Physico-mechanical characteristics of rice husk briquettes using different binders

Abstract

This study evaluated the physico-mechanical characteristics of rice husk briquettes using plantain peels and gum Arabic as binders. The rice husk residues were milled into particle size of 1.18 to 0.6 mm, plantain peels and gum Arabic as binders at binder ratios of 10%, 20%, and 30% by weight of the rice husk residue. The two sets of briquettes produced were cylindrical in shape with a central hole using cylindrical die (70 mm height × 50 mm diameter) in a hydraulic press briquetting machine at a dwell time of 5 min, under a die pressure of 2.5 MPa. The physical and mechanical properties analyzed were moisture content, relaxed density, stability, durability index, water resistance index and compressive strength. The data obtained were statistically analyzed by Analysis of Variance (ANOVA) at significant difference of 0.05.
The test results showed that: the moisture content of the briquettes produced varied from 8.03% to 10.13%, relaxed density varied from 491.46 to 623.18 kg/m3. The durability index of the briquettes produced varied from 29.33% (30% plantain peel binder) to 93% (30% gum Arabic binder), compressive strength varied from 1.29 to 4.77 kN/m2. Both axial and longitudinal expansion of the briquettes took place within the first 30 minutes, though briquettes with gum Arabic as binder had better stability than those with plantain peels. Rice husk briquettes produced with gum Arabic as binder was more reliable, durable and can withstand mechanical handling than those with plantain peels as binder. However, both briquettes thus produced are viable fuels for domestic purposes in rural areas.