Heat-Integrated Azeotropic Distillation and Extractive Distillation for the Separation of Heterogeneous Ternary Azeotropes of Diisopropyl Ether/Isopropyl Alcohol/Water

The formation of heterogeneous ternary azeotropes poses a serious challenge to the recovery of diisopropyl ether (DIPE) and isopropyl alcohol (IPA) from the industrial effluent. To reduce the energy consumption rates and improve the process efficiency of this energy-intensive separation process, three novel intensified separation configurations with pressure-swing heat integration are proposed, which include one improved extractive distillation (ED) strategy and two heterogeneous azeotropic distillation (HAD1 and HAD2) schemes. A comprehensive evaluation of the three separation schemes is performed in terms of economics and CO2 emissions. The heat-integrated configurations, respectively, reduce the 29.78, 42.19, and 39.71% in energy consumption rates. In addition, the heat-integrated HAD2 scheme demonstrates the greatest energy-saving potential, wherein the total annual cost is reduced by 1.61 and 7.37% compared to the ED and HAD1 schemes, respectively. In general, these efforts provide a reference for recycling DIPE and IPA from the industrial effluent.