Application of the SLV-EoS for representing phase equilibria of binary Lennard–Jones mixtures including solid phases

In 2003, Yokozeki proposed an equation of state capable of representing solid, liquid, and vapor phases. This equation represents an innovative approach of including solid in phase diagrams. The capability of this equation of state, named SLV-EoS, of giving a qualitative correct representation of phase diagrams for binary mixtures of Lennard–Jones spheres has been tested in this work. The SLV-EoS has been used for producing the phase diagrams of binary Lennard–Jones mixtures with diameter ratio σ11/σ22 ranging from 0.85 to 1, and well-depth ratio ɛ11/ɛ22 ranging from 0.625 to 1.6 at reduced pressure P*=Pσ113/ε11=0.002. The obtained phase diagrams have been compared with literature data obtained by Monte-Carlo simulation. The comparison shows the incapability of the SLV-EoS with null binary interaction parameters of predicting solid–liquid azeotrope and eutectic in the investigated range of σ11/σ22 and ɛ11/ɛ22. Binary interaction parameters have been regressed to allow the SLV-EoS giving a qualitative representation of the three types of phase diagrams: solid solution, solid azeotrope and simple eutectic. Binary interaction parameters are shown being smoothed functions of σ11/σ22 and ɛ11/ɛ22, allowing the prediction of the phase behavior for other Lennard–Jones mixtures or real mixtures of simple fluids.