METHOD OF PRODUCING 2,3,3,3-TETRAFLUOROPROPENE BY GAS-PHASE FLUORINATION OF PENTACHLOROPROPANE Russian patent published in 2015 - IPC C07C17/20 C07C17/25 C07C17/383 C07C17/42 C07C21/18 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for catalytic gas-phase fluorination of a product of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane into a 2,3,3,3-tetrafluoropropene product. The method comprises the following steps: (i) contacting 1,1,1,2,3-pentachloropropane (HCC 240db) and/or 1,1,2,2,3-pentachloropropane (HCC 240aa) with hydrogen fluoride HF in a gas phase in the presence of a fluorination catalyst in conditions that are sufficient for obtaining a reaction mixture containing 2,3,3,3-tetrafluoropropene (1234yf); (ii) dividing the reaction mixture into a first stream containing 2,3,3,3-tetrafluoropropene (1234yf), and a second stream containing 2-chloro-3,3,3-trifluoro-1-propene (1233xf) and 1,1,1,2,2-pentafluoropropane (245cb); (iii) recycling at least a portion of the second stream at least partially to step (i).

EFFECT: use of the present method enables to obtain an end product in a single reaction step, which ensures acceptable process performance.

21 cl, 4 tbl, 7 ex, 2 dwg