A Comparative Study of Predictive Models for Densification Parameters of Briquettes Produced From Two Species of Corncob Oladeji

Corncob is a renewable energy resource, which its great potential for renewable energy generation has not been fully utilized. Corncobs from white and yellow maize were selected, sun-dried and their moisture contents were determined using ASAE standard. The residues were subjected to size reduction process and three particle sizes 4.70, 2.40 and 0.60 mm were selected. Starch mutillage (binder) was added to the residues at three levels of percentage binder ratios 20, 25, and 30 % by weight of the residue. A briquetting machine was used to form briquettes at three levels of pressures of 2.40, 4.40 and 6.60 MPa with observation of a dwell time of 120 seconds. The bulk density of the unprocessed materials and relaxed briquettes were determined using ASAE standard. The initial, maximum and the relaxed densities of the briquettes were determined using the mould dimension, the relaxed briquette’s dimension and ASAE standard method of determining densities. Also determined were the compaction, density and relaxation ratios of the formed briquettes. Percentage axial and lateral expansions were also determined. The experimental data were subjected to regression analysis. A statistical package SPSS version 11.0 was used. The regression coefficients for the maximum density, relaxed density, compaction ratio, density ratio, relaxation ratio, axial expansion and lateral expansions for briquettes from white maize are 0.72, 0.81, 0.85, 0.84, 0.77, 0.86 and 0.81 respectively, while the corresponding values for briquettes from yellow maize are 0.97, 0.77, 0.98, 0.92, 0.96, 0.82 and 0.84. The study concluded that there is no significant difference between experimental and predicted results. Hence, all the developed models are