Novel phase change materials for thermal energy storage: Evaluation of tropical tree fruit oils

We report for the first time the evaluation of oils from the tropical forest tree, Allanblackia, shea butter and palm kernel oil as a potential phase change material for thermal energy storage based upon its thermo-physical and chemical properties. Differential Scanning Calorimetry showed that all the oils were polymorphic and hence exhibited multiple melting/freezing profile over a wide range. For both melting and freezing cycles, Allanblackia oil showed high latent heat of energy (80.53 J/g) with the highest melting point profile (34.74 °C) of all the oils. Thermo-gravimetric analysis showed that all the oil samples were thermally stable and did not degrade within the temperature of interest even though Allanblackia oil showed an increase in weight around 37 °C indicating oxidative instability. Chemical stability was confirmed by FTIR spectra. Of all the oils studied, Allanblackia exhibited a potential for use as a PCM for thermal energy storage if purified to improve oxidative stability.