An improved molecular dynamics algorithm to study thermodiffusion in binary hydrocarbon mixtures.

Area of Science:

• Physical Chemistry
• Thermodynamics
• Computational Science

Background:

• Temperature gradients induce diffusion flow in liquid mixtures, a phenomenon known as thermodiffusion or the Ludwig-Soret effect.
• Understanding thermodiffusion is crucial for controlling separation processes in multicomponent systems.

Purpose of the Study:

• To evaluate the performance of a boundary-driven non-equilibrium molecular dynamics approach using the enhanced heat exchange (eHEX) algorithm.
• To assess the thermodiffusion process in n-pentane/n-decane binary mixtures.

Main Methods:

• Employed non-equilibrium molecular dynamics simulations with the eHEX algorithm.
• Utilized transferable potentials for phase equilibria-united atom force field for accurate molecular interactions.
• Calculated Soret coefficients for n-pentane/n-decane mixtures at various compositions, temperatures, and pressures.

Main Results:

• The eHEX algorithm demonstrated improved energy conservation properties.
• Calculated Soret coefficients for n-pentane/n-decane mixtures showed excellent agreement with experimental data.
• The new molecular dynamics algorithm exhibited higher accuracy compared to existing methods.

Conclusions:

• The developed molecular dynamics approach with the eHEX algorithm is a reliable tool for studying thermodiffusion.
• This method provides accurate predictions of component separation in binary liquid mixtures.
• The findings contribute to the precise modeling of thermodiffusion phenomena.