| 摘要 |
<p>PURPOSE:To efficiently remove an unsaturated compound in 2,2-dichloro-1,1- trifluoroethane useful as refrigerants, propellants, foaming agents, solvents, trifluoroacetic acid, etc., by selectively hydrogenating the aforementioned unsaturated compound. CONSTITUTION:2,2-Dichloro-1,1,1-trifluoroethane (HFC-123) containing an unsaturated compound, especially 2-chloro-1,1,1,4,4,4-hexafluorobutene-2 as an impurity in the vapor phase is reacted with hydrogen in an amount of preferably 1-200mol based on 1mol aforementioned unsaturated compound in the presence of a platinum catalyst supported on a carrier such as preferably active carbon, alumina, silica gel, titanium oxide or zirconia, normally at 30-300 deg.C, preferably 70-150 deg.C temperature to selectively hydrogenate the above-mentioned impurity in the HFC-123. Furthermore, the hydrogenated substance, as necessary, is removed by rectification to reduce the above-mentioned impurity in the HFC-123.</p> |
