Process for preparing alkanediol and dialkyl carbonate

A process for the preparation of an alkanediol and a dialkyl carbonate comprising:

• (a) reacting an alkylene carbonate and an alkanol in the presence of a transesterification catalyst to obtain a reaction mixture comprising dialkyl carbonate, unconverted alkanol, alkanediol and unconverted alkylene carbonate;
• (b) subjecting the reaction mixture to distillation in a first distillation column to obtain a top stream comprising dialkyl carbonate and alkanol and a bottom stream comprising dialkyl carbonate, alkanol, alkanediol and alkylene carbonate;
• (c) subjecting the bottom stream from the first distillation column to distillation in a second distillation column to obtain a top stream comprising dialkyl carbonate and alkanol and a bottom stream comprising alkanediol and alkylene carbonate;
• (d) recovering alkanediol from the bottom stream from the second distillation column;
• and
• (e) subjecting the top streams from the first and second distillation columns to distillation in a third distillation column to obtain a top stream comprising alkanol and a bottom stream comprising dialkyl carbonate.