Phase behavioral study of binary systems for the vinyl Benzoate, vinyl pivalate and vinyl octanoate with carbon dioxide at high-pressure

The experimental phase-behavior data is reported at high-pressure for the mixtures of vinyl benzoate, vinyl pivalate and vinyl octanoate with supercritical carbon dioxide (sc-CO₂) at pressure and temperature array of 3.42 MPa to 22.19 MPa and 313.2 K to 393.2 K respectively. In pressure vs temperature space, the binary mixtures show the continuous critical curves between carbon dioxide critical point and that of other component critical point exhibiting maximum in between. The solubility of vinyl benzoate, vinyl pivalate and vinyl octanoate in sc-CO₂ is observed to increase with increasing temperature. Moreover, the (sc-CO₂ + vinyl benzoate), (sc-CO₂ + vinyl pivalate), and (sc-CO₂ + vinyl octanoate) systems demonstrate type-I phase performance. The experimental outcomes are modeled with Goderao-Dalvi-Narayan (G-D-N) and Peng-Robinson (P-R) cubic equations of state. The pressure vs composition (P vs x) isotherms were predicted with Van der Waals one-fluid mixing rules having pair of interaction parameters. The theoretical (P vs x) isotherms of the (sc-CO₂ + vinyl benzoate), (sc-CO₂ + vinyl pivalate), and (sc-CO₂ + vinyl octanoate) systems in range of temperature 313.2 K–393.2 K are in decent agreement with the experimentally derived data.