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US4746333A
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Method for producing an integral asymmetric gas separating membrane and the resultant membrane
Assignee: GKSS Forshungszentrum Geesthacht GmbH
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Filing: 1986-07-15
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Granted: 1988-05-24
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Expires: 2006-07-15
Abstract
Abstract A method of manufacturing an integral asymmetric membrane for separating gases from each other, wherewith a membrane-former, a solvent, and/or an agent which is not a solvent for the membrane-former are mixed, are spread out or otherwise extended over a greater area, and are contacted with a precipitation agent. The integral asymmetric membrane for gas separation is particularly suitable for CO2/CH4 separation, has improved insensitivity to water and relatively high strength and durability, and has high separation throughput and selectivity (permeability of >/==0.1 cu m/sq m/hr/bar for CO2, and CO2/CH4 selectivity of about 30-40), which high separation throughput and selectivity are necessary for economical separation of materials. The integral asymmetric membrane is made from a polymer, particularly polyether sulfone, as a membrane-former, is mixed with a halogenated hydrocarbon, as a solvent, as well as with a non-solvent in the form of an aliphatic alcohol, which non-solvent may possibly comprise, in addition to the aliphatic alcohol, an aliphatic carboxylic acid or an alkylbenzene.
Inventors
- 👤 Klaus V. Peinemann
- 👤 Ingo Pinnau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:46
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/66; B01D71/68; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D69/00; B01D69/02; B01D69/08; B01D2323/00; B01D2323/12; B01D2325/00; B01D2325/02; B01D2325/022
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
52 words
An integral asymmetric membrane for separating gases, manufactured by mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore-forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, and contacting said film with an organic precipitation agent to form a membrane.
Claim 2
Dependent Claim
52 words
An integral asymmetric membrane for separating gases, manufactured by mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore-forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, and contacting said film with an organic precipitation agent to form a membrane.
Claim 3
Dependent Claim
13 words
The membrane set forth in claim 1, wherein said membrane-former is polyether sulfone.
Claim 4
Dependent Claim
13 words
The membrane set forth in claim 1, wherein said precipitation agent is methanol.
Claim 5
Independent Claim
61 words
A method of manufacturing an integral asymmetric membrane for separating gases from each other, comprising steps for: mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, and contacting said film with an organic precipitation agent to form a membrane.
Claim 6
Independent Claim
61 words
A method of manufacturing an integral asymmetric membrane for separating gases from each other, comprising steps for: mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, and contacting said film with an organic precipitation agent to form a membrane.
Claim 7
Dependent Claim
13 words
The method set forth in claim 4, wherein said membrane-former is polyether sulfone.
Claim 8
Dependent Claim
18 words
The method set forth in claim 5 including drying said membrane in air or in an inert gas.
Claim 9
Dependent Claim
14 words
The method set forth in claim 5 including coating said membrane with an elastomer.
Claim 10
Dependent Claim
23 words
The method set forth in claim 5, wherein said solvent is selected from the group consisting of dichloromethane, 1,1,2-trichloroethane, chloroform, and mixtures thereof.
Claim 11
Dependent Claim
13 words
The method set forth in claim 5, wherein said precipitation agent is methanol.
Claim 12
Dependent Claim
19 words
The method set forth in claim 5, wherein said solvent is a halogenated hydrocarbon of one to three carbons.
Claim 13
Dependent Claim
27 words
The method set forth in claim 10, wherein said agent which is not a solvent for said membrane-former contains an aliphatic alcohol of two to eight carbons.
Claim 14
Dependent Claim
36 words
The method set forth in claim 11, wherein said agent which is not a solvent for said membrane-former contains an aliphatic carboxylic acid of one to four carbons or an alkylbenzene of seven to ten carbons.
Claim 15
Dependent Claim
31 words
The method set forth in claim 11, wherein said agent which is not a solvent for said membrane-former is selected from the group consisting of 1-propanol, 2-propanol, 1-butanol, 2-butanol, and cyclohexanol.
Claim 16
Dependent Claim
32 words
The method set forth in claim 12, wherein said agent which is not a solvent for said membrane-former is selected from the group consisting of formic acid, acetic acid, toluene, and xylene.
Claim 17
Dependent Claim
32 words
The method set forth in claim 13, wherein said agent which is not a solvent for said membrane-former comprises between about 3 wt. % and about 25 wt. % of said mixture.
Claim 18
Dependent Claim
32 words
The method set forth in claim 14, wherein said agent which is not a solvent for said membrane-former comprises between about 3 wt. % and about 25 wt. % of said mixture.
Claim 19
Independent Claim
78 words
A method of manufacturing an integral asymmetric membrane for separating gases from each other, comprising steps for: mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore-forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, contacting said film with an organic precipitation agent comprising methanol and an additive selected from the group consisting of ethylcellulose, cellulose acetate/propionate, cellulose acetate/butyrate, and mixtures thereof to form a membrane.
Claim 20
Independent Claim
78 words
A method of manufacturing an integral asymmetric membrane for separating gases from each other, comprising steps for: mixing a membrane-former, a halogenated hydrocarbon solvent, and a pore-forming agent which is not a solvent for said membrane-former to form a mixture, casting said mixture to form a film, contacting said film with an organic precipitation agent comprising methanol and an additive selected from the group consisting of ethylcellulose, cellulose acetate/propionate, cellulose acetate/butyrate, and mixtures thereof to form a membrane.
Claim 21
Dependent Claim
13 words
The method set forth in claim 17, wherein said membrane-former is polyether sulfone.
Claim 22
Dependent Claim
18 words
The method set forth in claim 17, including drying said membrane in air or in an inert gas.
Claim 23
Dependent Claim
14 words
The method set forth in claim 17, including coating said membrane with an elastomer.
References Cited (Backward Citations)
US4026977A
Cited
US4673418A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |