US5346595A
Expired / Lapsed
US
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Process for the purification of a pentafluoroethane azeotrope
Assignee: Honeywell International Inc
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Filing: 1993-02-23
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Granted: 1994-09-13
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Expires: 2013-02-23
Abstract
Abstract The invention generally relates to a process for the purification of a component of a binary azeotrope in which the composition of the azeotrope changes by about 10 mole percent with pressure comprising: (a) subjecting a binary azeotrope to a distillation step in which most of one of the binary components is removed as distillate (distillate 1) with the bottoms (bottoms 1) enriched in the other component; (b) subjecting distillate 1 to at least one additional distillation step conducted at a different pressure in which most of the component recovered as bottoms 1 is removed as distillate 2 with the bottoms 2 enriched in the component enriched in distillate 1; (c) optionally repeating step (b) as many times as desired; and (d) recovering the desired purified component. The invention is particularly useful in the purification of pentafluoroethane in a pentafluoroethane/chloropentafluoroethane azeotrope.
Inventors
- 👤 Paul G. Clemmer
- 👤 Hsueh S. Tung
- 👤 Addison M. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:42
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C07C17/383; B; B01; B01D; B01D3/00; B01D3/14; Y; Y10; Y10S; Y10S203/00; Y10S203/13
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
131 words
A process for the purification of pentafluoroethane comprising: (a) subjecting a mixture comprising pentafluoroethane and at least about 0.5 mole % chloropentafluoroethane to a distillation step in which a composition enriched in one of pentafluoroethane or chloropentafluoroethane is removed as distillate 1 with a bottoms 1 being enriched in the other component and removed; (b) subjecting distillate 1 to at least one additional distillation step conducted at a different pressure in which the component enriched as bottoms 1 is removed as a distillate 2 and recycled as a feed to step (a), with a bottoms 2 being enriched in the component enriched in distillate 1 and removed; (c) optionally repeating step (a) and step (b) one or more times; and (d) recovering purified pentafluoroethane as either bottoms 1 or bottoms 2.
Claim 2
Dependent Claim
131 words
A process for the purification of pentafluoroethane comprising: (a) subjecting a mixture comprising pentafluoroethane and at least about 0.5 mole % chloropentafluoroethane to a distillation step in which a composition enriched in one of pentafluoroethane or chloropentafluoroethane is removed as distillate 1 with a bottoms 1 being enriched in the other component and removed; (b) subjecting distillate 1 to at least one additional distillation step conducted at a different pressure in which the component enriched as bottoms 1 is removed as a distillate 2 and recycled as a feed to step (a), with a bottoms 2 being enriched in the component enriched in distillate 1 and removed; (c) optionally repeating step (a) and step (b) one or more times; and (d) recovering purified pentafluoroethane as either bottoms 1 or bottoms 2.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said distillation steps are conducted in a single column.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein said distillation steps are conducted in two separate columns.
Claim 5
Dependent Claim
10 words
The process of claim 2 wherein step (c) is omitted.
Claim 6
Dependent Claim
30 words
The process of claim 4 wherein the first distillation step is conducted at a pressure of at least 50 psia and the second distillation is conducted at a lower pressure.
Claim 7
Dependent Claim
26 words
The process of claim 4 wherein said distillation steps are conducted at about 50 to about 300 psia and at less than about 35 psia respectively.
Claim 8
Dependent Claim
26 words
The process of claim 4 wherein said distillation steps are conducted at about 150 to about 220 psia and at less than about 20 psia respectively.
Claim 9
Dependent Claim
31 words
The process of claim 4 wherein the first distillation step is conducted at a pressure of less than about 35 psia and the second distillation is conducted at a higher pressure.
Claim 10
Dependent Claim
25 words
The process of claim 4 wherein said distillations are conducted at less than about 35 psia and from about 50 to about 300 psia respectively.
Claim 11
Dependent Claim
25 words
The process of claim 4 wherein said distillations are conducted at less than about 20 psia and from about 150 to about 220 psia respectively.
Claim 12
Dependent Claim
15 words
The process of claim 3 wherein said distillation steps are conducted as batch distillations steps.
Claim 13
Dependent Claim
16 words
The process of claim 3 wherein said distillation steps are conducted as a continuous distillation process.
Claim 14
Dependent Claim
10 words
The process of claim 3 wherein step (c) is omitted.
Claim 15
Dependent Claim
30 words
The process of claim 13 wherein the first distillation step is conducted at a pressure of at least 50 psia and the second distillation is conducted at a lower pressure.
Claim 16
Dependent Claim
26 words
The process of claim 13 wherein said distillation steps are conducted at about 50 to about 300 psia and at less than about 35 psia respectively.
Claim 17
Dependent Claim
26 words
The process of claim 13 wherein said distillation steps are conducted at about 150 to about 220 psia and at less than about 20 psia respectively.
Claim 18
Dependent Claim
31 words
The process of claim 13 wherein the first distillation step is conducted at a pressure of less than about 35 psia and the second distillation is conducted at a higher pressure.
Claim 19
Dependent Claim
26 words
The process of claim 13 wherein said distillation steps are conducted at less than about 35 psia and from about 50 to about 300 psia respectively.
Claim 20
Dependent Claim
25 words
The process of claim 13 wherein said distillations are conducted at less than about 20 psia and from about 150 to about 220 psia respectively.
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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) | 1997-09-12 | 1998-03-14 | 1998-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-12 | 2002-03-14 | 2002-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-12 | 2006-03-14 | 2006-09-13 | $7700.00 | Window Closed / Lapsed |