分馏,精馏
As the solution to be purified is heated, its vapors rise to the fractionating column. 当要被提纯的液体受热时,它的蒸汽上升到分馏柱。
Reaction is carried out under a fractionating column that allows aldehyde to pass but returns alcohol to the reaction vessel. 反应是在装有分馏柱的反应器中进行的,分馏柱能让醛通过但使醇回流到反应器中。