Application of CP-PC-SAFT and PC-SAFT for simultaneous prediction of LLE and high-pressure VLE with universal k₁₂ values. III. Systems of naphthenic compounds

This study compares overall robustness and reliability of PC-SAFT and CP-PC-SAFT in predicting the available data on thermodynamic properties of cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane, and trans-decalin along with VLE, LLE, LLVE and critical loci in 36 binary systems of these compounds with pyrrole, γ-valerolactone, sulfolane, aniline, N-methyl-2-pyrrolidone, methane, argon, carbon monoxide, nitrogen, ethene, ethane, propane, chlorodifluoromethane and hydrogen sulfide. LLE in 4 ternary systems of cyclohexane, benzene, toluene, ethylbenzene, 1,2-dichloroethane and sulfolane are also considered. The PC-SAFT molecular parameters of Ramírez-Vélez et al., AIChE J. 2022, 68, e17722 were adopted. Both models were applied without considering polarity and self-association. The same universal value of k₁₂ = 0.041 was used for all the systems. This value was obtained at the UCST of an arbitrary selected cyclohexane–pyrrole system. It is demonstrated that some data, such as the compositions of vapor phases at atmospheric pressure and most high-pressure VLE above 400 K are more accurately predicted by PC-SAFT. However, CP-PC-SAFT outperforms it in the cases of other data, namely the UCSTs, the tie lines slopes in the ternary systems, the LL critical loci of the methane systems at ∼200–1200 bar, most VLE in the systems of nitrogen, LLE and VLE in the systems of trans-decalin. Ultimately, it can be concluded that both approaches demonstrate fairly good overall accuracy. Thus, they can be used to pre-evaluate unavailable phase equilibria data over a wide range of temperatures and pressures in systems containing not just the considered compounds, but also their analogues.