CATALYTIC GAS PHASE FLUORINATION OF 1230xa TO 1234yf

摘要

The invention is directed to a process for preparing 2, 2, 2, 3-tetrafluoropropene (1234yf), comprising : (i) contacting 1, 1, 2, 3-tetrachloropropene (1230xa) with hydrogen fluoride HF in gas phase in the presence of a fluorination catalyst under conditions sufficient to produce a reaction mixture; (ii) separating the reaction mixture into a first stream comprising HCl, 2,2,2,3- tetraf luoropropene (1234yf) and a second stream comprising HF, 2-chloro-3, 3, 3- trif luoro-1-propene (1233xf) and 1,1,1,2, 2-pentaf luoropropane (245cb); (iii) recycling at least a part of the second stream at least in part back to step (i).