US4817392A
Expired / Lapsed
US
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Process for the production of argon
Assignee: Air Products and Chemicals Inc
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Filing: 1987-07-29
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Granted: 1989-04-04
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Expires: 2007-07-29
Abstract
Abstract The present invention is a process for the production and recovery of an O 2 -lean argon stream from a gas mixture containing argon and oxygen. The argon-containing gas mixture is initially treated in a cryogenic separation unit to produce a crude argon stream having an argon concentration between 80-98%. The crude argon stream is passed to a membrane separation unit where it is separated to produce an O 2 -lean argon stream and an O 2 - rich stream. The O 2 -rich stream is recycled tothe cryogenic separation unit and the O 2 -lean argon stream is recovered as product or futher purified.
Inventors
- 👤 Rakesh Agrawal
- 👤 Steven R. Auvil
- 👤 Jung S. Choe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:39
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/22; B01D53/229; C; C01; C01B; C01B23/00; F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04642; F25J3/04648; F25J3/04721; F25J3/04733; F25J2205/00; F25J2205/02; F25J2205/40; F25J2205/60; F25J2205/80; F25J2205/82; F25J2245/00; F25J2245/50
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
91 words
A process for producing an O 2 -lean argon stream comprising: (a) treating an argon-containing gas mixture in a cryogenic separation unit to produce a crude argon stream having an argon concentration between 80-98 volume % argon; (b) passing said crude argon stream to a membrane separation unit which is capable of separating oxygen from argon to produce an O 2 -lean argon stream and an O 2 -rich stream; (c) recycling the O 2 -rich stream to the cryogenic separation unit; and (d) recovering the O 2 -lean argon stream.
Claim 2
Dependent Claim
91 words
A process for producing an O 2 -lean argon stream comprising: (a) treating an argon-containing gas mixture in a cryogenic separation unit to produce a crude argon stream having an argon concentration between 80-98 volume % argon; (b) passing said crude argon stream to a membrane separation unit which is capable of separating oxygen from argon to produce an O 2 -lean argon stream and an O 2 -rich stream; (c) recycling the O 2 -rich stream to the cryogenic separation unit; and (d) recovering the O 2 -lean argon stream.
Claim 3
Dependent Claim
23 words
A process in accordance with claim 1 wherein said cryogenic separation unit is a cryogenic air separation unit with an argon distillation column.
Claim 4
Dependent Claim
24 words
A process in accordance with claim 1 wherein said O 2 -lean argon stream has an oxygen concentration of less than 3% by volume.
Claim 5
Dependent Claim
35 words
A process in accordance with claim 1 wherein said O 2 -lean argon stream recovered from the membrane separation unit is subsequently treated in a nitrogen removal unit to remove nitrogen present in said stream.
Claim 6
Dependent Claim
16 words
A process in accordance with claim 4 wherein the nitrogen removal unit is a cryogenic unit.
Claim 7
Dependent Claim
16 words
A process in accordance with claim 4 wherein the nitrogen removal unit is an adsoprtion unit.
Claim 8
Dependent Claim
28 words
A process in accordance with claim 6, wherein a portion of the O 2 -rich stream from the membrane separation unit is used to regenerate the adsorption unit.
Claim 9
Dependent Claim
22 words
A process in accordance with claim 7 wherein said O 2 -rich stream from the membrane separation unit is a permeate stream.
Claim 10
Dependent Claim
33 words
A process in accordance with claim 1 wherein the crude argon stream from the cryogenic separation unit is treated in a nitrogen removal unit prior to being passed to the membrane separation unit.
Claim 11
Dependent Claim
16 words
A process in accordance with claim 9 wherein the nitrogen removal unit is an adsorption unit.
Claim 12
Dependent Claim
28 words
A process in accordance with claim 10, wherein a portion of the O 2 -rich stream from the membrane separation unit is used to regenerate the adsorption unit.
Claim 13
Dependent Claim
24 words
A process in accordance with claim 1 wherein said O 2 -lean argon stream has an argon concentration of at least 97 volume %.
Claim 14
Dependent Claim
32 words
A process in accordance with claim 1 wherein the O 2 -lean argon stream recovered from the membrane separation unit is subsequently passed to a catalytic hydrogenation unit to further remove oxygen.
Claim 15
Dependent Claim
164 words
A process for producing an O 2 -lean argon stream comprising: (a) treating an argon-containing gas mixture in a cryogenic separation unit to produce a crude argon stream having an argon concentration between 80-98 volume % argon, and an essentially O 2 -free nitrogen stream; (b) treating said crude argon stream in a membrane separation unit which is capable of separating oxygen and argon to produce an O 2 -lean argon reject stream and an O 2 -rich permeate stream; (c) employing the essentially O 2 -free nitrogen stream from the cryogenic separation unit as a sweep stream on the permeate side of the membrane to reduce the partial pressure of O 2 on the permeate side of the membrane thereby increasing the flux of O 2 through the membrane; (d) recycling the O 2 -rich permeate stream along with the nitrogen sweep stream to the cryogenic separation unit; and (e) recovering the O 2 -lean, argon reject stream from the membrane separation unit.
Claim 16
Dependent Claim
164 words
A process for producing an O 2 -lean argon stream comprising: (a) treating an argon-containing gas mixture in a cryogenic separation unit to produce a crude argon stream having an argon concentration between 80-98 volume % argon, and an essentially O 2 -free nitrogen stream; (b) treating said crude argon stream in a membrane separation unit which is capable of separating oxygen and argon to produce an O 2 -lean argon reject stream and an O 2 -rich permeate stream; (c) employing the essentially O 2 -free nitrogen stream from the cryogenic separation unit as a sweep stream on the permeate side of the membrane to reduce the partial pressure of O 2 on the permeate side of the membrane thereby increasing the flux of O 2 through the membrane; (d) recycling the O 2 -rich permeate stream along with the nitrogen sweep stream to the cryogenic separation unit; and (e) recovering the O 2 -lean, argon reject stream from the membrane separation unit.
Claim 17
Dependent Claim
23 words
A process in accordance with claim 14 wherein said cryogenic separation unit is a cryogenic air separation unit with an argon distillation column.
Claim 18
Dependent Claim
25 words
A process in accordance with claim 14 wherein said O 2 -lean argon reject stream has an oxygen concentration of less than 3% by volume.
Claim 19
Dependent Claim
36 words
A process in accordance with claim 14 wherein said O 2 -lean argon reject stream recovered from the membrane separation unit is subsequently treated in a nitrogen removal unit to remove nitrogen present in said stream.
Claim 20
Dependent Claim
16 words
A process in accordance with claim 17 wherein the nitrogen removal unit is a cryogenic unit.
Claim 21
Dependent Claim
16 words
A process in accordance with claim 17 wherein the nitrogen removal unit is an adsorption unit.
Claim 22
Dependent Claim
29 words
A process in accordance with claim 19, wherein a portion of the O 2 -rich permeate stream from the membrane separation unit is used to regenerate the adsorption unit.
Claim 23
Dependent Claim
25 words
A process in accordance with claim 14 wherein said O 2 -lean argon reject stream has an argon concentration of at least 97 volume %.
Claim 24
Dependent Claim
33 words
A process in accordance with claim 14 wherein the O 2 -lean argon reject stream recovered from the membrane separation unit is subsequently passed to a catalytic hydrogenation unit to further remove oxygen.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |