Abstract The growing demand for sustainable fuel alternatives highlights the need to optimize agricultural waste briquettes, as their current performance in terms of energy output and durability remains limited for consistent daily use. In this study, briquettes were produced from carbonized agricultural wastes (cocopeat, corn cobs and bean shell) using starch and clay as binder. Central Composite Design (CCD) of Response Surface Methodology (RSM) was used to investigate the effect of binder type, biochar type, binder percentage and amount of water on calorific value, compressive strength, ash content and shatter index. Carbonization was performed by conventional heating at temperatures ranging from 300 – 500 °C and residence times of 45 min – 120 min. RSM analysis showed that the experimental results were most accurately described by quadratic models. The parameters were optimized at 91.08 mL of water, 34.14% starch binder, and corn cob biochar, resulting in a calorific value of 17.86 MJ/kg, compressive strength of 21.61 N/mm 2 , shatter index of 99.82%, and ash content of 5.59%. This study supports the development of alternative fuels for domestic use in developing and underdeveloped countries.
Osei-Owusu et al. (2026) studied this question.