• 2026-05-08
• B.S. Adeboye, M.O. Idris, P.B. Idowu, A.A. Olaosebikan
• Volume 2, Issue 1

Abstract

This study investigated the production andand assess combustion characteristics of Brewers Spent Grain (BSG) - bituminous coal composite briquettes. Three processing variables were systematically varied: blending ratio (BSG:BC at 75:25, 50:50, and 25:75), compaction pressure (50, 100, and 150 kPa), and particle size (200, 250, and 300 µm). Cassava starch (30% w/w) was used as binder. The variables measured include shatter resistance, calorific value, ignition time, porosity, thermal efficiency, bulk density and combustion rate. The findings indicated that increasing the coal ratio from 25% to 75% led to an improvement in shatter resistance (78.0% to 91.0%), calorific value (18.50 to 20.15 MJ/kg), and thermal efficiency (33.5% to 36.1%) while reducing the porosity (7.2% to 3.0%) and combustion rate (4.55 to 3.77 g/min). The optimum briquettes were obtained with a higher compaction pressure of 150 kPa, which gave a shatter resistance of 90.0%, calorific value of 20.15 MJ/kg, minimum porosity of 3.0%, and thermal efficiency of 36.1%, with bulk density of 600 kg/m3. Smaller particle size (200 µm) produced the highest mechanical strength (90.0%) and calorific value (20.15 MJ/kg) while larger particle sizes (300 µm) marginally improved thermal efficiency (37.4%) because of higher porosity. The 25:75 (BSG:BC) blend, 150 kPa compaction pressure and 200 µm particle size were found to be the optimal conditions for producing quality briquettes. This research shows the potential of BSG–bituminous coal briquettes as an alternative solid fuel for household and small-scale industries.