Method for separating and concentrating an organic component from an aqueous solution containing same

Disclosed is a method for separating and concentrating an organic component having a lower boiling point than water from an aqueous solution containing the organic component which comprises the steps of (1) bringing an aqueous solution containing an organic component having a lower boiling point than water into contact with one surface of a hydrophobic porous membrane, continuously or intermittently evacuating the side of the porous membrane opposite to the aqueous solution to obtain a concentrated vapor of the organic component, and liquefying the vapor; and (2) bringing the resulting concentrated aqueous solution into contact with one surface of a hydrophobic nonporous membrane, evacuating the side of the nonporous membrane opposite to the concentrated aqueous solution to obtain a further concentrated vapor of the organic component, and liquefying the vapor. When this method is applied, for example, to a continuous fermentation process, the fermentation can be continued with efficient removal of the fermentation product from the broth.