Using those which are chosen from n Hexan, cyclohexane, these constitutional isomers and the group which consists of the blend above those 2 genera,

摘要

PROBLEM TO BE SOLVED: To provide a method for azeotropic distillation capable of efficiently removing the impurities of e.g. toluene and automatically controlling an azeotrope-distilling column by subjecting a mixed solution of methyl ethyl ketone, glycol ether and water to azeotropic distillation in the presence of an entrainer. ;SOLUTION: This azeotropic distillation of a mixed solution of methyl ethyl ketone, glycol ether and water is conducted in the presence of an entrainer of e.g. n-hexane, cyclohexane, a structural isomer thereof or a mixture of 2≥ kinds of these components. This is pref. carried out by controlling (i) an amount of circulation of the entrainer to a decanter and furthermore (ii) an amount of heat added to a reboiler according to a water component detected in the mixed solution.;COPYRIGHT: (C)2000,JPO