Comparison of SAFT-VR-Mie and CP-PC-SAFT in predicting phase behavior of associating systems III. Aliphatic hydrocarbons - 1-propanol, 1-butanol and 1-pentanol

This study compares the predictions of CP-PC-SAFT and SAFT-VR-Mie for binary systems of aliphatic hydrocarbons and the C3-C5 1-alkanols. Systems of carbon monoxide and hydrogen sulfide are considered as well. In all the cases zero values of the binary adjustable parameters have been implemented. Thanks to the superior flexibility achieved by fitting 6 pure compound parameters, SAFT-VR-Mie excellently represent various thermodynamic properties of the considered 1-alkanols. Since CP-PC-SAFT fits these data with only 2 adjustable parameters, its pertinent performance is less accurate, but remains reasonable good. At the same time, unlike SAFT-VR-Mie, CP-PC-SAFT rigorously obeys of the pure compound Tc and Pc, which allows accurate predictions of critical loci and VLE in the symmetric systems. Moreover, in exception of LLE in the systems of ethane and ethene, CP-PC-SAFT truthfully predicts critical data and the high pressure VLE in the asymmetric systems. SAFT-VR-Mie estimates these data in a less accurate manner, excepting the VLE of the C4-isomers and n-pentane systems. It the latter cases the results of both models are comparable. At the same time, SAFT-VR-Mie often yields more accurate results for the low-pressure VLE. Besides that, the predictions of CP-PC-SAFT for LLE in 1-alkanol – [C1MIM][NTF2] and – [C2MIM][NTF2] ionic liquid systems are presented. Despite the simplified approach to ILs, this model truthfully predicts the UCST data in 1-alkanol – [C1MIM][NTF2] and – [C2MIM][NTF2] systems, overestimating however the concentrations of ILs in both equilibria phases.