Claims
- 1. A process for the removal of 1-chloro-2,2-difluoroethylene from 1,1,1,2-tetrafluoroethane which comprises contacting 1,1,1,2-tetrafluoroethane containing 1-chloro-2,2-difluoroethylene with a zeolite having a mean pore size in the range of 3.5 .ANG. to 4.8 .ANG. and having potassium as the predominant counter cation.
- 2. A process as claimed in claim 1 in which the zeolite has a mean pore size in the range from about 3.5 .ANG. to about 4.5 .ANG..
- 3. A process as claimed in claim 1 in which the zeolite has a mean pore size in the range from about 3.6 .ANG. to about 4.2 .ANG..
- 4. A process for the removal of 1-chloro-2,2-difluoroethylene from 1,1,1,2-tetrafluoroethane by contacting 1,1,1,2-tetrafluoroethane containing 1-chloro-2,2-difluoroethylene with a zeolite having a mean pore size in the range of about 3.5 .ANG. to about 4.8 .ANG. and having potassium as a counter cation wherein the zeolite is produced by potassium-cation exchange with a starting zeolite comprising at least one of errionite, offrotite and chabazite.
- 5. A process as claimed in claim 4 in which the starting zeolite comprises AW-500 zeolite.
- 6. A process as claimed in claim 4 in which the degree of cation-exchange is at least 30%.
- 7. A process as claimed in claim 4 in which the degree of cation-exchange is at least 50%.
- 8. A process as claimed in claim 1 in which the 1,1,1,2-tetrafluoroethane containing 1-chloro-2,2-difluoroethylene in the liquid or vapour phase is passed over a bed of zeolite particles.
- 9. A process as claimed in claim 1 in which the temperature is in the range from about -30.degree. C. to about 100.degree. C.
- 10. A process as claimed in claim 1 wherein the 1,1,1,2-tetrafluoroethane to be contacted with the zeolite contains from about 10 to about 10000 ppm of 1-chloro-2,2-difluoroethylene and whereby 1,1,1,2-tetrafluoroethane containing less than 5 ppm of 1-chloro-2,2-difluoroethylene is recovered.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9116777.5 |
Aug 1991 |
GBX |
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Parent Case Info
This is a continuation of application Ser. No. 07/918,681, filed on Jul. 27, 1992, which was abandoned.
US Referenced Citations (3)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0511612 |
Nov 1992 |
EPX |
Non-Patent Literature Citations (1)
Entry |
Rabo Zeolite Chemistry and Catalysis ACS monograph 171 (1976) p. 34. |
Continuations (1)
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Number |
Date |
Country |
Parent |
918681 |
Jul 1992 |
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