Exploration of extracting ethyl lactate from aqueous solution using alkyl alcohols: Combination of experiment and mechanism analysis

For separating ethyl lactate from an aqueous solution, alkyl alcohols were selected as extractive solvents for experimental exploration and mechanism analysis. The liquid–liquid equilibrium data of {water + ethyl lactate + alkyl alcohols (1-pentanol, 1-heptanol, 1-octanol, and 1-nonanol)} were measured in 303.2 K and 101.3 kPa, and the distribution coefficient and separation factor of each system were calculated to evaluate the extraction effect. Meanwhile, the NRTL and UNIQUAC models were correlated with experimental data, and the model parameters were regressed. The UNIFAC model was used to predict the LLE data. The regression model parameters were checked using the GMcal_TieLinesLL tool, and the results meet the Gibbs stability criteria. The separation mechanism was explored by analyzing σ-profile, deformation charge density, interaction energy, and RDG analysis.