Method for continuously producing a cyclic formal

摘要

Cyclic formal is manufactured by cyclic reaction of an alkylene glycol and an aldehyde in a reactor, producing formal mixed with unreacted aldehyde as an impurity, which impurity is reduced in amount by connecting the reactor to a distillation tower and continuously supplying alkylene glycol to the distillation tower from which unreacted formaldehyde and a cyclic formal are being distilled, and continuously reacting them with supplied raw formaldehyde by countercurrent flow during distillation; water content in azeotropic admixture with cyclic formal can be removed by azeotropic distillation with a hydrocarbon azeotropic mixture with water, distilling water from the cyclic formal.