Hydrochars from Forgotten Residues: Solutions for Green Electronics

The electronics industry is among the world's most polluting sectors, with materials posing significant risks to health and the environment. This research demonstrates the valorization of residual biomasses through hydrothermal carbonization (HTC) to produce sustainable alternatives for electronic applications, supporting a circular economy model. Various agro-industrial residues including Galapagos and Cumbaya blackberry bushes, mango endocarps, and palm husks were processed via HTC at different temperatures (from 175°C to 250°C) and durations (1-2 hours). The resulting hydrochars were characterized using semiconductor analyses, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Results revealed that mango endocarps, palm husks, and blackberry bushes exhibited high relative permittivity (between 10-15) and low loss tangent values (lesser than 0.06) in the range of low frequencies, making them suitable for dielectric and insulating applications. XRD and SEM analyses confirmed that HTC treatment modifies biomass structure, enhancing the formation of better-organized cellulose structures appropriate for dielectric materials. The findings demonstrate that hydrochars from agricultural residues represent a promising green solution for replacing conventional insulators and dielectric materials in the electronics industry, thereby promoting circular economy principles and environmental sustainability.