Economic, environmental, exergy (3E) evaluations of recovering n-propyl acetate and n-propanol from wastewater via distillation coupled pervaporation

Abstract

This work investigates an efficient and sustainable process for recovering n-propyl acetate and n-propanol from wastewater via extractive distillation coupled with pervaporation (PV). The selection of potential extractants is based on the equilibrium data between the system and the extractants in vapor-liquid phase. For the ternary extractive distillation process, we optimize it using the Non-Dominated Sorting Genetic Algorithm II with the objectives of minimizing the total annual cost and gas emissions. The PV model is integrated with the distillation process to enhance solvent recovery, while an energy-efficient scheme combined with heat integration technology and heat pump improves separation efficiency. Economic, environmental and exergy analyses are conducted to evaluate feasibility, revealing that coupling extractive distillation with PV enhances economic and environmental benefits compared to basic processes. The combination of heat pump assisted heat integration technology further improves the economy performance, environmental protection and thermodynamic efficiency, and the process selection needs to be balanced according to the actual industry.