Evaluation of Selected Physical and Thermal Properties of Briquette Hardwood Biomass Biofuel

Hardwood sawdust derived from primary wood processing was used to make adhesive-free briquettes in a hydraulic piston laboratory machine. For this purpose, 40 g of sawdust was used, and the conditions of the briquetting process were 5 min of pressing at 20 MPa and 50 °C. The results varied as follows: moisture (5.1 to 8.8%), density (1056.2 to 1208.8 kg m −3 ), volumetric expansion (3.3 to 38.9%), compressive strength (10.3 to 98.6 N mm −1 ), impact resistance index (46.6 to 200%), ash (1.2 to 3.9%), volatile matter (79.6 to 90.9%), fixed carbon (7.8 to 16.6%), and calorific value (19.2 to 21.2 MJ kg −1 ). In general, significant differences ( p < 0.05) were found in the results obtained. The density of the briquettes produced was greater than 1000 kg m −3 . It was observed that the higher the density of the briquettes and the lower their volumetric expansión were, the higher the breaking force and the higher the impact resistance index were. Ash values were relatively high, and the briquettes did not meet international quality standards but they could be used locally as a source of heat energy. Finally, the physical, mechanical, and energetic evaluation of the briquettes made at the laboratory level indicates that this lignocellulosic residue can be used for densification at an industrial level.