Experimental determination of the critical loci for {n-C6H14 or CO2 + alkan-1-ol} mixtures. Evaluation of their critical and subcritical behavior using PC-SAFT EoS

Vapor–liquid critical locus (x, Tc, Pc) has been determined, in the whole range of mole fractions, for the systems {n-hexane + methanol, or +ethanol, or +propan-1-ol, or +butan-1-ol} and {CO2 + methanol, or +ethanol, or +propan-1-ol, or +butan-1-ol}.A comprehensive bibliographic review for the vapor–liquid equilibrium (VLE) and the critical locus of these systems has been performed, and they have been modelled with PC-SAFT EoS. The three parameters that characterize the segments of pure compounds have been rescaled from their critical point values. In all cases, the classical mixing rules and temperature-dependent binary interaction parameters kij(T)=kij0+kij1T have been used.The average deviations obtained for the n-hexane + alkan-1-ol binary mixtures are: for critical loci, mean relative deviation in critical temperature MRD(Tc) = 0.47% and in critical pressure MRD(Pc) = 3.38%; for VLE, mean relative deviation in bubble pressure MRD(P) = 2.90% and absolute deviation for the solvent mole fraction in the vapor phase ΔyC6H14=0.031.The average deviations obtained for the CO2 + alkan-1-ol binary mixtures are MRD(Tc) = 1.91% and MRD(Pc) = 5.93%; MRD(P) = 7.07% and ΔyCO2=0.022.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Vapor–liquid critical locus has been determined for {n-C6H14 or CO2 + alkan-1-ol} mixtures. ► A comprehensive bibliographic review for the VLE and critical locus of these systems has been performed. ► These systems have been modeled with PC-SAFT EoS.