摘要 |
<p>1,1,1,2-Tetrafluoroethane (R134a) is purified to remove 50-10,000 wt. ppm of 2-chloro-1,1-difluoroethylene (R1122) by contacting with a zeolite or carbon molecular sieve having an average pore diameter of 3.8 to 4.8 Angstroms. The zeolite or carbon molecular sieve is regenerated by inert gas stripping residual R134a, followed by a regeneration at elevated temperatures using an inert gas. Regeneration of the zeolite or carbon molecular sieve is accomplished without the substantial reduction in capacity for impurities.</p> |