Liquid–Liquid Equilibrium for Ternary Systems of Water, Methacrylic Acid, and Alkyl Alcohols: Thermodynamic Analysis and Solvent Comparison

Abstract

The development and research of biomass fuels have been paid more and more attention. The production of methacrylic acid is accompanied by a large amount of water and environmental pollution. Therefore, the separation of methacrylic acid from aqueous solution is of great significance for industrial production and environmental protection. The liquid−liquid equilibrium (LLE) for ternary systems of water + methacrylic acid + alcohol solvents at 303.2 K and 101.3 kPa was investigated. Thermodynamic models (NRTL and UNIQUAC) were used to correlate and regress the experimental data. The root-mean-square deviation (RMSD %) was used to evaluate the deviation between the experimental value and the calculated value, which were 1 and 1, respectively, indicating that the extractants selected in the experiment could well separate methacrylic acid from the aqueous solution, and 1-octanol exhibits better extraction performance. The correlation of LLE data is proven by MATLAB. In addition, the binary interactive parameters of the model regression are verified by MATLAB.