Enhancement of the mechanical properties of sawdust briquette using mung beans waste

Abstract

This research was undertaken to enhance the efficiency of sawdust briquette using mung beans waste. Mung beans waste (MB) was blended with sawdust briquette to investigate the effect on the mechanical properties (hardness, porosity index, durability, compressive strength, bulk density and mass). Prior to the blending of the sawdust and mung beans waste, proximate analyses (moisture content, fixed carbon, ash content, volatile matter content and calorific value) were carried out on the mung beans waste and the sawdust to ascertain their suitability for biofuel production. The analyses were carried out using standard methods. The briquettes were produced at different sawdust to biomass ratios (100%:0%, 70%: 30%, 50%:50%, 30%:70% and 0%:100%) using cassava starch binder. The result of the analysis shows that the moisture content was 7.1796±0.00% for mung beans waste and 31.479±0.00 for the sawdust. Ash content was 8.25±0.002% for mung beans waste and 1.070±0.001% for the sawdust. The volatile matter was 16.610±0.01%) for sawdust and 22.976±0.00% for mung beans waste.The fixed carbon content of the sawdust was (50.841±0.00%) and 61.57±0.00% for mung beans waste.The calorific value was 18.60MJ/kg for mung beans waste and 20.30MJ/kg for the sawdust. The mass of the briquette increased with an increase in biomass load, ranging from 44.1±0.01 (70% sawdust and 30% biomass) to 61.1±0.90 (100% biomass). The bulk density of the sawdust briquette increased with increase in biomass load ranging from 0.234±0.00 g/m³ (70% sawdust+ 30% biomass) to 0.421±0.007 g/m³ (100% biomass). Hardness of the sawdust briquette increased with increased in biomass load with value ranging from 366±0.57 (70% sawdust + 30% MB) to 394±0.00 (100% MB). The porosity of the briquette decreased with increased in biomass load ranging from 0.20±0.01 (100% MB) to 0.97±0.01 (30% MB + 70% sawdust). The durability of the briquettes decreased with increase in biomass load ranging from 0.89±0.00 (70% sawdust + 30% biomass) to 0.79±0.01 (100% biomass). The compressive strength of the briquettes increased from 70% sawdust + 30% biomass (2.78±0.01 N/mm²) to 30% sawdust + 70% biomass (3.42±0.38 N/mm²) before decreasing at 100% biomass (2.44±0.02 N/mm²). It can be concluded that Mung beans waste can effectively enhance the efficiency of sawdust briquettes by improving the mechanical properties.