Interfacial and bulk properties of vapor-liquid equilibria in the system toluene + hydrogen chloride + carbon dioxide by molecular simulation and density gradient theory + PC-SAFT

Interfacial and bulk properties of vapor-liquid equilibria (VLE) in systems containing toluene, hydrogen chloride (HCl), and carbon dioxide (CO2) are studied by molecular dynamics simulations and density gradient theory + PC-SAFT. The pure components, the three binary mixtures, and the ternary mixture are studied systematically. A new PC-SAFT model of HCl is developed and mixture models are adjusted to binary VLE data. The focus of the studies is on the temperatures 333 and 353 K for which both HCl and CO2 are supercritical. The simulation results are compared to experimental data, where such data are available. VLE bulk properties are well described. For the interfacial tension, only pure component data are available, which are well predicted. For the mixtures, data on the interfacial tension are predicted. A strong adsorption of both HCl and CO2 at the vapor-liquid interface is found from both methods.