Critical, supercritical and phase-transition properties of binary 1-propanol + n-heptane mixtures

Abstract

PρTx relationship of four binary 1-propanol + n-heptane mixtures was measured using high-temperature and high-pressure constant-volume piezometer technique in the critical, supercritical, and in the immediate vicinity of the liquid–gas phase transition curve. The experimental temperature and pressure ranges were from (373 to 623) K and up to 60 MPa. The liquid–gas critical loci behavior in the (Tc-x), (Pc-x), (ρc-x), and (Pc-Tc) projections, were studied based on the measured PρTx data. The values of the Krichevskii parameter for the (1-propanol + n-heptane) mixture were calculated using the measured critical curves data. Pure- and mixture-like behavior of the weakly (Cvx) and strongly (KTx and CPx) divergent properties has been studied based on measured critical curve data. The measured mixture molar volumes and pure components data were used to calculate the excess molar volumes. The values of the second virial coefficient of the mixture were calculated based on the measured PVTx data.