A method for mitigating hfc 245cb formation during hcfo 1233xf hydrofluorination to hcfc 244bb

摘要

The present process relates to a method for minimizing the formation of 1 1 1 2 2 pentafluoropropane in a liquid phase reaction of 2 chloro 3 3 3 trifluoropropene and HF in the presence of a hydrofluorination catalyst comprising: (a) reacting HF with sufficient amount of 2 chloro 3 3 3 trifluoropropene in the presence of a hydrofluorination catalyst under conditions effective to form 2 chloro 1 1 1 2 tetrafluoropropane the hydrofluorination catalyst being present in sufficient amounts to catalyze said reaction and the 2 chloro 1 1 1 2 tetrafluoropropane being formed with both a conversion of greater than 80% and a 1 1 1 2 2 pentafluoropropane selectivity lower than 20%; and (b) maintaining the 2 chloro 1 1 1 2 tetrafluoropropane being formed with both a conversion of about 80% or more and a 1 1 1 2 2 pentafluoropropane selectivity of about 20% or less by adding said hydrofluorination catalyst to the reactor in small increments.