RECOVERY OF SOLVENT FROM DILUTE AQUEOUS SOLUTION OF SOLVENT

PURPOSE:To stably operate an extracting tower and the succeeding distillation tower by carrying out extracting operation by supplying a part of an extracting agent to a feed liquid supply line of the extracting tower to prevent the clogging of the automatic control apparatus of the raw liquid due to a low molecular polymer. CONSTITUTION:To a feed liquid supply line 2 connected to the upper part of an extracting tower 1, a flow detecting end 7 and a flow control valve 8 are provided and, to an extracting agent supply line 3 provided to the lower part of the extracting tower 1, a branched pipe 6 is provided to continuously supply a part of an extracting agent to the feed liquid supply line 2. When a dilute acetic acid aqueous solution is used as the feed liquid and ethyl acetate is used as the extracting agent to carry out extraction, ethyl acetate containing acetic acid extracted therefrom is taken out from the line 10 of a tower top. This mixed liquid is sent to a distillation tower 11 and acetic acid is recovered from an acetic acid recovering line 12 and ethyl acetate is recovered from an ethyl acetate recovering line 13. In this case, when ethyl acetate is supplied to the raw liquid in a range of about 0.5-20wt,% in the extracting tower 1, a polymer is not adhered to an automatic flow control apparatus.