Application of Genetic Algorithm to the Calculation of Interaction Parameters of Activity Coefficient Models in Liquid-Liquid Extraction

Recently, optimization methods have been extensively applied in phase equilibrium calculations. Among these methods, Genetic Algorithm (GA) can be used to calculate the interaction parameters of activity coefficient models in equilibrium systems. In this study, based on the genetic algorithm, the interaction parameters of 5 activity coefficient models (2-suffix Margules, 3-suffix Margules, Wilson, NRTL and UNIQUAC) have been calculated for 20 ternary extraction systems (water + carboxylic acids + organic solvents) including 126tie-lines. The values of binary interaction parameters of these models along with the root mean square deviations (RMSD) are reported. The mean values of RMSD of the systems in the order of the mentioned models have been calculated 0.0298, 0.0067, 0.0114, 0.0025 and 0.0052, respectively. The results show that all models except 2-suffix Margules model have relatively good accuracy. By comparing the RMSD values in literature and the values determined by GA for NRTL and UNIQUAC models, the RMSD values of the models improved from 0.0124 and 0.0181 to 0.0025 and 0.0052, respectively