Non-conventional biomasses for briquette manufacturing: Densification parameters and quality

The objective of this study was to produce and evaluate briquettes from residues of corn crops and from its association with cotton crop residues, rice husk or elephant grass for energetic use. Data on moisture, immediate chemical analysis, bulk density, higher calorific value (HCV), energetic density, volumetric expansion and mechanical strength were used to compare the treatments. Biomass was densified at 125ºC under 15 MPa of pressure for 8 minutes. HCV results were similar for all treatments. The immediate chemical analysis showed high VC and FCC for all treatments. The highest AC was observed in briquets with 20% of rice husk (4.22%) and the lowest in briquets from corn crop residues (2.67%). The apparent density of briquets ranged from 0.96 to 1.10 t.m-3 and the energetic density from 17.53 and 20.27 GJ.m-3. All treatments delivered moderate volumetric expansion, with a maximum of 14.5% by corn crop residue briquets. Water absorptions were similar for all treatments. Mechanical strength by diametrical compression revealed desirable behavior by undefined breaking points. Data demonstrate the energetic potential of solid biofuels produced by the densification of corn crop residues, as well as their mixtures in different proportions with cotton crop residues, rice husk and Elephant grass.