Abstract: The present invention is a method for the separation of impurities from a crude ethanol aqueous solution, comprising of; (i) extracting lipophilic impurities within the crude ethanol aqueous solution into an extracting solvent phase by treating the crude ethanol aqueous solution with an extracting solvent comprising carbon dioxide in a liquid state or carbon dioxide in a super-critical state under conditions wherein a ratio of the weight of the extracting solvent to the weight of the crude ethanol aqueous solution is 2 or higher; and (ii) recovering ethanol entrained with the extracting solvent or ethanol and methanol entrained with the extracting solvent into an aqueous phase by contacting the extracting solvent phase resulting after extracting the impurities to with water in a countercurrent manner under pressures in a ratio of the weight of water to the weight of the extracting solvent of 0.3 or lower.

Abstract: A selectively water-permeable hydrolyzed membrane characterized in that it is mainly made of a material which can generate a carboxyl group by hydrolysis and that a part of the material is hydrolyzed to have carboxyl groups, which may be further coated with a hydrophilic polymer. The above membrane is useful as a selectively water-permeable membrane and is applicable not only to pervaporation and vapor permeation, but also to reverse osmosis, dehumidification of air and so on.