Process for the preparation of ethanol

A process for the preparation of ethanol by catalytic hydration of ethylene in a reaction section, in which process aqueous crude ethanol containing both higher- and lower-boiling impurities is obtained by condensing and scrubbing the gaseous reaction mixture and in a purifying section the aqueous crude ethanol is passed into a first distillation column, a top fraction containing the greater portion of the impurities is discharged from said column, the bottom product of the first distillation column is passed to a second distillation column, ethanol-water azeotrope is recovered as a side stream from the upper part of the second distillation column, one or more side streams containing high-boiling impurities are passed from a lower part of the second distillation column to a third distillation column, a top fraction containing lower-boiling impurities is removed from the third column, an ethanol-containing side stream is discharged from the upper part of the third column and one or more side streams containing higher-boiling impurities are removed from a lower part, characterized in that the top fraction of the first distillation column is wholly or partly hydrogenated at a pressure between 10 and 50 bar abs. and a temperature between 60.degree. C. and 140.degree. C., the hydrogenated product is fractionated in the third distillation column, and that the top fraction obtained by fractionation in the third column is recycled completely or partly into the reaction section.