Towards sustainable separation of the ternary azeotropic mixture based on the intensified reactive-extractive distillation configurations and multi-objective particle swarm optimization

Abstract

The separation of ternary azeotropic systems has received significant interest as it enables the recovery of value-added organic solvents, subsequently contribute towards environmental protection. In this work, we propose a novel approach that involves the conceptual design, multi-objective optimization, and process evaluations for developing two different processes, i.e., double-column reactive-extractive distillation (DCRED) and reactive-extractive dividing wall column (REDWC), for the separation of ethanol/tert-butanol/water ternary azeotropic mixture. The conceptual design of the proposed processes was conducted using kinetic and thermodynamic analysis while optimal operating conditions of the established processes were obtained via multi-objective particle swarm optimization algorithm. Then, both developed processes were evaluated based on the total annual cost (TAC), CO2 emissions, and thermodynamic efficiency. From the steady-state simulation, DCRED and REDWC provides a TAC of 1.056 × 106 US$ and 1.117 × 106 US$, respectively. Likewise, it provides CO2 emissions of 731.27 kg/h and 733.42 kg/h, respectively. The energy efficiency of the DCRED and REDWC were found to be 1.285% and 1.055%, respectively. Relative to the conventional extractive distillation process, the TAC and CO2 emission for the proposed DCRED reduced significantly by 55.4% and 61.8%, respectively. Similar reduction was also observed for the REDWC which provides 52.8% and 61.7% lower TAC and CO2 with respect to the conventional process. In addition, the thermodynamic efficiency of the developed DCRED and REDWC processes are improved by 40.4% and 15.3% in comparison to the conventional extractive distillation scheme.