Valorization of Urban Tree Pruning Residues: Carbonization of Ficus benjamina Biomass at 400-600 °C for Biochar Production

Urban tree pruning generates significant quantities of lignocellulosic biomass requiring sustainable valorization strategies. This study valorized Ficus benjamina (Fb) pruning biomass through carbonization at 400, 500, and 600 °C for 2 h under oxygen-limited conditions, evaluating of the influence of temperature on physicochemical properties and potential applications of the resulting biochar. The biochars were characterized for proximate and elemental composition, calorific value, combustibility index and volatile ignition index. Increasing carbonization temperature significantly decreased (p < 0.05) volatile matter (26.58 to 17.04 %), hydrogen content (2.71 to 1.76 %), mass yield (34.32 to 28.59 %) and energy yield (51.60 to 39.96 %), while fixed carbon (62.93 to 69.55 %), carbon content (66.71 to 68.93 %), and ash content (10.49 to 13.41 %) increased progressively. Carbonization at 500 °C yielded biochar exhibiting enhanced aromatic condensation, reduced hydrophilicity, high calorific value (24-26 MJ kg.¹), and exceeding the volatile ignition index threshold of 14 MJ kg.¹, rendering it suitable for thermochemical energy recovery. These findings demonstrate that valorization of urban pruning biomass through controlled carbonization constitutes a viable pathway for integrated waste management and value-added carbonaceous material production.