PHASE BEHAVIOR DATA AND THERMODYNAMIC MODELING OF THE BINARY SYSTEM {CO2 + COUMARIN} AT HIGH PRESSURES

Abstract In this work, vapor - liquid (VLE) equilibrium for the binary system carbon dioxide (1) + coumarin (2) at high pressures was measured by a static synthetic method using a variable-volume view cell. Experimental data were obtained in the temperature range of 318 - 338 K and pressures up to 20 MPa. Coumarin molar fraction ranged from 3.0x10-3 to 6.0x10-3. Coumarin melting point reduction at high pressures was observed. The experimental results were modeled using the Peng-Robinson (PR) equation of state with van der Waals quadratic mixing rules (vdW - QMRs), providing a good representation of the experimental phase equilibrium data. Critical properties and the acentric factor were estimated using the Constantinou and Gani method, which showed to be satisfactory on the quality of data correlation. Results indicate coumarin solubility increases with increasing phase transition pressure at a given temperature.