(427e) Separation Effects of Ethyl Lactate on Vapor-Liquid Equilibria of Acetone + Methanol Azeotropic System Using an Automatic Apparatus

Alternative solvents for green chemistry have been paid a great deal of attention as promising candidates to replace toxic organic solvents and volatile organic compounds (VOCs). One type of alternative solvents, renewable solvents, can be easily produced from biomass feedstocks. One such renewable solvent, ethyl lactate, has excellent properties, such as low toxicity, relatively high boiling point, high solvency power, good biodegradability and recyclability [1-3].

This work aims for a use of ethyl lactate as green solvent for separation and purification processes, which VOCs have been used as entrainer for azeotropic or extractive distillation. Previously, we investigated ethyl lactate as entrainer for the separation of binary azeotropic systems using extractive distillation by measuring the isobaric vapor-liquid equilibria (VLE) [4, 5]. In this work, we selected acetone + methanol binary azeotropic system, which forms a minimum boiling point azeotrope. isobaric VLE data of three binary constituent systems, i.e., acetone + methanol, acetone + ethyl lactate, and methanol + ethyl lactate were measured at 53.3 to 101.3 kPa by an automatic apparatus for VLE measurements developed in our laboratory [6]. The experimental results of VLE were represented by the non-random two-liquid (NRTL) model. The separation effects of ethyl lactate as entrainer for the separation of acetone + methanol were evaluated by calculating residue curve map and α₁₂using the NRTL model coupled with binary parameters obtained from binary VLE data. Minimum liquid composition of ethyl lactate for breaking the azeotropic point of the system was compared with those of entrainer candidates studied in the reported works.

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