The Process of Isolation, Using Crystallization of Cis- and Trans-Isomers, of Perfluorodecalines from an Industrial Mixture of Electrochemical Fluorination of Napthaline

Abstract

The process of crystallization separation of an industrial mixture of perfluorinated cycloalkanes was considered. The content of target products, cis- and trans-isomers of perfluorodecalin (PFD), in all initial fractions of the investigated samples of the reaction mixture was at least 70 wt.%. Based on the experimental data, the dependences of the crystallization (partition) coefficients between the solid and mother liquor (Ds/l), the enrichment factor (ηs), and the separation factor (Fs) on the ratio of trans-PFD to cis-PFD, the ratio of mother liquor to solid, and crystallization temperature in the range −50–15 °C were obtained. It was shown that the values Ds/l and ηs depended significantly on the concentration of trans-PFD in the initial solution, and that the value of Fs decreased as the process temperature rose.

Keywords

• perfluorocycloalkanes
• perfluorodecalin
• cis-/trans-isomers
• crystallization
• separation
• purification