Heat integration of distillation columns with thermal-coupling method for separation of ternary mixture

Despite distillation's popularity in the industry, it is highly energy-intensive. Heat integration is therefore essential considering the recent energy crisis. This paper presents thermal-coupling as an approach for separating the ternary mixture of n-pentane, n-hexane, and n-heptane. In this method, the first column supplies vapor to the second column while its reboiler is removed. The thermal-coupling method is evaluated using two classical arrangements. Simulation of separation processes is carried out using Aspen HYSYS, and distillation columns are simulated using the rigorous solving method rather than the shortcut method. It is concluded that thermal-coupling can reduce energy consumption by ۱۲.۵% and ۱۷.۴۳%, respectively, compared to the direct and indirect processes.

Keywords:

heat integration , distillation , direct , indirect , thermal-coupling