Process for producing anhydrous ethanol

摘要

A process for producing anhydrous ethanol, using an apparatus comprising a combination of a concentration column, an azeotropic distillation column and a solvent recovery column, and capable of effectively utilizing the vapor at the tops of the concentration column and the azeotropic distillation column, is provided, which process comprises: (i) connecting an absorption type heat pump functioning as a condenser and a reboiler at the same time, to either one of the concentration column or the azeotropic distillation column; (ii) connecting a combination of a mechanical type heat pump with a heat exchanger functioning as a condenser and a reboiler at the same time to another of the columns; (iii) using a back pressure turbine as a machine for driving the mechanical type heat pump; and (iv) using the back pressure steam generated by operating the mechanical type heat pump as the heat source for the absorption type heat pump.