Characterization of Community-Scale Smokeless Biochar Production from Corncobs for Potential Soil Amendment and Climate-Smart Agriculture

Open burning of agricultural residues remains a significant source of air pollution and greenhouse gas emissions in Southeast Asia. This study evaluated a community-scale smokeless vertical charcoal kiln for biochar production from corncob residues under practical operating conditions. Carbonization at 415–435 °C for 150–180 min produced biochar yields of 23.3–28.3%, with the 150 min treatment giving the highest yield. The biochar exhibited high carbon content (71–71.5%), low volatile matter (15.7–16.7%), fixed carbon content of 51–54%, and moderately alkaline pH (8.97–9.08). Atomic H/C and O/C ratios (approximately 0.55 and 0.27) indicated moderate aromaticity and stability consistent with IBI Class 1 criteria, while SEM revealed a macropore-dominated porous structure. Theoretical carbon sequestration potential was estimated at 0.69–0.74 tCO2-eq per tonne of dry feedstock. These findings demonstrate the technical feasibility of community-scale smokeless biochar production and provide physicochemical characterization of the resulting biochar, suggesting potential relevance for carbon storage and soil amendment; however, agronomic performance and emissions require direct evaluation, and results are specific to corncob feedstock. Overall, this work contributes to sustainable agricultural waste management by demonstrating a low-cost, community-accessible pathway that simultaneously supports climate change mitigation, air quality improvement, and socio-economic accessibility for smallholder farming systems in Southeast Asia.