Phase transitions and volumetric properties of the ternary system water+1-propanol+n-hexane near the critical point

Abstract

One-phase PVTx, phase transition (ps, ρs, Ts) and critical (pc, ρc, Tc) properties of the ternary equmolar system (0.333 mole fraction of each component) water+1-propanol+n-hexane were experimentally studied in the critical and supercritical regions. Measurements of the PVTx relationship were made using a high-temperature, high-pressure, constant-volume piezometer immersed in high precision air thermostat. The values of the phase transition parameters were determined using isochoric P-T break point technique. The standard uncertainty of the density, temperature, pressure, and concentration measurements was estimated to be 0.15%, 0.015 K, 0.05%, and 0.01 mole %, respectively. The measured PVTx data for the ternary mixture water+1-propanol+n-hexane were used to develop wide-ranged multiparametric equation of state.