A solid solution modeling approach somehow analogous to the EoS approach for fluids: Application to equilibria involving fluid phases and solid solutions

Abstract

In the present work, a modeling approach applicable over wide ranges of temperature and pressure to the representation of the thermodynamic properties of pure components in solid state is extended to the case of solid solutions. The resulting Solid Solution (SS) modeling Approach (SSA) makes possible to avoid, for multicomponent systems, the inconsistent assumption of solid precipitation in pure state. The SSA here proposed accounts in a straightforward way for the effects of temperature, pressure and SS composition on the thermodynamic properties of the SS. Modeling results are shown for the binary systems Ar(argon)+CH4(methane) and CH4 + n-C20H42 (n-eicosane) in wide ranges of conditions. The agreement between the calculation results obtained for the particular form of the SSA tested in this work and the experimental phase equilibrium data is good for the systems studied. The results in this work indicate that the proposed SSA is able to properly capture the patterns of the phase behavior of the studied mixtures.