4. Results and discussion

In this section, the performance of the thermodynamic theory is examined to represent the thermal diffusion factors in a few selected binary gas and liquid mixtures.

### 4.1 Potential parameters

The intermolecular potential parameters along with molecular weight of the pure fluids involved in binary mixtures studied in this work are given in Table 1. Molecular parameters (ε/kB, Rm and α) are based on the correlation of the pure fluid viscosity and/or second virial coefficient data at the ambient pressure [25]. The unlike interaction parameters (Rmij, εij) were evaluated following the arithmetic rule for Rmij and geometric rule for εij. α was kept the same for all the fluids. The


#### Table 1.

(Exp-6) Potential parameters for the mixture components.

Thermodynamics of Thermal Diffusion Factors in Hydrocarbon Mixtures DOI: http://dx.doi.org/10.5772/intechopen.75639


Table 2.

Polynomial parameters of C\* (1,2).

pressure and potential parameters dependences of the unlike collision integrals are expressed in terms of a simple polynomial as given in Eq. (22) above. The polynomial parameters pi for the specific mixtures are given in Table 2. In this work, no effort was made to optimize the unlike energy, size and α parameters.
