Experimental measurement and modeling of the vapor-liquid equilibrium of carbon dioxide plus chloroform

Isothermal bubble and dew points, saturated molar volumes, and mixture crit ical points for binary mixtures of carbon dioxide + chloroform (trichlorome thane) (CO2/CHCl3) have been measured in the temperature region 303.15-333. 15 K and at pressures up to 100 bar. Mixture critical points are reported a t 313.15, 323.15, and 333.15 K. The data were modeled with the Peng-Robinso n equation of state using both the van der Waals-1 (vdW-1) mixing rule and the Wong-Sandler (WS) mixing rule incorporating the UNIQUAC excess free ene rgy model. The WS mixing rule provided a better representation of the data than did the vdW-1 mixing rule, though with three adjustable parameters ins tead of one. The extrapolating ability of both of the mixing rules was inve stigated. Using the parameters regressed at 323.15 K, the WS mixing rule yi elded better extrapolations for the composition dependence at 303.15, 313.1 5, and 333.15 K than the vdW-1 mixing rule. (C) 2001 Elsevier Science B.V. All rights reserved.