Patent ID: 9193649
Filing Date: 2015-11-24
Classification: C07C

Abstract:
1. A method for continuously purifying crude 2,3,3,3-tetrafluoropropene containing water and an organic impurity, the method comprising: using an apparatus having a distillation column with X stages (where “X” is an integer of 3 or larger, and the stage closest to a column top is the first stage) and a unit for cooling and condensing a distillate taken out from a column top of the distillation column; supplying the crude 2,3,3,3-tetrafluoropropene to an m-th stage (where “m” is an integer satisfying n+1≦m≦X and “n” is an integer satisfying 2≦n≦X−1) of the distillation column; recirculating at least part of the distillate cooled and condensed in the unit for cooling and condensing to an h-th stage (where “h” is an integer satisfying 1≦h≦n−1) of the distillation column; and taking out a liquid phase part of an n-th stage of the distillation column to obtain a purified product of 2,3,3,3-tetrafluoropropene.