Process for the purifying distillation of crude sec-butyl alcohol

A process for the continuous purifying distillation of crude sec-butyl alcohol obtained by catalytic hydration of n-butenes at elevated temperature and elevated pressure and by separation of unreacted olefin from the reaction product, wherein the crude sec-butyl alcohol containing di-sec-butyl ether and tertiary butyl alcohol together with higher and lower boiling components is introduced to the upper part of a distillation column, the energy required for distillation is supplied at the bottom of the column, azeotropes formed in the presence of water are distilled of overhead, and dry sec-butyl alcohol is withdrawn at the bottom of the column, said process comprising:

• (a) feeding at the top of the column the amount of water required for forming the azeotropes;
• (b) supplying sufficient energy to the base of the column to maintain a temperature between 87.5.degree. C. and 99.5.degree. C. at a temperature control point in the middle of the column,
• (c) feeding the crude sec-butyl alcohol to the distillation column at a point below the top of the column and above the temperature control point;
• (d) condensing the azeotropes and lower boiling components distilled overhead forming a water rich phase and an alcohol and ether rich phase and returning as reflux to the top of the column the water rich phase and a sufficient amount of the alcohol and ether rich phase to maintain the desired reflux ratio for distillation of all of the azeotropes;
• and
• (e) withdrawing part of said alcohol and ether rich phase as the top product from the distillation.