Design and Multiobjective Optimization of a Novel Double Extractive Dividing Wall Column with a Side Reboiler Scheme for the Recovery of Ethyl Acetate and Methanol from Wastewater

This work presents the development of two novel intensified energy-efficient extractive distillation configurations for the separation of ethyl acetate and methanol from waste effluent while prioritizing economic, environmental, and safety performances. Departing from the typical three or four column extractive distillation process, we proposed two intensified processes that offer superior performance. Specifically, we introduced the extractive dividing wall column with a side reboiler (EDWC-SR), which combines the four columns into two, and the double EDWC-SR (DEDWC-SR), which combines the four columns into a single unit. Subsequently, multiobjective optimization and multicriteria decision making were used to obtain the optimum configurations for the three processes, i.e., base case, EDWC-SR, and DEDWC-SR. Both the EDWC-SR and DEDWC-SR gave better economic and environmental performances relative to the base case with slightly lowered safety performance. The DEDWC-SR gave the lowest total annual cost and CO₂ emission by 20.20 and 33.81%, respectively, and a higher safety index by 18%, relative to the base case.