GB285090A - Process for dehydrating vapour mixtures containing acetic anhydride and water - Google Patents

Abstract

285,090. I. G. Farbenindustrie Akt.- Ges. Feb. 11, 1927, [Convention date]. Grant of Patent opposed. Acetic anhydride.-Water vapour is removed from a vapour mixture containing acetic anhydride and the anhydride is simultaneously condensed by adding an indifferent solvent of low boiling point such as benzene, toluene, chloroform, trichlorethylene, or ethylene chloride or a mixture of them, to carry away the water vapour with or without the addition of a solvent of high boiling point such as o-dichlorbenzene, quinoline or quinaldine or a mixture of them to reduce the vapour tension of the anhydride. A separating column of the usual kind may be used, the low-boiling solvent being introduced both at the top and at the bottom. Mixed solvents mentioned are benzene and dichlorbenzene, benzene and quinoline, and benzene and trichlorethylene. The temperature of the receiver in which the anhydride condenses may be adjusted by heating if necessary to correspond with the nature and quantity of the solvents trickling down the column. The Specification as open to inspection under Sect. 91 (3) (a) states that a dephlegmator may be arranged at the top of the column. in which case the solvent is admitted only from below. This subject-matter does not appear in the Specification as accepted.