Production and characterization of biochar derived from raw and anaerobically digested banana waste

Pyrolysis and anaerobic digestion (AD) of lignocellulosic wastes have gained increased attention as eco-friendly energy production technologies. Banana waste is produced in large quantities in tropical regions. This study investigates biochar production and characterization from raw and anaerobically digested banana waste under varying pyrolysis conditions. Increasing pyrolysis temperatures from 300 °C to 700 °C resulted in a decrease in biochar yield and cation exchange capacity (CEC) by 28.0–52.7 % and 77.8–93.6 %, respectively, while acetic acid adsorption capacity increased by 67.0–1143.3 %. Extending the pyrolysis residence time decreased biochar yields at lower temperature (300 °C) from 38.6 to 55.5 % to 33.6–51.5 %, but increased acid adsorption capacities at all temperatures by ~244 %. Raw banana waste outperformed anaerobically digested waste for biochar production, with CEC and acid adsorption capacities enhanced by ~359 % and 501 %, respectively. Biochars produced from banana wastes demonstrated 0.8–28.1 times higher CEC compared to wood-derived biochar, indicating that these materials are promising for agricultural and environmental applications.