No abstract

Ultrasonic velocity measurements were carried out on two ternary mixtures at pressures up to 150 MPa and within a temperature interval of 293 K-373 K. The first of these two mixtures, which was selected to simulate a distillation cut close to 423 K, is made up (in mass percentage) of 40% nonane, 35% cyclooctane and 25% propylbenzene; the second, made up of 40% undecane, 35% pentylcyclohexane and 25% pentylbenzene has a boiling point of approximately 473 K. The acoustic measurements were then used to characterize the ppT behaviour of these two ternary mixtures in the liquid state. They also provided indirect access to the isentropic and isothermal compressibility coefficients of these mixtures.