Solid–liquid phase equilibrium study of binary mixtures of n-octadecane with capric, and lauric acid as phase change materials (PCMs)

Solid–liquid equilibrium (SLE) data for the organic binary mixtures of n-octadecane (1) + capric acid (2) (eutectic temperature TE = 295.15 K, eutectic composition x1E = 0.412, latent heat of melting of eutectic mixture ΔfusHE = 201 J g−1), n-octadecane (1) + lauric acid (2) (TE = 298.25 K, x1E = 0.704, ΔfusHE = 229 J g−1) were measured in this study using differential scanning calorimetry (DSC). All systems show simple eutectic behavior. These advantages of the two eutectic mixtures make them suitable in solar heating and for heat load leveling applications. The experimental data were correlated using the Wilson, NRTL and UNIQUAC activity coefficient models, respectively, and satisfactory results were presented.