Abstract: Disclosed is a purification process for removing lipophilic impurities coined in an aqueous crude ethanol solution, in particular, for efficiently removing impurities consisting of C.sub.3 -C.sub.4 alcohols. The process involves (a) a first extraction step wherein the aqueous crude ethanol solution is extracted with an extractant for removing the lipophilic impurities, except for the C.sub.3 -C.sub.4 alcohols, contained in the aqueous crude ethanol solution by subjecting the aqueous crude ethanol solution to extraction with the extractant in a pressurized state containing carbon dioxide in a liquidized state or carbon dioxide gas in a supercritical state; (b) a concentration-distillation step wherein a raffinate obtained in the first extraction step is fed to a distilling column to thereby obtain a highly concentrated aqueous ethanol solution from a top of the distilling column and withdraw fraction containing C.sub.3 -C.sub.
Type:
Grant
Filed:
February 3, 1993
Date of Patent:
February 8, 1994
Assignee:
Basic Industries Bureau of Ministry of International Trade and Industry