Akademik Veri Yönetim Sistemi
Biomass and Bioenergy, cilt.205, 2026 (SCI-Expanded, Scopus)
The current experimental study aims to develop form-stable phase transition materials to harvest solar energy by utilizing acid activated biochar derived from spent coffee beans as porous support to intensify the thermal behaviour of eutectic mixture of beeswax (BW) and myristic acid (MA). In an effort to obtain biochars that possess high surface area, dehumidified spent coffee was activated by saturating in 0.6M ZnCl2 solution for about 48 h followed by carbonization at 550 °C (CB550) and 750 °C (CB750) in restricted oxygen environment. The BET surface area of CB550 and CB750 was 305.2 m2/g and 720.5 m2/g respectively. To further enhance the rate of heat transfer, nano TiO2 was infused at 1 wt% concentration. The encapsulation rate of eutectic has increased up to 75 wt% and 80 wt% in case of CB550 and CB750 respectively and corresponding latent heats during melting phase were recorded as 106.29 J/g and 118.03 J/g. Besides, the composites were stable till 180 °C as per TGA analyses and the thermal conductivity of CB550/BMA and CB750/BMA composite increased by 111.7 % and 79.56 % respectively. Notably, the developed nano-enhanced composites were durable for 500 thermal cycles with marginal variation in energy storage capacity. The thermal and chemical characteristics of (CB550 or CB750)-TiO2/BMA composites enables their application in heat pumps, solar water heaters and room heaters, contributing toward cleaner environment and bringing circular economy.