A novel bio-based phase change material of methyl palmitate and decanoic acid eutectic mixture: Thermodynamic modeling and thermal performance

One of the most sustainable methods of energy management is thermal energy storage using renewable phase change materials. Phase change materials (PCMs) with high latent heat can store thermal energy when available and release it effectively when required. In this study, the thermal properties of a set of binary mixtures of methyl palmitate (MP) and decanoic acid (DA) have been evaluated as a new bio-based and renewable PCM. Both phase change materials are obtained from vegetable oil and are biomass-based materials. The results show that the binary eutectic mixture consisting of 30% MP and 70% DA has the desired properties as a PCM for applying as thermal energy storage in the building materials. These features include the convenient melting and freezing temperatures (T_m = 20.19 °C, T_f = 15.08 °C) and the high value of corresponding latent heats (ΔH_f =202.3 J^.g⁻¹, ΔH_m = 201.43 J^.g⁻¹). Evaluating other thermo-physical properties of this mixture also confirms its fitness for the PCM role. The composition and melting point of the eutectic point and the solid-liquid phase equilibrium for these mixtures were predicted by several thermodynamic models from which UNIQUAC showed the lowest Average Relative Deviation percentage (ARD%) of 0.29%.