Extractive distillation of ethyl acetate-ethanol-water ternary system using deep eutectic solvent (DES): A techno economic and energy assessment

The extractive distillation (ED) process has been established as a commercially viable process that can be used to break the azeotropic systems. The present study investigates the performance and feasibility of conventional solvent (glycerol) and choline chloride-glycerol based deep eutectic solvent (DES) as entrainers for the separation of ethyl acetate-ethanol-water ternary mixture through ED. A comprehensive approach is proposed with phase-equilibrium measurements and process simulation through Aspen Plus for different entrainer to feed ratio (E/F). Optimization of the process is based on performance indicators such as Total Annual Cost, CO2 emissions, and Specific Energy Consumption. A sequential iterative algorithm was used to find the optimum E/F in distillation trains. The performance analysis has shown a reduction of 45.89% in global TAC with DES as an entrainer. The combined entrainer requirement for the dehydration was 268.3 kmol/h and 118.86 kmol/h with glycerol and DES respectively. The process sees a 58.21% total energy saving with a 15% and 44.5% reduction in Specific Energy Consumption and CO2 emissions respectively as compared to glycerol as an entrainer. The study provides a comparison and proves that DES is an effective entrainer to break the azeotropic point as a low-cost and eco-friendly alternative to conventional solvents.