Exploration of liquid-liquid equilibrium and interaction between guaiacol and water extracted by four ester solvents

Abstract

Four ester solvents were selected as extractants and compared to explore the separation process of recovering guaiacol from an aqueous solution. The liquid-liquid equilibrium (LLE) data for water + guaiacol+ {methyl acetate, ethyl acetate, n-propyl acetate or n-butyl acetate} were measured in 303.2 K and 101.3 kPa. The separate performance in the four extractants was compared and evaluated by the distribution coefficient (D) and the separation factor (S). The NRTL and UNIQUAC models were correlated and fitted to experimental data to obtain regression parameters. Furthermore, the hybrid surface analysis based on Gibbs energy topology verified that the binary interaction parameters are consistent with the measured data. The root mean square deviation (RMSD) of the NRTL and UNIQUAC model does not exceed 0.0076 and 0.0086, respectively, indicating that the above models are suitable for studying the correlation of the system. In addition, the interaction and interaction energy between component molecules were studied through the DMol3 module.