Integrated ionic liquid and process design involving azeotropic separation processes

Abstract

In process industries, separation techniques need to be employed to match product quality and purity specifications. Most vapour-liquid based separation techniques involving the separation of close-boiling or azeotropic as well as gaseous mixtures are energy intensive. Downstream separations from bioreactors are, on the other hand, difficult because of relatively small amounts of products in large amounts of reactants and carriers such as water. With growing energy and environmental challenges, novel, sustainable and innovative separation techniques are receiving increasing attention. Because of their non-volatility and other tuneable properties, ionic liquids (ILs) based separation techniques are promising alternatives. In this work, a systematic method that combines group contribution (GC)-based property prediction and IL-based separation process design is presented. That is, the optimal IL molecular structure and the corresponding optimal flowsheet configuration for a specific IL-based separation process are simultaneously identified. Case studies involving the separation of azeotropic mixtures such as ethanol-water and acetone-methanol are presented to highlight the application of the method for synthesis-design of the IL-based separation technology.