SEPARATION OF MIXTURE CONTAINING HYDROGEN FLUORIDE AND 1,1,1,3,3-PENTAFLUOROBUTANE AND SYNTHESIS OF 1,1,1,3,3- PENTAFLUOROBUTANE

摘要

PROBLEM TO BE SOLVED: To secure the effective utilization of raw materials, especially of hydrogen fluoride and to effectively separate hydrogen fluoride from 1,1,1,3,3- pentafluorobutane in a reaction product mixture containing them by distilling the mixture twice or more. SOLUTION: When separating at least one kind of components from a mixture containing both (A) 1,1,1,3,3-pentafluorobutane and (B) hydrogen fluoride, the mixture is subjected to distillation at least twice. The first distillation is carried out under a first pressure and the second one is carried out under a second pressure other than that in the first distillation in order to recover at least one fraction rich in the component A and at least one fraction rich in the component B. It is preferable that the first distillation is carried out at a higher pressure (especially 6-11 bars), the second distillation is carried out at a lower pressure (especially 0.5-3 bars) and the fraction substantially comprising the component A is recovered from the lowest part of the second distillation.