SEPARATION PURIFICATION METHOD OF ALCOHOL-CONTAINING REACTION LIQUID

摘要

PURPOSE:To easily recover high concn. ethanol with low energy by introducing the light fraction obtained from the top part of a distillation tower for separation of reaction product to a distillation tower for separation of alcohol and to a gas separation membrane module so as to effect separation and purification. CONSTITUTION:The light fraction (2) essentially containing lower alcohol and water is introduced to the upper half of distillation tower 2 for recoverying alcohol and distilled therein. A liquid substantially comprising water (3) is drained from the bottom of the distillation tower 2, while the vapor discharged from the top of the distillation tower 2 is cooled by a vapor-liquid separation type cooler 21. Part of the vapor essentially comprising lower alcohol (4) is introduced from the upper part of the cooler 21 to a gas separation membrane module 3 in the next state having a gas separation membrane which selectively transmits water. The untransmitted vapor (6) comprising high concn. lower alcohol is taken out from the untransmitting side of the gas separation membrane, liquefied by a cooler 33 and recovered in an alcohol tank 5.