Patent ID: 9359274
Filing Date: 2016-06-07
CPC Classification: B01J,C07C

Claim Text:
1. A method for producing 1,3,3,3-tetrafluoropropene comprising the steps of: causing a dehydrofluorination reaction of 1,1,1,3,3-pentafluoropropane in the gas phase and in the presence of a catalyst thereby producing 1,3,3,3-tetrafluoropropene, wherein the dehydrofluorination reaction is carried out at a pressure inside the reaction system of from 0.001 to 90 kPa (absolute pressure) at a reaction temperature ranging from 250 to 600° C.; separating and removing hydrogen fluoride from a reaction mixture produced by the dehydrofluorination reaction of 1,1,1,3,3-pentafluoropropane, wherein the reaction mixture contains 1,3,3,3-tetrafluoropropene, unreacted 1,1,1,3,3-pentafluoropropane, organic impurities and hydrogen fluoride; subjecting the mixture obtained after removing hydrogen fluoride to distillation, wherein a fraction obtained by distillation comprises: trans-1,3,3,3-tetrafluoropropene; and cis-1,3,3,3-tetrafluoropropene containing 1,1,1,3,3-pentafluoropropane; and reacting the cis-1,3,3,3-tetrafluoropropene containing 1,1,1,3,3-pentafluoropropane with a base and then performing distillation, to obtain cis-1,3,3,3-tetrafluoropropene which does not substantially contain 1,1,1,3,3-pentafluoropropane.