Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The isothermal (vapor + liquid) equilibria was measured for two binary systems including key apple odorants, (carbon dioxide + hexanal) and (carbon dioxide + ethyl-2-methylbutyrate) at (313.2, 323.2 and 333.2) K and pressures ranged from (2 to 10) MPa, using a methodology based on an analytic isothermal method without recirculation. No partial liquid miscibility was observed at the experimental conditions. The molar composition was assessed using gas chromatography for vapor phase, and a cold-trap with a wet test meter for the liquid phase. Experimental results were analyzed, estimating of the combined expanded uncertainty for the mole fractions, lower than 0.012 mol mol 1 for vapor phase and 0.021 mol mol 1 for the liquid phase, as well as, the evaluation of the thermodynamic consistency utilizing a test based on the point-to-point test of van Ness. In addition, the values measured were compared with those reported in literature for (carbon dioxide + hexanal). The Peng-Robinson equation state was used to model the (vapor + liquid) equilibria, with the quadratic van der Waals mixing rules including two adjustable parameters, and with the Wong-Sandler mixing rule plus the Non Random Two Liquid model for the calculation of the excess Gibbs energy.