摘要 |
The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3- pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3- pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HC1, 2-chloro-3,3,3- trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HC1 and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3- trifluoropropene and optionally 1,1,1,2,2- pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HC1, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a). |