| abstract |
To remove olefinic impurities (in in particular 1-chloro-2,2-difluoroethylene and the polyfluoropropenes) present in 1,1,1,2-tetrafluoroethane (F134a) raw, treated in the gas phase, in the presence of a fluorination catatlyzer, a gaseous mixture of crude F134a, hydrofluoric acid and oxygen or air at a temperature between 200 and 350 ° C and under pressure between atmospheric pressure and 2.5 MPa, the HF / F134a molar ratio being between 0.05 and 0.5 and the O2 / F134a molar ratio between 0.001 and 0.1. This process allows efficient and economical purification of F134a. |