Partial miscibility behavior of the ternary mixture carbon dioxide plus n-tetradecane plus acetone

The liquid-liquid-vapor (llg) partial miscibility behavior of the mixture c arbon dioxide + n-tetradecane + acetone was experimentally studied by use o f a visual cell (stoichiometric) technique. Phase compositions and molar vo lumes of the two liquid phases in equilibrium are reported as functions of temperature and pressure within the llg region. The addition of the cosolve nt acetone extends the three-phase llg region in pressure-temperature space from the binary carbon dioxide + n-tetradecane llg locus downward in press ure, towards the vapor pressure curve of the cosolvent acetone. The three-p hase region is bounded from; above by an upper critical end point (1-1 = g) locus, which extends from the binary llg locus to a lower critical end poi nt (1 = 1g) locus, which bounds the region at lower pressures. The degree t o which the cosolvent acetone enhances the amount of the solute tetradecane present in the second (carbon dioxide-rich) liquid phase is compared to th at of methanol. (C) 2000 Elsevier Science B.V. All rights reserved.