PURPOSE: To separate an organic compound in highly concentrated state or as a pure substance, by adding an electrolyte to an aqueous solution of an organic compound having azeotropic point under normal pressure, and contacting the solution with a high-density fluid of a state above or near the critical point.
CONSTITUTION: An aqueous solution of an organic compound having azeotropic point under normal pressure (e.g. alcohol, ketone, etc.) is added with an electrolyte (preferably lithium chloride) to a concentration of 0.5W5.0wt%, and the mixture is made to contact with a high-density fluid (preferably CO2) of a state above or near the critical point. The organic compound can be extracted by this process. When CO2 is used as the high-density fluid, the extraction is carried out preferably under 70W140atm at 20W50°C. The flow ratio of the high-density fluid to the aqueous solution of organic compound is preferably 13W20by weight. The objective compound can be separated from the high-density fluid system containing the organic compound extracted and concentrated in high concentration, by reducing the pressure and/or changing the temperature of the fluid system.
ARAI KUNIO
TAYAMA IKUTARO
MINAMINO YASUNOBU
