Abstract: Here we review a new class of mixing rules that have extended range of mixtures and condi-tions that can now be described by equation of state models.One characteristic of these mixing rulesis that they simultaneously satisfy the boundary conditions of producing a second virial coefficientthat is quadratic in mole fraction,and a free energy of mixing like that of an activity coefficientmodel at high density,though the mixing rule is itself independent of density.We show that usingthis mixing rule,various asymmetric,highly nonideal mixtures can be accurately described.Oneserendipitous result is that the parameters in this mixing rule model are almost independent oftemperature,which allows accurate extrapolations of phase behavior to be made over large ranges oftemperature and pressure.

Key words: equations of state, mixing rules, phase equilibrium, complex mixtures

摘要： Here we review a new class of mixing rules that have extended range of mixtures and condi-tions that can now be described by equation of state models.One characteristic of these mixing rulesis that they simultaneously satisfy the boundary conditions of producing a second virial coefficientthat is quadratic in mole fraction,and a free energy of mixing like that of an activity coefficientmodel at high density,though the mixing rule is itself independent of density.We show that usingthis mixing rule,various asymmetric,highly nonideal mixtures can be accurately described.Oneserendipitous result is that the parameters in this mixing rule model are almost independent oftemperature,which allows accurate extrapolations of phase behavior to be made over large ranges oftemperature and pressure.

关键词: equations of state;mixing rules;phase equilibrium;complex mixtures