US4906796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying 1,1,1,2-tetrafluoroethane
Assignee: Honeywell International Inc
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Filing: 1989-03-08
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Granted: 1990-03-06
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Expires: 2009-03-08
Abstract
Abstract R-1122 (2-chloro-1,1-difluoro-ethylene) can be substantially removed from a stream of R-134a over a zeolite or carbon molecular sieve having a mean pore size of about 3.8 to 4.8 Angstroms. Preferred are 5A synthetic zeolites or calcium chabazite.
Inventors
- 👤 Stephen F. Yates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:19
CPC Classifications
C; C07; C07C; C07C19/00; C07C19/08; C07C17/00; C07C17/38; C07C17/389
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
62 words
A process for removing impurities from 1,1,1,2-tetrafluoroethane (R-134a) containing about 50-10,000 ppm by weight of 2-chloro-1,1-difluoro-ethylene (R-1122) comprising passing said 1,1,1,2-tetrafluoroethane over a zeolite having a mean pore size between 3.8 and 4.8 Angstroms at a temperature of -10° to 100° C. and a pressure of 100 to 860 kPa and recovering 1,1,1,2-tetrafluoroethane containing less than 10 ppm by weight of 2-chloro-1,1-difluoro-ethylene.
Claim 2
Dependent Claim
62 words
A process for removing impurities from 1,1,1,2-tetrafluoroethane (R-134a) containing about 50-10,000 ppm by weight of 2-chloro-1,1-difluoro-ethylene (R-1122) comprising passing said 1,1,1,2-tetrafluoroethane over a zeolite having a mean pore size between 3.8 and 4.8 Angstroms at a temperature of -10° to 100° C. and a pressure of 100 to 860 kPa and recovering 1,1,1,2-tetrafluoroethane containing less than 10 ppm by weight of 2-chloro-1,1-difluoro-ethylene.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said zeolite is a 5A synthetic zeolite.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said zeolite is calcium chabazite.
Claim 5
Dependent Claim
31 words
The process of claim 1 wherein said zeolite is a fixed bed of zeolite particles and the gas hourly space velocity of said 1,1,1,2-tetrafluoroethane is 130 to 3600 hr -1 .
Claim 6
Dependent Claim
25 words
The process of claim 1 wherein said zeolite is calcined to provide a loss on ignition at 900° C. of less than 6% by weight.
Claim 7
Dependent Claim
31 words
The process of claim 1 wherein said zeolite is a fixed bed of zeolite particles and the liquid hourly space velocity of said 1,1,1,2-tetrafluoroethane is 1 to 30 hr -1 .
Claim 8
Dependent Claim
62 words
A process for removing impurities from 1,1,1,2-tetrafluoroethane containing about 500-10000 ppm by weight of 2-chloro-1,1-difluoro-ethylene comprising passing said 1,1,1,2-tetrafluoroethane over a carbon molecular sieve having a mean pore size between 3.8 and 4.8 Angstroms at a temperature of -10° to 100° C. and a pressure of 100 to 860 kPa and recovering 1,1,1,2-tetrafluoroethane containing less than 10 ppm by weight of 2-chloro-1,1-difluoro-ethylene.
Claim 9
Dependent Claim
62 words
A process for removing impurities from 1,1,1,2-tetrafluoroethane containing about 500-10000 ppm by weight of 2-chloro-1,1-difluoro-ethylene comprising passing said 1,1,1,2-tetrafluoroethane over a carbon molecular sieve having a mean pore size between 3.8 and 4.8 Angstroms at a temperature of -10° to 100° C. and a pressure of 100 to 860 kPa and recovering 1,1,1,2-tetrafluoroethane containing less than 10 ppm by weight of 2-chloro-1,1-difluoro-ethylene.
Claim 10
Dependent Claim
33 words
The process of claim 7 wherein said carbon molecular sieve is a fixed bed of carbon particles and the gas hourly space velocity of said 1,1,1,2-tetrafluoroethane is 130 to 3600 hr -1 .
Claim 11
Dependent Claim
33 words
The process of claim 7 wherein said carbon molecular sieve is a fixed bed of carbon particles and the liquid hourly space velocity of said 1,1,1,2-tetrafluoroethane is 1 to 30 hr -1 .
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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) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |