Influence of Compaction Parameters and Biomass Composition on Briquettes Produced from Cocoa and Kolanut Pod Residues

The sustainable utilization of agricultural residues for solid biofuel production offers a viable pathway for improving energy access and waste management in biomass-rich regions. This study investigates the influence of compaction parameters and biomass composition on briquettes produced from cocoa pod husks and kolanut pod husks using a locally fabricated briquetting machine. Briquettes were produced under varying mould heights, binder concentrations, biomass mixing ratios, and drying temperatures, and evaluated for bulk density, shatter index, fracture resistance, moisture content, and compressive strength. Results showed that compaction geometry and material composition significantly affected briquette quality, with bulk density ranging up to 0.006 g/cm³ and durability indices exceeding 90% under optimal conditions. A mould height of 4 mm, binder concentration of 5–10% starch, and balanced cocoa–kolanut pod ratios yielded the best combination of density and mechanical stability, while drying at 220°C enhanced moisture removal and strength development. Statistical analyses confirmed that mould height and biomass composition were the dominant factors influencing briquette performance, with drying temperature playing a key role in energy absorption and structural consolidation. The findings demonstrate that cocoa and kolanut pod residues can be effectively valorized into durable solid biofuels through optimized compaction and processing conditions, highlighting their potential for sustainable household and small-scale energy applications.