Heat integration of the separation process of minimum boiling azeotropic mixtures in order to reduce CO۲ emission and reduce utility consumption

Due to the azeotrope between Isopropyl alcohol and water, it is not possible to purify Isopropyl alcohol by normal distillation. In the present article, two processes of Pressure Swing Distillation (PSD) and Extractive Distillation (ED) are used to break azeotrope between Isopropyl alcohol and water. Via drawing a T-xy mixture diagram at different pressures, it is perceived that the azeotrope point of the mixture does not shift with pressure change. As a result, pressure swing distillation is not an appropriate choice for separating this mixture, but extractive distillation with DMSO solvent can bring isopropyl alcohol to ۹۹% purity. The problem is that the energy consumption of the extractive distillation process is high. That's why the feed-splitting method has been used in this article for the Heat integration of the process. To this end, the input feed to the first column was divided into two parts and about ۵۳% of it was preheated with the bottom product of the solvent recovery column. The upper part of the feed also enters the column without changing the temperature. The results reveal that the projected method can decrease the amount of both hot utility consumption and CO۲ emission by almost ۲۰%.

Keywords:

CO۲ emission , Heat integration , Azeotrope , Utility consumption