| 摘要 |
PURPOSE: To recover HF in a state where HF can be recycled effectively from the economical point of view from 1,1,1,2-tetrafluoroethane containing a small amount of HF. CONSTITUTION: HP-containing 1,1,1,2-tetrafluoroethane 11 is brought into contact with an extractant 15 composed of an aqueous hydrofluoric acid solution of a HF content higher than the azeotropic point at a low temperature. The resultant mixture is allowed to separate into two layers and the lower layer composed of 1,1,1,2-tetrafluoroethane is taken out. Thereby, HF can economically be separated in a state where HF can effectively be recycled. The concentration of the aqueous hydrofluoric acid as the extractant is adjusted to 38 to 70wt.% and both the extraction operation and the separation operation into two layers are carried out preferably at 4-35 to 35°C. |
