Activated carbon foam composite derived from PEG400/ Terminalia Catappa as form stable PCM for sub-zero cold energy storage

Abstract

A novel form-stable phase change material (FSPCM) for cold energy storage has been developed using sea almond (SA) (Terminalia catappa) derived supporting matrix and polyethylene glycol 400 (PEG 400) as the basic phase change material (PCM) for energy storage. A two-step method based on pyrolysis followed by KOH activation was implemented to produce activated carbon (SAS-AC) from the sea almond shell, an agricultural waste. The SAS-AC possessed a high specific surface area and a total pore volume of 1842.6 m2/g and 0.9275 cm3/g, respectively. The Activated carbon foam (SAS-ACF) was used as the supporting matrix for the PCM. Good chemical compatibility observed between the PCM and the SAS-ACF was validated using Fourier transform infrared analysis. The contact angle of 46.6o found between PEG 400 and SAS-ACF confirmed excellent wettability. The thermal conductivity of the FSPCM was found to be 0.411 W/m K, which was 82.66% higher than that of pristine PEG 400 (0.225 W/m K). A melting temperature and an enthalpy of −6.87 °C and 26.53 J/g were obtained for the FSPCM. Thermogravimetric analysis (TGA) proved the excellent thermal stability of FSPCM. The performance of the FSPCM was analyzed using a custom made experimental setup. All the results indicated that the developed FSPCM has a great potential to be used as a cold energy storage medium.