Effect of Particle Size on Quality of Briquettes Produced from Sawdust of Daniella oliveiri and Gmelina arborea in Makurdi, Benue State, Nigeria

Abstract

The effect of particle size on the quality of briquettes produced from sawdust of Daniella oliveiri and Gmelina arborea was determined using some properties such as Compressed and Relaxed Density, Shattered Index and Combustion properties of the briquettes produced. The sawdust samples were collected from Timber Market in Northbank Makurdi Benue State Nigeria, sundried for 7 days and sieved into three different sizes; 1.70 mm, 2.36 mm and 3.35 mm.  Starch binder was used in producing the briquettes in the proportion of 25% to 100 g of sawdust sample. The briquettes were produced in the Mechanical Engineering Laboratory of the University of Agriculture Makurdi. The experimental design was based on a 2 x 3 Factorial in Completely Randomised Design (CRD). Data was collected to determine Compressed Density at 0 minutes and relaxed Density at 30 minutes, 1 hour, 24 hours and 7 days: Shattered index and Combustion properties of the briquettes produced. The result showed a gradual reduction in compressed and relaxed density of briquettes as drying time increased from 0 minutes to 7 days. There was also an observed decrease in density as particle size of briquettes increased from 1.70 mm to 3.35 mm. The species densities did not show any significant differences, though Gmelina arborea recorded a higher relaxed density of 0.32 g/cm3 in 7 days. The effect of species and particle size were not significant on Shattered index, where as Gmelina arborea had a shattered resistance of 99.9% .There was no significant difference in the heating values of the briquettes produced from three particle sizes, but Gmelina arbore are corded a higher Specific heat of 4947.80 Kcal/kg compared with Daniella oliveiri with 4919.30 Kcal/kg. The assessment showed that particle size had no significant effect on the quality of briquettes produced from the two species. Therefore sawdust particles of Daniella olivieri and Gmelina arborea are suitable sources of material for briquettes production in Nigeria.