To provide a manufacturing method of a dialkyl carbonate and a diol using a cyclic carbonate and an aliphatic monohydric alcohol, which maintains a high reaction rate, prevents deterioration in catalyst activities without requiring complicated apparatuses or operations and retains stable reaction results over a long period of time.
In the manufacturing method comprising drawing out a mixture containing the dialkyl carbonate from the upper part of a continuous multistage distillation column A, drawing out a mixture containing the diol from the lower part of the continuous multistage distillation column A, feeding the mixture containing the diol to another distillation column B and returning at least a part of compounds having a lower boiling point than the diol to the continuous multistage distillation column A, the water concentration in the mixture of the compounds having a lower boiling point than the diol returned to the continuous multistage distillation column A is caused to be at least 1 ppm and at most 1,000 ppm. Thus, the life of an alkali metal compound and/or alkaline earth metal compound catalyst is prolonged.
TOJO MASAHIRO
YATANI HIROSHI
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