Correlations for the Viscosity and Thermal Conductivity of Tetrahydrofuran

We present hybrid predictive-correlative engineering correlations for the calculation of the viscosity and thermal conductivity of tetrahydrofuran (THF) in the fluid phase. They incorporate critically evaluated experimental data where available, and predictive methods in regions where there are no data and can be applied over the gas, liquid, and supercritical phases. The viscosity correlation is validated from 195 K to 353 K, and up to 30 MPa pressure, while the thermal conductivity is validated in the temperature range 174 K to 332 K, and up to 110 MPa pressure. Both correlations are designed to be used with a recently published equation of state that extends from the triple point to 550 K, at pressures up to 600 MPa. The estimated uncertainty (at a 95 % confidence level) for the viscosity is 10 % for the low-density gas (up to atmospheric pressure), and 6 % for the liquid at temperatures up to 353 K and pressures up to 30 MPa. For thermal conductivity, the expanded uncertainty is estimated to be 15 % for the low-density gas, and 2 % for the liquid phase from the triple-point temperature to 330 K at pressures up to 15 MPa, rising to 4 % at 110 MPa. Due to the extremely limited data available, these correlations should be considered preliminary until further experimental data become available.