Sustainable Biocomposite Phase Change Materials From Olive Wood and Fatty Acids for Thermal Energy Management

ABSTRACT This study addresses the critical challenges of low thermal conductivity, leakage, and limited energy storage capacity in traditional phase change materials (PCMs) by developing sustainable biocomposite PCMs (BCPs) using olive wood flour (OW) and plant‐based fatty acids (FA). A novel form‐stable BCP was synthesized by incorporating OW with graphite (G) to enhance structural stability and thermal performance. Chemical compatibility analysis via Fourier Transform Infrared (FT‐IR) confirmed no adverse interactions, ensuring material integrity. Thermogravimetric analysis (TGA) demonstrated that OW/G significantly improved thermal stability, while differential scanning calorimetry (DSC) revealed a high latent heat storage capacity of 110.8 J/g for OW/FA21/G, effectively preventing FA exudation. Shape stability tests showed minimal leakage rates (< 1.81%) after 20 thermal cycles, highlighting the composite's robustness. The incorporation of graphite significantly improved thermal heat transfer performance by 312.5% in the solid state (15°C) and 384.6% in the liquid state (35°C). Furthermore, OW accelerated melting‐solidification cycles, improving thermal response times, and minimized leakage via capillary forces in mesopores. These eco‐friendly composites overcome the limitations of traditional organic PCMs, offering a cost‐effective, scalable solution for thermal energy management in buildings and other energy‐efficient systems. The research highlights the potential of sustainable materials in advancing thermal energy storage technologies, with significant implications for reducing energy consumption and promoting circular economy practices.