Effect of binder type, binder concentration and compacting pressure on some physical properties of carbonized corncob briquette

Biomass fuel properties determine the choice of agricultural waste to be used in production of briquette for industrial and domestic usage. Compaction of these agro-wastes would add more values to their bulk handling, conveyance and storage properties. This work determined the effect of different binders with varying concentrations and applied die pressures on some physical properties of briquette from carbonized corncob. Cassava starch, corn starch and gelatine at three different concentrations of 10, 20 and 30% wt/wt were used as binders in the production of the briquettes at the predetermined compacting pressure levels of 50, 100, and 150 kPa using Hydraulic Press. A charcoal kiln and a punch and die were fabricated for carbonization and facilitation of the compaction of this corncob into briquettes. Physical properties such as moisture content, density and compressive strength were determined using standard procedures. The results showed that the moisture content ranged between 4.43 and 7.62% (db), relaxed density of the briquettes produced were found in range of 729 to 987 kg/m3 and compressive strength ranged from 1.02 and 8.32 MPa. Both show technological advantage and a suitable situation for material package, storage and transportation. For all the three factors investigated, variables with cassava binder at concentration of 30% and compaction pressure of 150 kPa exhibited the most positive attributes than other variables. The higher the binder concentration and compacting pressure, the better the briquettes and this results in higher quality briquettes for both storage and transportation. In conclusion, high quality and storable briquettes can be produced from the blend of carbonized corncobs and cassava starch, corn starch and gelatine. This is because the relaxed density and compressive strength of the briquettes produced are adequate; besides, the length of time or service life of the stored briquettes proved acceptable stability after some months of storage.