Process for removing 2-butanol from tert.-butanol/water mixtures

摘要

2-Butanol is separated from an industrial mixture by separating water from the industrial mixture by distillation to obtain a distillate having a proportion by mass of water is greater than the limit concentration of the distillation boundary line connecting an azeotrope of tert-butanol and water, and an azeotrope of 2-butanol and water. Separating 2-butanol (SBA) from an industrial mixture which comprises SBA, tert-butanol (TBA) and water where the proportion by mass of water is greater than the limit concentration of the distillation boundary line connecting an azeotrope of TBA and water and an azeotrope of SBA and water, involves: (a) separating water from the industrial mixture by distillation to obtain a distillate, where the distillate has, in terms of the SBA, TBA and water in the industrial mixture, a proportion by mass of water, which at a pressure, is greater than the limit concentration of the distillation boundary line connecting an azeotrope of TBA and water, and an azeotrope of SBA and water; (b) subsequently changing the pressure so that the mixture has, in terms of the SBA, TBA and water in the distillate, a proportion by mass of water which is less than the limit concentration of the distillation boundary line connecting the distillation boundary line connecting an azeotrope of TBA and water, and an azeotrope of SBA and water; and (c) subsequently distilling the mixture at the same pressure into a stream comprising SBA and a stream comprising TBA and water. An independent claim is also included for SBA prepared by the inventive process.