The thermal diffusion phenomenon was studied in detail by utilizing mixtures consisting of normal alkenes and two aromatics (n-Dodecane, Isobutylbenzene and 1,2,3,4-Tetrahydronaphtalene) based on comparison with available experimental data. This study presents the first report of a comparison of thermal diffusion coefficients of a ternary hydrocarbon mixture with experimental data in the literature. In addition to thermal diffusion coefficients, molecular diffusion coefficients are also measured and compared with Benchmark experimental values for three binary mixtures. Furthermore, molecular and thermal diffusion coefficients for three binary mixtures are used to correlate and estimate the thermal diffusion coefficients in the ternary hydrocarbon mixture. The thermo-solutal convection in porous media was simulated numerically using the Firoozabadi model in order to investigate the composition variation due to the processes of thermal diffusion and convection. Finally, a multi-porosity/multi-permeability model was utilized to further analyze the processes of thermal diffusion and convection in fractured porous media.