Circular Economy in Charcoal Production: Valorization of Residues for Increased Efficiency and Sustainability

This study explores a circular economy approach in charcoal production, utilizing combustion gases from the process itself to optimize efficiency and quality, minimizing waste and reducing emissions. The research investigates the pre-drying of Eucalyptus sp. wood with these gases before carbonization, through an innovative system that directs gases from the carbonizing furnace to a separate drying furnace. Wood samples were dried at 120 °C and 150 °C for 15, 22.5, and 30 h before carbonization. The analysis included the gravimetric yield of charcoal, semi-carbonized wood, and fines, in addition to evaluating key charcoal properties. Results demonstrated that drying with combustion gases at 150 °C increased the charcoal yield by 7%, regardless of drying time. Furthermore, this pre-drying improved charcoal quality, raising fixed carbon content from 74.68% to over 81% and reducing volatile matter from 24.40% to below 18%. These findings highlight that the utilization of combustion gases for wood drying not only significantly enhances the efficiency and quality of charcoal production but also contributes to the reduction in greenhouse gas emissions, promoting a more sustainable and environmentally friendly alternative compared to conventional methods.