EP0242147A2
Expired / Lapsed
EP
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The use of polycarbonate containing semipermeable membranes in the separation of gases.
Assignee: Dow Chemical Co
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Filing: 1987-04-10
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Granted: —
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Expires: 2007-04-10
Abstract
Abstract An improved gas separation membrane comprises a thin discriminating layer consisting predominantly of a carbonate polymer derived from a bisphenol corresponding to formula I wherein R at each occurrence is independently H, CI, Br, or C 1 -C 4 alkyl and R 1 is -CO-, -S-, -SO 2 -, -0-, a C 1 -C 6 divalent hydrocarbon radical, or a C 1 -C 6 divalent fluorocarbon radical, or inertly substituted C 1 -C 6 divalent hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups which are exclusively Br or CI, said gas separation membrane exhibiting a separation factor for oxygen and nitrogen at the ambient temperature of at least 6.1. The membrane has particular application to separating oxygen from nitrogen, or a nitrogen-containing gas. •
Inventors
- 👤 Joginder N. Anada
- 👤 Darrell C. Feay
- 👤 Stephen E. Bales
- 👤 Thomas O. Jeanes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 08:41
CPC Classifications
B; B01; B01D; B01D61/00; C; C08; C08G; C08G64/00; C08G64/04; C08G64/06; C08G64/08; C08G64/10; B01D71/00; B01D71/06; B01D71/50; C01; C01B; C01B13/00; C01B13/02; C01B13/0229; C01B13/0248; C01B13/0251; C01B13/0255; C01B21/00; C01B21/04; C01B21/0405; C01B21/0433; C01B21/0438; C01B21/0444; C01B32/00; C01B32/50; C07; C07C; C07C7/00; C07C7/144; C01B2210/00; C01B2210/0043; C01B2210/0045; C01B2210/0046
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
132 words
A gas separation membrane comprising a thin discriminating layer consisting predominantly of a carbonate polymer derived from a bisphenol corresponding to formula I wherein R at each occurrence is independently H, Cl, B r, or C l -C 4 alkyl and R l is -CO-, -S-, -S0 2 -, -0-, or a C l -C 6 divalent hydrocarbon radical, a C l -C 6 divalent fluorocarbon radical or inertly substituted C l -C 6 divalent hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups which are exclusively Br, Cl, or mixtures thereof said gas separation membrane exhibiting a separation factor for oxygen and nitrogen at the ambient temperature of at least 6.1.
Claim 2
Dependent Claim
132 words
A gas separation membrane comprising a thin discriminating layer consisting predominantly of a carbonate polymer derived from a bisphenol corresponding to formula I wherein R at each occurrence is independently H, Cl, B r, or C l -C 4 alkyl and R l is -CO-, -S-, -S0 2 -, -0-, or a C l -C 6 divalent hydrocarbon radical, a C l -C 6 divalent fluorocarbon radical or inertly substituted C l -C 6 divalent hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups which are exclusively Br, Cl, or mixtures thereof said gas separation membrane exhibiting a separation factor for oxygen and nitrogen at the ambient temperature of at least 6.1.
Claim 3
Dependent Claim
40 words
A membrane as claimed in Claim 1, wherein at least 30 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups with which are exclusively Br, Cl or mixtures thereof.
Claim 4
Dependent Claim
39 words
A membrane as claimed in Claim 2, wherein at least 50 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups which are exclusively Br, Cl, or mixtures thereof.
Claim 5
Dependent Claim
34 words
A membrane as claimed in Claim 3, wherein 100 weight percent of the moieties derived from formula I present in the discriminating layer bear R groups which are exclusively Br, Cl or mixtures thereof.
Claim 6
Dependent Claim
22 words
A membrane as claimed in any one of Claims 1 to 5, wherein R 1 is a C 1-6 divalent hydrocarbon radical.
Claim 7
Dependent Claim
34 words
A membrane as claimed in Claim 4, wherein the moiety derived from formula I is tetrabromobisphenol A and the gas separation membrane has a separation factor of at least 7.0 at the ambient temperature.
Claim 8
Dependent Claim
37 words
A membrane as claimed in any one of the preceding claims, which has been annealed by heating to a temperature above the beta transition temperature and t below the glass transition temperature to partially densify the polymer.
Claim 9
Independent Claim
67 words
A method of separating a gas from a gas mixture, said method comprising the steps of: (a) contacting the gas mixture with one side of a membrane of any one of Claims 1 to 7 while maintaining a pressure difference across the membrane with lower pressure being on the other side of the membrane, and (b) removing the permeated gas from the other side of the membrane.
Claim 10
Dependent Claim
21 words
A method as claimed in Claim 8, wherein the gas mixture contains oxygen and nitrogen and the permeated gas is oxygen.
Claim 11
Dependent Claim
23 words
A method as claimed in Claim 8, wherein the gas mixture contains carbon dioxide and methane and the permeated gas is carbon dioxide.
Claim 12
Independent Claim
48 words
A method as claimed in any one of Claims 8 to 10, wherein the gas mixture is contacted with the membrane at the temperature of from 0° to 80°C and the pressure difference across the membrane is maintained between 275 kPa (40 psia) and 1375 kPa (200 psia).
Claim 13
Dependent Claim
26 words
A method as claimed in Claim 11, wherein the pressure difference across the membrane is maintained between 650 kPa (95 psia) and 825 kPa (120 psia).
Claim 14
Dependent Claim
27 words
A method as claimed in Claim 11 or Claim 12, wherein the gas mixture is contacted with the membrane at a temperature of from 5° to 45°C.
Claim 15
Dependent Claim
21 words
Use of a membrane as claimed in any one of Claims 1 to 7 to separate gases by selective permeation therethrough.
References Cited (Backward Citations)
No citation records indexed.
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