Evaluation of Biomass Briquette Physical Properties for Rural Energy Applications in Benue State

Biomass briquettes produced from agricultural residues offer a cleaner and more energy-dense cooking fuel alternative to firewood for rural households in North Central Nigeria, reducing deforestation pressure and indoor air pollution. Benue State generates substantial quantities of rice husk, sorghum stalks, and cassava peel that can be valorised as briquette feedstocks. This study evaluates the physical properties of biomass briquettes produced from five feedstocks including rice husk, sorghum stalks, cassava peel, groundnut shells, and corn cobs at the Centre for Renewable Energy in Makurdi. Briquettes are produced using a hydraulic piston press at pressures of 5 and 10 MPa. Proximate analysis, gross calorific value by bomb calorimetry, compressive strength, bulk density, and water absorption are determined for each briquette type. Results indicate gross calorific values ranging from 14.2 MJ per kilogram for cassava peel briquettes to 19.8 MJ per kilogram for groundnut shell briquettes. Compressive strength values of 2.3 to 5.6 MPa are adequate for transport and handling resistance. Rice husk briquettes show the highest ash content of 18.4 percent, which limits their combustion quality. Groundnut shell briquettes at 10 MPa compression achieve the optimal combination of high calorific value, low moisture absorption, and adequate mechanical strength. Keywords: biomass briquette, calorific value, Benue State, agricultural residue, rural energy