Vapor pressures of binary mixtures of carbon dioxide with benzene,n-hexane and cyclohexane up to 7 MPa

The total vapor pressures of three CO₂C₆ hydrocarbon systems; CO₂benzene, CO₂n-hexane, and CO₂cyclohexane systems, have been measured at 273.15, 283.15, 298.15 and 303.15 K over the whole composition range by a bubble point method. For the CO₂n-hexane system, the densities of the liquid mixtures have also been measured. From the data and the calculated results by the Peng—Robinson equation of state, the activity coefficients of CO₂ and the Henry's constants of CO₂ in CO₂C₆ hydrocarbon systems have been obtained. The vapor pressure data have been compared with the results calculated by the Barker's method and by the Peng—Robinson equation of state with the use of four mixing models.