Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Density and viscosity of monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG) and their binary, (50% MEG + 50% DEG), (50% MEG + 50% TEG), (50% DEG + 50% TEG), and ternary (33.33% MEG + 33.33% DEG + 33.34% TEG) mixtures have been simultaneously measured over the temperature range from 293 K to 465 K and at pressures up to 245 MPa using the hydrostatic weighing and falling-body techniques. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15 to 0.30%, 0.05%, 0.02 K, and 1.5 to 2.0% (depending on temperature and pressure ranges), respectively. Tait-type equation of state (EOS) for pure MEG, DEG, and TEG has been developed using the measured (p, rho, T) data. Theoretically based Arrhenius-Andrade and Vogel- Tamman-Fulcher type equation with pressure dependent coefficients was used to describe the temperature dependence of measured viscosities for pure polyethylene glycols.