Azeotropic Distillation Process with Vertical Divided-Wall Column

Abstract

In order to separate a homogeneous binary azeotropic mixture, such as thanol and water, intoindividual components, an entrainer is usually added to form a new heterogeneous ternary azeotropicmixture. An azeotropic distillation method with the conventional two-column sequence is usually usedto complete the separation task.
In this paper, we present a new azeotropic distillation column with a vertical dividing wall,developed by improving the divided-wall column for ordinary three-component mixture separation asreported by Wright. The new system differs greatly from the conventional two-column sequence. In thissystem, the column is equipped with one condenser at the top and two reboilers at the bottom, allowingsingle-column azeotropic distillation. The features of this column are demonstrated by simulation forethanol dehydration using cyclohexane as entrainer in comparison with the conventional two-columnsystem. It is confirmed that for dehydration of a 90 wt% ethanol feed stock, an energy saving of about7% can be expected.