EXPERIMENTAL INVESTIGATION OF THE PVTX-PROPERTIES OF N-HEPTANE IN SUPERCRITICAL WATER

The results of an investigation of the PVTx-properties of a water+n-he ptane binary system near the critical point of pure water are given. T he measurements were carried out using a constant-volume piezometer pl aced into an air thermostat. The experiment was performed on two super critical isotherms of 653.15 and 673.15 K at pressures of up to 30 MPa and concentrations from 0 to 1 molar fraction of n-heptane. With rega rd to density, this range covers the region from 950 to 2500 mol/m(3). The excess molar volumes, partial molar volumes of components, and ap parent molar volumes are calculated from the experimental data. The ex perimental data on molar volumes confirm the nonclassical (scaling) be havior of the partial molar volume of n-heptane near the critical poin t of pure solvent (water). The asymptotic properties of partial molar volumes are investigated near the critical point of pure water.