US4861361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Argon and nitrogen coproduction process
Assignee: Messer LLC
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Filing: 1988-09-27
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Granted: 1989-08-29
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Expires: 2008-09-27
Abstract
Abstract Argon and nitrogen are separated from a gaseous stream containing them in combination with oxygen in a three-step process comprising introducing the gaseous stream under pressure to a noncryogenic separator to produce therein a stream enriched in nitrogen and argon, introducing said stream into a cryogenic distillation column to produce a high purity nitrogen product. An argon-rich side stream withdrawn from the cryogenic distillation column is introduced into a pressure swing adsorption unit to provide a crude argon product containing 97 percent or more of argon. The first noncryogenic separator may be a pressure swing adsorption unit or a gas diffusion zone.
Inventors
- 👤 Ravi Jain
- 👤 Alberto LaCava
- 👤 Mark J. Andrecovich
- 👤 Donald L. MacLean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:28
CPC Classifications
C; C01; C01B; C01B23/00; F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04248; F25J3/04278; F25J3/04333; F25J3/04351; F25J3/04357; F25J3/044; F25J3/04636; F25J3/04642; F25J3/04648; F25J2200/00; F25J2200/50; F25J2205/00; F25J2205/60; F25J2205/80; F25J2245/00; F25J2245/02; F25J2270/00; F25J2270/12; F25J2270/14; F25J2270/40; F25J2270/66; Y; Y02; Y02P; Y02P20/00; Y02P20/10; Y02P20/129
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
124 words
A process for the coproduction of purified nitrogen and argon from a gaseous stream containing them in combination with at least oxygen comprising: (a) introducing said stream under pressure into a noncryogenic separation means and recovering therefrom a gaseous stream enriched in nitrogen and argon; (b) introducing said enriched stream into a distillation column; (c) withdrawing a purified nitrogen product stream from the top of said column, an oxygen-rich stream from the bottom of said column and an argon-enriched side stream from an intermediate point in said column where there is a relatively high argon content; (d) introducing said side stream into a pressure swing adsorption unit to further enrich said stream in argon; and (e) withdrawing said further enriched argon stream as product.
Claim 2
Dependent Claim
124 words
A process for the coproduction of purified nitrogen and argon from a gaseous stream containing them in combination with at least oxygen comprising: (a) introducing said stream under pressure into a noncryogenic separation means and recovering therefrom a gaseous stream enriched in nitrogen and argon; (b) introducing said enriched stream into a distillation column; (c) withdrawing a purified nitrogen product stream from the top of said column, an oxygen-rich stream from the bottom of said column and an argon-enriched side stream from an intermediate point in said column where there is a relatively high argon content; (d) introducing said side stream into a pressure swing adsorption unit to further enrich said stream in argon; and (e) withdrawing said further enriched argon stream as product.
Claim 3
Dependent Claim
31 words
A process in accordance with claim 1, wherein said gaseous stream is introduced into the noncryogenic separation means in step (a) at a pressure of from about 30 to 200 psig.
Claim 4
Dependent Claim
18 words
A process in accordance with claim 1, wherein said noncryogenic separation means is a pressure swing adsorption unit.
Claim 5
Dependent Claim
17 words
A process in accordance with claim 1, wherein said noncryogenic separation means is a gas diffusion zone.
Claim 6
Dependent Claim
24 words
A process in accordance with claim 1, wherein the enriched stream formed in step (a) contains from about 1 to 10 percent of oxygen.
Claim 7
Dependent Claim
37 words
A process in accordance with claim 1, wherein the enriched stream formed in step (a) is cooled by heat exchange against the nitrogen product stream and oxygen-rich stream prior to being introduced into said cryogenic distillation column.
Claim 8
Dependent Claim
28 words
A process in accordance with claim 1, wherein a portion of the nitrogen product stream withdrawn from said cryogenic distillation column is returned to said column as reflux.
Claim 9
Dependent Claim
28 words
A process in accordance with claim 1, wherein a portion of the oxygen-rich stream withdrawn from the bottom of said cryogenic distillation column is recycled to the column.
Claim 10
Dependent Claim
18 words
A process in accordance with claim 8, wherein the remainder of said oxygen-rich stream is taken as product.
Claim 11
Dependent Claim
33 words
A process in accordance with claim 1, wherein the refrigeration for said process is provided by a refrigeration cycle utilizing nitrogen withdrawn from the nitrogen product stream as the heat pump fluid therein.
Claim 12
Dependent Claim
54 words
A process in accordance with claim 1, wherein, in step (d), an oxygen-rich waste stream is formed in said pressure swing adsorption unit and said stream is returned to an intermediate point in said cryogenic distillation column wherein the composition of the gas mixture in the column is similar to that of said stream.
Claim 13
Dependent Claim
35 words
A process in accordance with claim 11, wherein said waste stream and said argon product are passed in heat exchange with said argon-enriched side stream prior to introduction thereof into said pressure swing adsorption unit.
References Cited (Backward Citations)
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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) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |