Preparation and thermal properties of capric acid/palmitic acid eutectic mixture as a phase change energy storage material

This study focuses on the preparation, thermal properties and thermal reliability of capric acid (CA)/palmitic acid (PA) mixture as phase change material (PCM) for low temperature latent heat thermal energy storage (LHTES). The differential scanning calorimetry (DSC) results indicated that the CA/PA mixture with eutectic composition (76.5/23.5 wt.%) was suitable PCM for low temperature LHTES applications in terms of melting and freezing temperatures (T_m = 21.85 °C; T_f = 22.15 °C) and latent heats of melting and freezing (ΔH_m = 171.22 J/g; ΔH_f = 173.16 J/g). The thermal properties make it potential PCM for LHTES systems used in heating, ventilation, and air conditioning applications. Accelerated thermal cycling tests showed that the eutectic mixture as a PCM has good long-term thermal reliability. The probable reasons of the changes occurred in thermal properties of the PCM during accelerated thermal cycling were also investigated using Fourier Transform Infrared (FT-IR) spectroscopy method.