Liquid-Liquid Equilibrium, Solubility, and Critical States in an Acetic Acid-n-Butyl Alcohol-n-Butyl Acetate-Water System at 328.15 K and 101.3 kPa: Topology of Phase Diagrams and NRTL Modeling

Compositions of coexisting phases (liquid-liquid equilibrium), solubility, and critical states for the quaternary acetic acid-n-butyl alcohol-n-butyl acetate-water system were carried out at 328.15 K and 101.3 kPa. The results of the work include topological analysis of phase diagrams. The data on liquid phases were determined by gas chromatography analysis. Solubility results and critical compositions were obtained by a cloud-point technique method. Simulation was performed using a nonrandom two-liquid model. Calculated results are in sufficient agreement with experimental data. A comparative analysis of experimental, calculated, and literature data was carried out for binary, ternary, and quaternary mixtures. The location of the critical compositions at different temperatures in the concentration space is discussed. The corresponding phase diagrams are constructed in 2D and 3D concentration spaces. The features of each of the phase diagrams are discussed.

Automated summary

This study investigates the liquid-liquid equilibrium, solubility, and critical states of the quaternary system through gas chromatography and cloud-point technique. Topological analysis of phase diagrams was conducted, and simulation using a two-liquid model showed good agreement with experimental data. Comparative analysis with binary, ternary, and quaternary mixtures was carried out to discuss the location of critical compositions and construct phase diagrams in 2D and 3D concentration spaces. Features of each phase diagram were also discussed.