APPLICATION OF A GENERALIZED MULTIPROPERTY APPARATUS TO MEASURE PHASE-EQUILIBRIUM AND VAPOR-PHASE DENSITIES OF SUPERCRITICAL CARBON-DIOXIDE IN NORMAL-HEXADECANE SYSTEMS UP TO 26 MPA

A high pressure multi-property apparatus has been developed to measure several thermodynamic and transport properties. In this study the apparatus has been applied to measure phase and volumetric properties of supercritical carbon dioxide in hexadecane from low pressures to the very vicinity of the critical pressure. The experimental data have been successfully fitted over the entire range of the experiment using the Wilson-Wegner expansion including the use of the latter to obtain an improved estimate of the critical pressure and composition. The relation between the occurrence of multiple condensed phases (at some lower temperature) and supercritical extraction is discussed.