Contribution to thermodiffusion coefficient measurements in DCMIX project

Abstract

In this work we carefully measured the thermodiffusion coefficient of four ternary mixtures of 1,2,3,4-tetrahydronaphthalene, isobutylbenzene and n-dodecane at 25 °C and at mass fractions of: 10/80/10, 10/10/80, 40/20/40 and 45/10/45 using the thermogravitational technique. In order to determine the reproducibility of the measurements we performed three different runs for each mixture. In addition, we have also measured the thermodiffusion coefficient of 13 binary mixtures composed of these components. The obtained values of transport properties for binaries agreed with recent measurements done by optical methods and they allowed analysing the validity of an additive rule to determine the thermodiffusion coefficient of ternary mixtures from binary thermodiffusion data. A good agreement between measured and calculated values of the thermodiffusion coefficient for the four ternary mixtures studied was obtained. This work completes the thermodiffusion results for this hydrocarbon ternary mixture which has been analysed at other two compositions in previous works.