Determination of thermal and mutual diffusivity of n-heptane with dissolved carbon dioxide by dynamic light scattering

In this work, thermal and mutual diffusivity of n-heptane (n-C7H16) with dissolved carbon dioxide (CO2) were simultaneously measured using dynamic light scattering (DLS) method from 298 to 473 K and saturation pressure up to 5.5 MPa. For this purpose, the DLS setup as well as temperature and pressure system were improved. Two hydrodynamic modes in connection with the statistical fluctuations of entropy and species were verified. The average expanded uncertainty of thermal and mutual diffusivity were 9.0% and 4.9% with a coverage factor of k = 2. The thermal and mutual diffusivity versus pressure under isothermal lines were briefly discussed and a comparison with literature was performed. The experimental thermal and mutual diffusivity measured in this work are in reasonable agreement with the literature data. This work is expected to provide fundamental data for engineering process. (C) 2020 Elsevier B.V. All rights reserved.