Abstract: Genetic algorithm was used to estimate the parameters of thermodynamic model of solution,and a modified genetic algorithm was proposed by modifying the strategy of mutation and the mode of competition.DMF+water+1-propanol VLE system was taken as an example,and the results were compared with those of PWELL method.It is found that the optimization ability of genetic algorithm is much more powerful than that of POWELL method not only in binary composition system but also trinary composition system.

Key words: Modified genetic algorithm, thermodynamic model of solution, parameter estimation