Assessment of Physicochemical and Thermal Characteristics of Selected Agricultural Wastes for Briquettes Production

The increasing demand for sustainable energy solutions and the need for effective agricultural waste management underscore the importance of biomass briquettes as an alternative energy source. This study evaluates the physicochemical and thermal characteristics of three selected agricultural wastes. Sesame stalk, melon shell, and cassava peel using standard ASTM procedure for their suitability in briquette production. Proximate analysis revealed that cassava peel exhibited the highest fixed carbon (66.67% raw, 71.50% carbonized) and the lowest ash content in its raw state (5.83%), indicating superior energy density and clean combustion potential. Conversely, melon shell showed the lowest moisture content (5.50% carbonized) and the highest volatile matter (34.50% carbonized), making it ideal for quick ignition. Sesame stalk provided balanced characteristics, with moderate fixed carbon (55.50% carbonized) and ash content (18.5% carbonized), making it suitable for blending. Ultimate analysis confirmed cassava peel's dominance in carbon content (75.45%) and hydrogen content (4.48%), enhancing its energy yield. Thermal analysis (TGA/DTA) further highlighted cassava peel's stable thermal degradation and significant heat release, while melon shell exhibited rapid degradation due to high volatile matter. Sesame stalk displayed gradual degradation, indicating steady energy output. The findings suggest cassava peel as the most promising raw material for energy-dense briquettes and sesame stalk can complement its properties in blended briquettes, while melon shell can be utilized for quick ignition fuels. The study highlights the potential of utilizing the selected agricultural residues for briquette production, offering sustainable energy alternatives and contributing to waste management in Nigeria.