Abstract: The Soave[1]equation of state is extensively accepted because of its accuracy andsimplicity.In 1988,Tan et al.[2]suggested a modification by introducing atemperature-dependent factor to parameter"b"on the basis of statistical meaning,anda good accuracy was obtained for supercritical fluids as well as fluids approaching criti-cal conditions but not for mixtures.In the previous work,an extended Soave equa-tion of state[3]has been proposed to improve the prediction of liquid density.In thispaper,the extended equation is used to calculate vapor-liquid equilibria of mixtures atsubcritical conditions.

Key words: equation of state, vapor-liquid equilibria

摘要： The Soave[1]equation of state is extensively accepted because of its accuracy andsimplicity.In 1988,Tan et al.[2]suggested a modification by introducing atemperature-dependent factor to parameter"b"on the basis of statistical meaning,anda good accuracy was obtained for supercritical fluids as well as fluids approaching criti-cal conditions but not for mixtures.In the previous work,an extended Soave equa-tion of state[3]has been proposed to improve the prediction of liquid density.In thispaper,the extended equation is used to calculate vapor-liquid equilibria of mixtures atsubcritical conditions.

关键词: equation of state;vapor-liquid equilibria