Patent ID: 8389779
Filing Date: 2013-03-05
Classification: C07C

Abstract:
1. A process for the preparation of 2,3,3,3-tetrafluoro- l -propene comprising the following steps: (i) hydrogenating hexafluoropropylene in the gas phase in the presence of a super-stoichiometric amount of hydrogen and of a hydrogenation catalyst in a reactor to yield 1,1,1,2,3,3-hexafluoropropane; (ii) dehydrofluorinating the 1,1,1,2,3,3-hexafluoropropane obtained in the preceding step in the presence of a dehydrofluorination catalyst or a water and potassium hydroxide mixture to yield 1,2,3,3,3-pentafluoro-1-propene; (iii) hydrogenating the 1,2,3,3,3-pentafluoro-1-propene obtained in the preceding step in the gas phase in the presence of a superstoichiometric amount of hydrogen and of a catalyst in a reactor to yield 1,1,1,2,3-pentafluoropropane; (iv) purifying the 1,1,1,2,3-pentafluoropropane obtained in the preceding step to a purity greater than 98% by weight; (v) dehydrofluorinating the purified 1,1,1,2,3-pentafluoropropane in the presence of a dehydrofluorination catalyst or a water and potassium hydroxide mixture, to yield 2,3,3,3-tetra-fluoro-1-propene; (vi) purifying the 2,3,3,3-tetrafluoro-1-propene obtained in the preceding step to yield the 2,3,3,3-tetrafluoro-1-propene in a purity greater than 99.5% by weight.