Physical and mechanical properties of composite and pure briquettes produced from rice husk, groundnut shell and palm kernel shell using cassava starch

The increase in agricultural and industrial wastes, coupled with inadequate disposal methods, has led to severe environmental challenges. One sustainable solution is converting these wastes into bio-briquettes for domestic and industrial energy applications. This study evaluated the physical and mechanical properties of briquettes produced from rice husk (RH), groundnut shell (GS), and palm kernel shell (PKS), using cassava starch as a binder. The briquettes, both composite and single biomass, were assessed for relaxed density, water absorption, water resistance, shatter index, shatter resistance, and compressive strength. The relaxed densities ranged from 250 to 370 kg/m³, water absorption from 40.8% to 61.3%, and water resistance from 38.86% to 59.19%. Shatter index values were between 2.64% and 10.82%, with corresponding shatter resistance of 89.2% to 97.4%. The compressive strength, measured using a universal testing machine (UTM), ranged from 1.10 to 1.80 kN. Among the samples, the composite briquette with a 40:30:30 ratio of RH: GS: PKS showed superior mechanical strength and structural integrity, making it the most suitable for fuel applications.