Optimal design of the ternary azeotrope separation process assisted by reactive-extractive distillation for ethyl acetate/isopropanol/water

Abstract

There are numerous issues with the separation process for ternary systems containing multi-azeotropes. Specially, for the aqueous azeotrope as ethyl acetate-isopropanol-water, the presence of water results in a ternary azeotrope, three binary azeotropes and a heterogeneous region. Reactive distillation is introduced to break the azeotropes and simplify complexity by consuming water through ethylene oxide hydration reaction. The triple-column extractive distillation process (TED) and two enhanced processes combined with reactive distillation (i.e., double-column reactive-extractive distillation process (DRED) and reactive-extractive dividing-wall column process (REDWC)) are designed for the separation in this work. A simultaneous optimization strategy is proposed to optimize the parameters through the Particle Swarm Optimization algorithm taking the total annual cost (TAC) as the optimization objective. Then, the CO2 emissions and thermodynamic efficiency are calculated to assess these three processes. Exergy analysis and entropy production are applied to quantify each component to the total irreversibility. Results show that reactive-extractive distillation effectively realize lower TACs with better environmental performance. The TACs of DRED and REDWC processes are reduced by 39.04% and 46.01% compared with TED process, respectively. The thermodynamic efficiency of DRED and REDWC processes increased from 5.40% to 42.88% and 43.64%, respectively.