Process for purifying 1,1,1,2-tetrafluoroethane
AssigneeAllied-Signal Inc.
InventorStephen F. Yates
Life of this patent
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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.
Claims9
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.degree. to 100.degree. 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.
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.degree. to 100.degree. 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.
Dependencies are inferred from the claim text.