Thermodiffusion and molecular diffusion in binary n-alkane mixtures: experiments and numerical analysis

Abstract

New experimental data on the thermodiffusion and molecular diffusion coefficients of nine non-equimolar binary mixtures of () at 298 K and 1 atm have been reported. The data have been obtained using a combination of the thermogravitational column and the sliding symmetric tubes technique, respectively. It was found that with an increase in the disparity between the two components, the Soret effect becomes more dominant. Further, the stronger Soret effect weakens the molecular diffusion process. These trends are observed in the form of an increase in magnitude of the thermodiffusion coefficient and a decrease in the magnitude of the molecular diffusion coefficient. Numerical analysis was also performed using the principles of non-equilibrium thermodynamics. The model was able to predict the experimental data as well as the trends fairly accurately.

Keywords:

• experiments
• thermodiffusion
• molecular diffusion
• hydrocarbons
• numerical simulation

Acknowledgments

The authors would like to acknowledge the financial support of the Canadian Space Agency, NSERC and the Basque Government (grants – Research Groups (IT557-10), GOVSORET3 (PI2011-22) and MICBIO2).