Verfahren zur Gewinnung von Glycid

1,183,360. Recovery of glycidol. HALCON INTERNATIONAL Inc. 20 July, 1967 [25 July, 1966], No. 33346/67. Heading C2C. Glycidol is recovered from a feed mixture comprising glycidol, allyl alcohol and higher boiling materials by conducting a first distillation of said feed mixture whereby a first overhead product and a first bottoms product are obtained, said first overhead product comprising allyl alcohol and said first bottoms product comprising glycidol substantially free from allyl alcohol, and conducting a second distillation, which is applied to the said first bottoms product, in the presence of a hydrocarbon azeotropic agent which forms a low boiling point azeotrope for the recovery, as a second overhead product, of a glycidol-azeotropic agent azeotrope. The glycidol azeotrope may be extracted with water to recover glycidol substantially free of the azeotropic agent in the form of a water solution of glycidol. Subsequently the water may be removed whereby substantially pure glycidol is obtained. The azeotropic agent is suitably a hydrocarbon and particularly useful are the aliphatic, naphthenic and aromatic hydrocarbons having the same skeletal carbon structure as the hydroperoxide employed in the epoxidation reaction wherein allyl alcohol is converted to glycidol. Those specified are ethylbenzene, cumene, benzene, toluene, pethyltoluene, isobutylbenzene, tetralin, diisopropylbenzene, xylenes, cyclohexane and alkylsubstituted cyclohexanes. In one embodiment, the distillation is conducted in the presence of a hydrocarbon azeotrope which forms a low-boiling azeotrope with glycidol, but which does not form an azeotrope with allyl alcohol, e.g. cumene, and in another embodiment the distillation is conducted in the presence of a hydrocarbon which forms two separate low boiling azeotropes, first with allyl alcohol and then with glycidol, e.g. ethylbenzene.