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PVTx Measurements for Water + Toluene Mixtures in the Near-Critical and Supercritical Regions



Emil Bazaev, Ilmutdin Abdulagatov, Joe W. Magee, Michail Rabezkii, Asbat E. Bazaev


The PVTx relationships of dilute (1 – x)water + x toluene mixtures were measured in the near-critical and supercritical regions, with a constant-volume peizometer immersed in a precision thermostat. The ITS-90 temperature was measured with a 10 Ω} platinum resistance thermometer (PRT-10) with an uncertainty of 10 mK. Pressure was measured by means of a dead-weight gauge with an uncertainty of 1.5 – 2.0 kPa. Uncertainties of the density measurements are estimated to be 0.05 – 0.15%, depending on the experimental pressure and temperature. The uncertainty in composition measurement is 0.001 mole fraction. Measurements were made on near-critical and supercritical isotherms between 623 and 673 K at pressures from 11 to 46 MPa and densities between 54 and 579 kg&#8226m-3 for three composition mole fractions of toluene (0.0008, 0.0022. and 0.0085). The measured PVTx data for (1 – x) water + x toluene mixtures were compared with values calculated from a recently developed crossover equation of state and published measurements. The PVTx measurements were used to derive values of the Krichevskii parameter, excess volumes, and apparent molar volumes. The method of isochoric break points was used to extract the phase transition temperatures and pressures for each measured isochore. The critical anomalies of the supercritical (1 – x)water + x toluene mixtures and the behavior for the Krichevskii function near the solvent's (water) critical point are discussed.
Journal of Supercritical Fluids


Bazaev, E. , Abdulagatov, I. , Magee, J. , Rabezkii, M. and Bazaev, A. (2001), PVTx Measurements for Water + Toluene Mixtures in the Near-Critical and Supercritical Regions, Journal of Supercritical Fluids (Accessed April 15, 2024)
Created October 3, 2001, Updated October 12, 2021