SEPARATION OF HEXAFLUOROPROPYLENE FROM HEXAFLUOROPROPYLENE OXIDE

摘要

PROBLEM TO BE SOLVED: To separate hexafluoropropylene(HFP) from hexafluoropropylene oxide(HFPO) by directly distilling a mixture comprising HFP and HFPO under specific conditions. ;SOLUTION: A gas mixture comprising HFP and HFPO is introduced into a middle part of a distillation tower having a theoretical stage number of 30-200 and subsequently distilled under conditions comprising an inner pressure of 1-5kg/cm² (absolute pressure) and an operation temperature of -30 to 120°C to obtain highly pure HFPO and the highly pure HFP. The distillation conditions enable to enhance the relative volatility in a magnitude of approximately 0.01 and further enhance the distillatory separation efficiency. Since the HFP and the HFPO can be separated from each other without chemically reacting the mixture, using an extraction solvent and further requiring a multi-stage distillation tower, the separation method can easily industrially be performed and is advantageous also on environmental problems. The separated HFP can again be used as a raw material, when the HFP is oxidized into the HFPO.;COPYRIGHT: (C)1997,JPO