Patent ID: 7468467
Filing Date: 2008-12-23
Classification: C07C

Abstract:
1. Process for obtaining a hydrofluoroalkane comprising at least three carbon atoms, which is purified of organic impurities including (chloro)fluoro olefins, according to which the hydrofluoroalkane containing organic impurities is subjected to at least one purification treatment which allows an effective reduction of the content of the olefinic impurities chosen from (a) a treatment with chlorine in the presence of a initiator wherein said initiator is an electromagnetic radiation comprising at least one fraction of wavelengths less than 280 nm; (b) a reaction with hydrogen fluoride; (c) a distillation in which the purified hydrofluoroalkane is removed from the top of the distillation column or from the side and wherein the distillation column has at least 10 theoretical plates; (d) an extractive distillation which is carried out in the presence of at least one extractant selected from the group consisting of (hydro)chlorocarbon, (hydro)fluorocarbon, hydrochlorofluorocarbon, hydrocarbon, ketone, ether, ester, nitrile, hydrogen chloride and carbon dioxide; (f) a reaction with a compound containing oxygen wherein said compound containing oxygen is selected from the group is an oxygenated acid, an organic peroxide, an inorganic peroxide, a peroxide salt or a peracid; (g) a gas-phase reaction with a reagent capable of reacting with at least some of the organic impurities, with the exception of a reaction with elemental chlorine wherein said reagent is hydrogen, hydrogen chloride or hydrogen fluoride; and (h) a gas-phase reaction with a reagent capable of reacting with at least some of the organic impurities, with the exception of a reaction with elemental chlorine and wherein the reaction is a catalytic hydrogenation.