Environmental, economic and exergy analysis of separation of ternary azeotrope by variable pressure extractive distillation based on multi-objective optimization

• A novel variable pressure extractive distillation process with multi-objective optimization (NSGA-II) effectively separates the ternary azeotrope of tert-butyl alcohol/ethyl acetate/water. • Heat integration and heat pump assistance significantly reduce energy consumption and gas emissions, with the double heat pump scheme achieving a 55.83% reduction in gas emissions and 28.78% lower total annual cost. • The heat-integrated extractive distillation coupled with pervaporation achieves the highest exergy efficiency of 47.56%, demonstrating superior thermodynamic performance. • The study provides a feasible and sustainable approach for industrial separation of ternary azeotropes, balancing economic and environmental objectives.