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.