US4654055A
Expired / Lapsed
US
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Asymmetric gas separation membranes
Assignee: Permea Inc
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Filing: 1983-06-30
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Granted: 1987-03-31
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Expires: 2003-06-30
Abstract
Abstract Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.
Inventors
- 👤 Raymond F. Malon
- 👤 Anthony Zampini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:11
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
90 words
An asymmetric gas separation membrane exhibiting substantially improved gas separation selectivity comprising, a preformed asymmetric separation membrane of material having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base, wherein with respect to the at least one gas, the base contacted membrane exhibits a separation factor significantly greater than the separation factor exhibited by the membrane before base contact.
Claim 2
Dependent Claim
90 words
An asymmetric gas separation membrane exhibiting substantially improved gas separation selectivity comprising, a preformed asymmetric separation membrane of material having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base, wherein with respect to the at least one gas, the base contacted membrane exhibits a separation factor significantly greater than the separation factor exhibited by the membrane before base contact.
Claim 3
Dependent Claim
27 words
The improved asymmetric gas separation membrane of claim 1 wherein the separation factor for the one gas of the gas mixture is increased by at least 100%.
Claim 4
Dependent Claim
36 words
The improved asymmetric gas separation membrane of claim 2 wherein the improvement in separation factor for the one gas of the gas mixture is accomplished with a reduction in permeability of not more than about 50%.
Claim 5
Dependent Claim
46 words
The improved asymmetric gas separation membrane of claim 1 wherein the material of the asymmetric membrane is comprised of a material selected from the group consisting of polymers and copolymers and substituted polymers of polyethers, polysulfones, polyaryleneoxides, polyethersulfones, cellulose esters, and copolymers of styrene and acrylonitrile.
Claim 6
Dependent Claim
33 words
The improved asymmetric gas separation membrane of claim 1 wherein the at least one gas is selected from the group consisting of carbon monoxide, nitrogen, oxygen, helium, methane, ethane, hydrogen, and carbon dioxide.
Claim 7
Dependent Claim
40 words
The improved asymmetric gas separation membrane according to claim 1 wherein the separation factor for the separation of hydrogen from a gaseous mixture comprised of hydrocarbons of 1 to about 5 carbon atoms is improved by at least about 200%.
Claim 8
Dependent Claim
48 words
The improved asymmetric gas separation membrane according to claim 6 wherein the separation factor for the separation of hydrogen from a gaseous mixture comprised of hydrocarbons of 1 to about 5 carbon atoms is greater than the intrinsic separation factor of the membrane material in dense film form.
Claim 9
Dependent Claim
38 words
The improved asymmetric gas separation membrane according to claim 1 wherein the improved contacted asymmetric membrane exhibits a separation factor for the separation of CO 2 from methane of at least about 200% over the untreated asymmetric membrane.
Claim 10
Dependent Claim
20 words
The improved asymmetric gas separation membrane according to claim 1 wherein the Bronsted-Lowry base is mixed with a Lewis base.
Claim 11
Dependent Claim
109 words
A process for improving the selectivity of an asymmetric gas separation membrane of material exhibiting selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture comprising: contacting the preformed asymmetric gas separation membrane with an effective amount of a Bronsted-Lowry base which is volatile at ambient conditions, the base being contacted with one or both surfaces of the membrane for a period sufficient with respect to the at least one gas to improve the separation factor significantly greater than the separation factor exhibited by the membrane before acid treatment; and removing the residual base through vaporization.
Claim 12
Dependent Claim
109 words
A process for improving the selectivity of an asymmetric gas separation membrane of material exhibiting selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture comprising: contacting the preformed asymmetric gas separation membrane with an effective amount of a Bronsted-Lowry base which is volatile at ambient conditions, the base being contacted with one or both surfaces of the membrane for a period sufficient with respect to the at least one gas to improve the separation factor significantly greater than the separation factor exhibited by the membrane before acid treatment; and removing the residual base through vaporization.
Claim 13
Dependent Claim
103 words
A multicomponent gas separation membrane exhibiting improved gas separation selectivity and resistance to hydrocarbons degradation, comprising, an asymmetric membrane coated with one or more materials, said membrane having selective permeation of at least one of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base, wherein with respect to the at least one gas, the base contacted multicomponent gas separation membrane exhibits an improved separation factor greater than the separation factor exhibited by the multicomponent gas separation membrane before base treatment.
Claim 14
Dependent Claim
103 words
A multicomponent gas separation membrane exhibiting improved gas separation selectivity and resistance to hydrocarbons degradation, comprising, an asymmetric membrane coated with one or more materials, said membrane having selective permeation of at least one of a gaseous mixture over that of one or more remaining gases of the gaseous mixture which has been contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base, wherein with respect to the at least one gas, the base contacted multicomponent gas separation membrane exhibits an improved separation factor greater than the separation factor exhibited by the multicomponent gas separation membrane before base treatment.
References Cited (Backward Citations)
US3657113A
Cited
US3616607A
Cited
US3775308A
Cited
US3980456A
Cited
US4230463A
Cited
US4323454A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-30 | 1990-09-29 | 1991-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-30 | 1994-09-29 | 1995-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-30 | 1998-09-29 | 1999-03-31 | $7700.00 | Window Closed / Lapsed |