Measurement of Thermal Diffusivity of n-Pentane from (293–573) K and up to 10.0 MPa in the Near-Critical and Supercritical Regions

Transport properties of n-pentane are so scarce that it prevents the further studies of n-pentane as an important component of industrial fluids, especially in the near-critical and supercritical regions. In this work, the thermal diffusivity of n-pentane was measured by the dynamic light scattering method within the temperature limits of (293–573) K along six isobaric lines at p = (0.1, 3.0, 3.5, 5.0, 7.5, and 10.0) MPa. The relative uncertainty of the thermal diffusivity experimental system is estimated to be 2.6% for a coverage factor of k = 2 with a level of confidence of 0.95. The influences of temperature and pressure on thermal diffusivity were presented. Besides, we compared the experimental data with the calculated values from the thermal conductivity model proposed by Vassiliou et al. and the multiparameter equation of state proposed by Span and Wagner. The absolute average of relative deviation and maximum deviation between the experimental data and the calculated results are 1.12 and 3.74%, respectively.