To provide a method for removing water from a reaction mixture by using a membrane of cellulose diacetate, etc.
In removing water from a reaction mixture of an aqueous solution of an acid, an acid anhydride or an alkali metal hydroxide and an alcohol by using vapor permeation/super-evaporation method, firstly an edduct having the lowest boiling point in an amount equal to or smaller than stoichiometry of another specific edduct together with the specific adduct as the reaction mixture are added, the reaction mixture is heated to a boiling point, a vapor mixture comprising produced from the boiling reaction mixture and consisting essentially of water and the edduct having the lowest boiling point is fed to a membrane, the vapor mixture from which water is removed is recycled to the reaction mixture and the edduct having the lowest boiling point is supplied to the reaction mixture.
WINKLER ADOLF DIPL CHEM DR
BREMEN JOSEF DIPL CHEM DR
