Biomass materials require reduction and densification for the purpose of handling and space requirements. Guinea corn (Sorghum bi-color) is a major source of biomass material in the tropic regions. The densification process involves some measurable parameters, namely: pressure, particles size and binder ratio. Guinea corn residue was collected from the Teaching and Research Farm of the Federal Polytechnic at Bida in Nigeria. The moisture content was 9.08% dry basis (db). It was reduced and sieved into three particle sizes D1 (4.70 mm), D2 (1.70 mm) and D3 (0.60 mm). Starch paste of 40, 45, 50 and 55% was added as binder. Briquettes were produced using a hydraulic press and a cylindrical die (56 mmf) at the processing pressures of 7.5, 8.5, 9.5 and 10.5 Megapascal (MPa). The bulk density of the unprocessed material was 46.03 kg/m3. The mean relaxed briquettes bulk density was 208.15 kg/m3, which reflects a volume reduction of about 450%. The maximum density of the briquettes ranged from 789 to 1372 kg/m3. For the expansion characteristics, the maximum and minimum axial relaxation occurred in the first 30 min of the extrusion. All the processing parameters were found to be significant at P<0.05 test level for all the measured characteristics. The briquettes were kept for six months under ambient condition without deterioration.

 

Key words: Guinea corn, briquettes, residue, parameters.