Phase Equilibria of the Systems CO2 + Styrene, CO2 + Safrole, and CO2 + Styrene + Safrole

This work reports phase equilibrium experimental data of binary and ternary systems involving carbon dioxide (CO2), 5-(2-propenyl)-1,3-benzodioxole (safrole), and ethenylbenzene (styrene). The experimental phase equilibrium data were measured using a high-pressure variable-volume view cell based on the static synthetic method in the temperature range of (303 to 343) K, at several CO2-overall compositions and pressures up to 16 MPa. For ternary system measurements, solutions of safrole and styrene with styrene mass fractions of 0.75 and 0.90 on CO2 free basis were prepared. The results showed that, in the experimental range investigated, only vapor–liquid equilibria (VLE) were detected with bubble (BP) and dew (DP) point transitions. The experimental data were satisfactorily represented by the Peng–Robinson equation of state (PR-EoS) with the classical quadratic mixing rules. The EoS interaction parameters were fitted from binary systems and then used to predict the phase behavior of the ternary system with a good agreement.