US5064446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing high purity light gas by multiple-step gas separation
Assignee: Ube Corp
•
Filing: 1988-05-26
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Granted: 1991-11-12
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Expires: 2008-05-26
Abstract
Abstract A purified light gas consisting of hydrogen or helium and having a high purity of, for example, 99.99% or more is prepared from a feed gas containing at least 90 molar % or more of H2 or He and substantially no CO2 by gas-separating the feed gas through a plurality of gas-separating membrane modules each comprising at least one polymeric gas-separating membrane and having a gas-permeating ratio PA/PCH4 of 100 or more, wherein PA is a permeating rate of the light gas and PCH4 is a permeating rate of methane gas, in such a manner that each fraction of the feed gas permeated through and delivered from a preceding membrane module is fed to a next membrane module under the pressure, per se, of the delivered fraction of the feed gas without pressurizing the delivered fraction.
Inventors
- 👤 Yoshihiro Kusuki
- 👤 Kazuhiko Ishihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:40
CPC Classifications
C; C01; C01B; C01B23/00; C01B23/001; C01B23/0036; C01B23/0042; C01B23/0047; B; B01; B01D; B01D53/00; B01D53/22; B01D53/225; B01D53/226; C01B3/00; C01B3/50; C01B3/501; C01B2203/00; C01B2203/04; C01B2203/0405; C01B2203/0465; C01B2203/0475; C01B2210/00; C01B2210/0029; C01B2210/0031; Y; Y02; Y02P; Y02P20/00; Y02P20/151
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
166 words
A method for preparing a high purity light gas consisting of a member selected from the group consisting of hydrogen and helium, comprising subjecting a feed gas containing at least 90 molar % of a light gas consisting of a member selected from the group consisting of hydrogen and helium and substantially no carbon dioxide to a gas-separating procedure in 2 to 5 steps through 2 to 5 gas-separating membrane modules, each of said gas-separating membrane modules comprising at least one aromatic imide-polymer gas-separating membrane and having a gas permeating rate ratio P A /P CH4 of 100 or more, wherein P A represents a permeating rate of hydrogen or helium and P CH4 represents a permeating rate of methane gas, in such a manner that a fraction of said feed gas, which has permeated through and has been delivered from a preceding gas-separating membrane module, is fed to a next gas-separating membrane module without increasing the pressure of the delivered fraction of the feed gas.
Claim 2
Independent Claim
166 words
A method for preparing a high purity light gas consisting of a member selected from the group consisting of hydrogen and helium, comprising subjecting a feed gas containing at least 90 molar % of a light gas consisting of a member selected from the group consisting of hydrogen and helium and substantially no carbon dioxide to a gas-separating procedure in 2 to 5 steps through 2 to 5 gas-separating membrane modules, each of said gas-separating membrane modules comprising at least one aromatic imide-polymer gas-separating membrane and having a gas permeating rate ratio P A /P CH4 of 100 or more, wherein P A represents a permeating rate of hydrogen or helium and P CH4 represents a permeating rate of methane gas, in such a manner that a fraction of said feed gas, which has permeated through and has been delivered from a preceding gas-separating membrane module, is fed to a next gas-separating membrane module without increasing the pressure of the delivered fraction of the feed gas.
Claim 3
Dependent Claim
33 words
The method as claimed in claim 1, wherein said high purity light gas has a purity of 99.99% or more, when a content of water is omitted from the calculation of the purity.
Claim 4
Dependent Claim
16 words
The method as claimed in claim 1, wherein said feed gas substantially does not contain moisture.
Claim 5
Dependent Claim
65 words
The method as claimed in claim 1, wherein the feed gas to be fed to a first step of gas-separating membrane module has a pressure adjusted to an elevated level, with the result that a fraction of the feed gas, which has permeated through and has been delivered from a last step of gas-separating membrane module, exhibits a pressure of 30 mmHg Abs or more.
Claim 6
Dependent Claim
31 words
The method as claimed in claim 4, wherein the fraction of the feed gas delivered from the last step of the gas-separating membrane module exhibits at least an ambient atmospheric pressure.
Claim 7
Dependent Claim
41 words
The method as claimed in claim 1, wherein each fraction of the feed gas which has not permeated through each gas-separating membrane module is fed to an additional gas-separating polymeric membrane module to recover the light gas from the non-permeated fraction.
Claim 8
Dependent Claim
51 words
The method as claimed in claim 1, wherein a fraction of the feed gas which has not permeated through the gas-separating membrane module in any of from the second to the last steps, is returned to a preceding step gas-separating membrane module, to recover the light gas from the non-permeated fraction.
Claim 9
Dependent Claim
24 words
The method as claimed in claim 1, wherein the gas-separating procedure is carried out at a temperature of from -70° C. to 120° C.
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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) | 1994-11-11 | 1995-05-13 | 1995-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-11 | 1999-05-13 | 1999-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-11 | 2003-05-13 | 2003-11-12 | $7700.00 | Window Closed / Lapsed |