 7
Dependent Claim
26 words
A process according to claim 1, wherein said membrane comprises two porous layers, at least one of said backing layers being comprised of saponified cellulose triacetate.
Claim 8
Dependent Claim
19 words
A process according to claim 1, wherein said non-porous layer has a thickness of between 0.1 and 5 μm.
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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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |