GB556038A - Dehydrohalogenation of halohydrins to form epoxides - Google Patents

Abstract

556,038. Production of organic epoxides. SHELL DEVELOPMENT CO. Sept. 12, 1941, No. 11723. Convention date, Sept. 17, 1940. [Class 2 (iii)] Organic epoxides, e.g. olefine oxides, hydroxy epoxides, halogenated epoxides, or polyepoxides, are produced by the reaction of a halohydrin. e.g. an olefine halohydrin, a glycerine halohydrin, or a glycerine halohydrin monoether, with a base or basic-acting compound, by separately introducing the two reactants into a reaction zone where the mixture is directly contacted with live steam at, e.g. sub- or super-atmospheric pressure so that the organic epoxide is vaporized and separated. from the reaction mixture substantially as soon as it is formed therein, and continuously rectifying the vaporous mixture out of contact with the basic compound to separate unreacted halohydrin from the organic epoxide and steam. The base or basic-acting salt &c.,. e.g. an alkali or alkaline earth metal hydroxide or oxide, or a carbonate, bicarbonate, borate, ammonium compound or organic compound, may be used in substantial excess of that necessary for the reaction. The separated, unreacted halohydrin may be returned continuously to the reaction zone. In an example the rectifying zone forms the upper, and the reaction and by-product withdrawal zones the lower part of a vertical glass tube used for the preparation of epichlorhydrin from a mixture of glycerol dichlorhydrins, using an aqueous lime slurry.