Azeotropic distillation process for methanol-ethyl acetate-water separation: design and control

Abstract

This study proposes the synthesis, design, and control of a separation process for a concentrated ternary mixture of methanol, ethyl acetate, and water, which exhibits two minimum boiling azeotropes, to separate it into constituent nearly pure components. The proposed flowsheet leverages the presence of a liquid-liquid envelope by using a liquid-liquid extractor with recycled water as a solvent to strategically bring the initial feed point into the liquid-liquid split region, facilitating energy-efficient separation. The design consists of a liquid-liquid extractor followed by a triple-column distillation sequence. Compared to the existing extractive heterogeneous azeotropic distillation process, the proposed process achieves savings of 36.9% in total annualized cost, 46.1% in reduced energy consumption, and CO₂ emission. Additionally, a regulatory plant-wide decentralized control structure has been developed through rigorous dynamic simulations, demonstrating its effectiveness in rejecting principal disturbances in throughput and feed composition.

Graphical abstract

Keywords

azeotropic distillation / liquid-liquid extractor / plantwide control / economic design

RIGHTS & PERMISSIONS

Higher Education Press