Phase Equilibria in the Triethylene Glycol– and Tetraethylene Glycol–Supercritical Propane Systems

Phase equilibria in the triethylene glycol–propane and tetraethylene glycol–propane systems at 373, 378, and 383 K and 4 to 45 MPa were studied by IR spectroscopy. The compositions of the coexisting phases throughout the temperature and pressure ranges examined were calculated using the Soave equation with empirical binary interaction parameters. The critical lines for the binary systems likely have discontinuities in the vicinity of the critical point of propane.