Process for perfluorocycloalkane purification

Abstract

A process is disclosed for recovering at least one perfluorocycloalkane selected from the group consisting of octafluorocyclobutane, hexafluoro-bis(trifluoromethyl)cyclobutane (1,2 and 1,3; cis and trans), and heptafluoro(trifluoromethyl)cyclobutane from a mixture comprising (a) the perfluorocycloalkane, (b) olefinic impurity and, optionally, (c) saturated chlorine-containing impurity selected from the group consisting of chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons and mixtures thereof. The process involves (1) contacting the mixture with hydrogen in the presence of a hydrogenation catalyst under conditions suitable for converting at least a portion of the olefinic impurity to a saturated impurity containing at least one fluorine substituent less than the olefin impurity and reducing the chlorine content of at least a portion of the saturated chlorine-containing impurity (if present), and (2) separating said at least one perfluorocycloalkane from the products produced during the hydrogenation of (1).

Dependencies are inferred from the claim text.