Physical and combustible properties of briquettes produced from a combination of groundnut shell, rice husk, sawdust and wastepaper using starch as a binder
This study investigated the use of agro-wastes for the production of briquettes. Briquettes were produced from a combination of groundnut shell, rice husk, sawdust and wastepaper using the 20:70:10, 30:60:10, 40:50:10, 50:40:10, 60:30:10 and 70:20:10 ratio. The feedstock of each blend was fed into a square mould [60mm] and screw-pressed at 20 MPa in a dwelling time of 60 seconds. Moisture content, density and combustion characteristics (ignition time and calorific value) of the briquettes were determined. Data obtained were analysed using appropriate statistical tools. The moisture content of all the briquettes ranged between 8 to 15%. The briquettes density was in the range of 800 to 900 kg.m−3, while the calorific value ranged from 0.03 to 0.19 and 0.02 to 0.27 MJkg−1 for Saw dust-rice husk- paper (SRP) and groundnut shell-saw dust-paper (GSP) briquettes. The quality of the briquettes in terms of density and burning time showed that 20% sawdust: 70% rice husk: 10% paper combination had a higher relaxed density of 387.4kg/m3, while on the basis of moisture content and ignition time, 70% sawdust: 20% rice husk: 10% paper combination had the least moisture content and ignition time of 16.7% and 18seconds, respectively. RSP had higher calorific value, lower ignition time, but less durability than GSP. However, the compressed and relaxed densities of SRP and GSP briquettes were significantly difference (p<0.05). The durability of the briquettes improved with increased starch proportion. It can be concluded that production of SRP and GSP briquettes is an effective and efficient agricultural waste disposal technique.
Keywords: Agro-residues, briquettes, physical, mechanical, biomass, waste