Utilization of waste apricot kernel shell derived-activated carbon as carrier framework for effective shape-stabilization and thermal conductivity enhancement of organic phase change materials used for thermal energy storage

In this study, low-cost and eco-friendly AC obtained from waste apricot kernel shells (ACAS) was utilized to simultaneously solve the inherited drawbacks and enhance thermal conductivity of (Capric-Myristic acid (CA-MA), Lauryl alcohol (LAOH), n-Octadecane (OD) and Polyethylene glycol (PEG)) as different type organic PCMs. The ACAS/PCM composites had high PCM loading rates of up to 75 wt%, hence a high latent heat capacity of up to 193.7 J/g. Their melting and freezing temperatures varied in the range of 20.21-26.61 degrees C and 18.37-28.78 degrees C, respectively. All the prepared composites exhibited high thermal degradation resistance as well as high cycling stability even after 1200 melting-freezing cycles. The thermal conductivity of ACAS/CA-MA, ACAS/LAOH, ACAS/OD and ACAS/PEG was measured approximately 2.61, 2.40, 2.27 and 1.75 times higher than that of pure CA-MA, LAOH, OD and PEG, respectively. The advantageous TES characteristics of leak-proof composites make them favourable PCMs for low-temperature thermal management of buildings. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, low-cost and eco-friendly activated carbon obtained from waste apricot kernel shells was used to improve the thermal conductivity of organic phase change materials (Capric-Myristic acid, Lauryl alcohol, n-Octadecane, and Polyethylene glycol) while addressing their inherent drawbacks. The composites showed high loading rates and latent heat capacity of the phase change materials, as well as excellent thermal degradation resistance and cycling stability. The thermal conductivity of the composites was significantly higher than that of the pure phase change materials, making them suitable for low-temperature thermal management of buildings.