Determination and correlation of liquid-liquid equilibrium data for extraction and separation of methacrylic acid aqueous solution
This study focused on the challenge in separating methacrylic acid(MAA)from water(H2O)due to their formation of an azeotropic mixture.The research encompassed the selection of extractants for MAA aqueous solution purification,and the determination and correlation of ternary liquid-liquid equilibrium data for MAA-H2O-extractant system.Four extractants,namely toluene,n-hexane,cyclohexane,and dibutyl phthalate(DBP),were investigated for their extraction efficiency.DBP was determined as the optimal extractant with superior comprehensive performance.Under atmospheric pressure,liquid-liquid equilibrium data for the H2O-MAA-DBP ternary system at 20 ℃,30 ℃,and 40 ℃ were measured.The experimental results validated the consistency of the phase equilibrium data with Hand equation and Othmer-Tobias equation,demonstrating a linear correlation coefficient(R2)exceeding 0.99.The UNIQUAC model was used to fit the experimental data and obtain binary interaction parameters for the three components.The root-mean-square-deviation between the model predictions and experimental values was below 0.07,indicating high accuracy of the experimental data and fitting parameters.This provided a basis for the application of DBP in the industrial purification of MAA aqueous solutions.