Experimental Study of VLE Properties of n-Tetradecane in the Supercritical Binary Solvent (0.367 Propane/0.633 n-Butane)

A high-temperature and high-pressure optical cell VLE apparatus has been applied to measure phase equilibrium properties of n -tetradecane in the supercritical binary solvent (0.367propane + 0.633 n -butane mass fraction) at temperatures of 413.15 K, 433.15 K, and 453.15 K between of pressures (0.9 and 6.6) MPa. The combined expanded uncertainty of the temperature, pressure, and concentration measurements at 0.95 confidence level with a coverage factor of k = 2 is estimated to be 0.15 K, 0.0022, and 0.035, respectively. The critical parameters ( T C , P C , w C ) were determined based on the measured isothermal phase equilibrium data of the ternary system n -tetradecane + propane/ n -butane. It is shown that the critical temperature and pressure of the n -tetradecane + propane/ n -butane system increases with concentration of n -tetradecane increases.