| 摘要 |
<p>When obtaining a target substance by gradually cooling the reaction liquid by cooling in a plurality of stages divided in series, and then distilling the cooled reaction liquid by distillation in a plurality of stages divided in series, this method and this apparatus include: circulating a heating medium to be used for cooling in the plurality of the stages by way of; sequentially passing the heating medium toward the most upstream cooling stage from the most downstream cooling stage of the reaction liquid; cooling the heating medium which has been discharged from the most upstream cooling stage by using the heating medium for keeping or raising the temperature of the liquid which has been discharged from the distillation in the plurality of the stages; and returning the cooled heating medium back to the most downstream cooling stage of the reaction liquid.</p> |
