Effects of Methanol Modification on the Physicochemical Properties of Coconut Shell Biochar

Production of biochar for nano-adsorbents requires advanced technology and substantial energy input for large-scale production. This study evaluated the impact of surface modification using methanol on the properties of coconut shell biochar after low energy self-sustained carbonization. Methanol serves as a mild modifier that may alter surface polarity, improve pore accessibility, and enhance the availability of active sites for adsorption without complex processing. Self-sustained carbonization was carried at 300–500 °C for less than 300 minutes at low retention times. Subsequently, the produced biochar was modified by mixing it with methanol at 130 rpm for 24 hours. The modified biochar showed significant improvements, where BET surface area increased from 1.54 ± 0.02 to 158.18 ± 0.67 m²/g and total pore volume from 0.0005 ± 0.004 to 0.09 ± 0.06 cm³/g. This was supported by SEM images which indicate pore network development with increased porosity and surface roughness, suggesting the modified biochar’s potential as an adsorbent. These results underscore the feasibility of developing effective adsorbents through appropriate technology for the coconut industry and environmental protection.