Optimization of eco-friendly Pinus resinosa biochar-dodecanoic acid phase change composite for the cleaner environment

Abstract

The use of waste materials in sustainable energy forms has gained a tremendous research focus, which has risen the trend of energy demand coupled with environmental concerns. Contemplating that, biochar material from organic waste has been considered as shape stabilizing materials for the organic phase change materials (PCMs) aiming for thermal energy storage (TES) applications. Pinus resinosa (PR) fruits have been pyrolyzed into biochar which has exhibited a highly porous and channel-like morphology with a surface area of 27.99 m(2)/g. Dodecanoic acid (DA) in 1:1, 2:1, 3:1, and 4:1 ratios have been incorporated into the PR biochar for the fabrication of shape -stabilized phase change composites (DAPR). The highest melting and solidification enthalpies are exhibited by the DAPR-4 composite, though the values are almost similar to the DAPR-3 composite. Therefore, 3:1 DA to PR biochar can be considered as the optimum ratio. The maximum encapsulation efficiency and ratio are calculated to be 32.53 % and 32.66 %, respectively while the highest melting enthalpy is obtained at 50.87 J/g. All the DAPR composites have demonstrated admirable leakage-proof performance at elevated temperatures along with the congruent thermal cycle resilience up to 100 cycles of heat charging and discharging, without any alteration in temperatures and enthalpies. The exceptional thermal and structural stabilities manifested by the DAPR samples are ascribed to the capillary action, surface functionality, and space confinement effects of the biochar.