CONCENTRATION AND RECOVERY OF FERMENTATION ALCOHOL

摘要

PURPOSE:To enable the concentration and recovery of alcohol saving the energy consumption, by evaporating a fermentation liquid to obtain an aqueous solution having a specific alcohol concentration and extracting the solution in the presence of an extractant under high pressure. CONSTITUTION:A fermentation liquid is transferred from a fermentation tank 1 filled with immobilized microorganisms (e.g. Saccharomyces cerevisiae) through a line 4 to an evaporator 6 and the vapor heated and evaporated in the evaporator 6 is sent through a line 7 to a condenser 12 and condensed to obtain an aqueous solution of alcohol having an alcohol concentration of 15-40wt%. The concentrated solution is pressurized with a pump 15 of a line 21 and supplied to the top of a high-pressure extraction column 22. An extractant (e.g. carbon dioxide) is introduced into the extraction column through a line 28 to effect the extraction of ethanol. The objective concentrated liquid having an alcohol concentration of preferably 85-95wt% is obtained from a line 26.