METHOD AND SYSTEM FOR SOLVENT RECOVERY, AND METHOD AND APPARATUS FOR FREEZE-DEHYDRATION

摘要

PROBLEM TO BE SOLVED: To recover a high-purity organic solvent with a water content lower than that of an azeotrope without adding or using a third component.

SOLUTION: A gas 1 containing an organic solvent is brought into contact with water in a gas absorbing column 20 to absorb the organic solvent with water. The obtained aqueous solution 2 of the organic solvent is distilled in a dehydration distillation column 30 so that the water content of the aqueous solution of the organic solvent is reduced to a water content equal to or higher than that of the azeotrope of the organic solvent and water. The obtained aqueous solution of the organic solvent is cooled in a freeze-dehydration apparatus 40 to separate the water contained in the solution by freezing. The water content of the organic solvent is thus reduced to a water content lower than that of the azeotrope of the organic solvent and water.

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