Development of phase change materials for low-temperature thermal energy storage application

Background: Energy storage is very critical for reducing the mismatch between demand and supply thus offering better management capabilities. It reduces the peak energy demand and increases efficiency, security, and reliability. There is unavailability of low-cost phase change materials (PCMs) in the lower temperature range. Methods: This study discusses the creation of eutectic from capric acid and paraffin wax. A series of blending of capric acid/paraffin wax (CA/PW) were prepared, having variable weight-composition. The thermophysical properties were obtained using differential scanning calorimetry, Further, thermal cycle testing was done to understand the thermal stability and reliability of the prepared eutectics. Results: The area underneath the peak is used to calculate the latent heat of fusion, and the tangent of the steepest slope at the peak of the crest is used to calculate the melting temperature (Tm). Differential scanning calorimetry results showed the developed eutectic had an appropriate melting temperature and adequate latent heat of fusion of 29.86 °C - 30.60 °C and 154.15–198.62 kJ/kg respectively, and can be used for various thermal energy storage applications in buildings, solar absorption chillers, surgical dress/clinical bed, and photovoltaic systems. Conclusions: The accelerated thermal cycle of the same confirmed its thermal stability up to 500 heating and cooling cycles. It was discovered that variable heating and cooling speeds had no significant influence on the melting temperature and latent heat of fusion of PW/CA eutectics. Further, the economic study revealed that the created PCM is inexpensive and readily available in the Indian market.