APPARATUS FOR PURIFYING ETHANOL

PURPOSE:To recover efficiently heat and promote energy saving, by exchanging heat of an ethanol-containing vapor discharged from the top of a column, e.g. concentration column, rectifying column or purifying column, intermittently with water under reduced pressure, and recovering the heat of the generated steam under reduced pressure. CONSTITUTION:An ethanol-containing vapor discharged from the top of a column, e.g. concentration column (A2'), rectifying column (B'), purifying column (C') and impurity treating column (G'), is introduced into condensers 21-24, and water in a water supply tank 42 decompressed under reduced pressure by a vacuum pump 61 is fed to the condensers 21-24 by a pump 63 to exchange heat intermittently with the ethanol-containing vapor. The generated steam under reduced pressure is then passed through a gas-liquid separation tank 41 and fed to a heat pump (Class II) 51 for generating vapor, and heat is recovered in an absorber (51d) to generate steam, which is passed through a gas-liquid separation tank 43 and a steam supply tank 44 to each distillation column for use as a heat source.