Calculation of the T – X phase diagram of tetradecane + hexadecane and tetradecane + pentadecane under high pressure by the landau mean field theory

Abstract

Landau phenomenological model is applied to two binary mixtures (tetradecane + hexadecane and tetradecane + pentadecane) to calculate T−x (temperature - composition) phase diagram under high pressure for their solid – liquid equilibria. The phase line equation derived from the free energy of the solid phase is fitted to the experimental liquidus curve (T−x) from the literature and the parameters in the Landau expansion are determined. As observed experimentally, variation of the temperature with the composition below and above Te (minimum melting temperature) is almost linear at the pressures from 0.1 to 100 MPa in these binary mixtures. Our results indicate that the influence of pressure on liquid – solid equilibria can also be studied for the other binary mixtures or two – components systems by the Landau mean field model, as studied here. © 2022 Elsevier B.V.