Avaliação das propriedades físico-mecânicas e energéticas de briquetes produzidos a partir da serradura de Julbernardia globiflora (messassa encarnada)

Abstract

The timber industry is characterized by producing large amounts of waste, such as sawdust, in wood processing. This waste, if deposited in inappropriate places, can cause serious damage to the environment. Given this scenario, it is necessary to establish alternatives that aim to mitigate the effects of sawdust, with briquetting being one alternative. In this context, the present work aims to evaluate the physical-mechanical and energetic properties of briquettes produced from Julbernardia globiflora sawdust. To achieve this objective, 48 sawdust briquettes were produced from heartwood, sapwood and a mixture (heartwood + sapwood), in a laboratory briquette machine using sawdust with a moisture content of 10%, particle size of less than 2 mm, temperature of 120, 130, 140 and 150°C, pressure of 12 and 15 Mpa, compaction time of 3 minutes and cooling time of 30 minutes. After production, the briquettes were placed in the climate chamber for a period of 30 days, and then subjected to determination of apparent density and tensile strength testing by diametrical compression in a universal testing machine. The results show that the ash content of heartwood, sapwood and mixed sawdust was 2.63; 2.60 and 2.62% respectively. The heartwood briquettes presented a higher apparent density when compared to the sapwood and mixture briquettes, however the sapwood briquettes presented a higher compressive strength. Furthermore, the wood region had no statistically significant effect on ash content, apparent density and mechanical strength and, similarly, there were no statistically significant differences in the means of apparent density and mechanical strength for the temperatures and pressures considered, with the exception the mechanical strength of the heartwood briquettes, which were significantly influenced by the compaction temperature. It is concluded that the quality factors inherent to the wood and the briquetting process tested in this study had no significant effect on the quality of the briquettes, with the exception of the compaction temperature, which significantly influenced the mechanical strength of the briquettes.