Análise do impacto da implementação das estratégias do desenvolvimento rural no distrito de Boane

Abstract

The present work has the general objective of evaluating the behavior of the physical- mechanical and energetic properties of Brachystegia spiciformis sawdust briquettes. To achieve this objective, 48 Brachystegia spiciformis sawdust briquettes were produced using sawdust from three regions of the wood: heartwood, sapwood and a mixture (heartwood + sapwood), with a moisture content of 10%, in a laboratory briquette machine with a temperature ranging from 120°C to 150°C, pressure of 12 MPa, and pressing time of 2 and 3 minutes. After curing for a period of 7 days, the briquettes were placed in the acclimatization chamber to reach a moisture content of 12%. They were then subjected to determination of apparent density and tensile strength on diametrical compression in a universal testing machine. The results indicate that the produced briquettes were composed of particles smaller than 2 mm and the ash content of the material varied between 2.67% and 3.04%. The apparent density ranged from 0.866 g/cm3 to 0.998 g/cm3, where the heartwood briquettes presented a higher apparent density when compared to the sapwood and mixture briquettes. The ultimate compressive strength was from 2,416.03 N to 4,113.00 N, with the highest values of the ultimate compressive strength observed for briquettes produced from sawdust from the sapwood region. The conclusions indicate that the wood region significantly influenced both the apparent density and the ultimate compressive strength of the briquettes. Pressing temperature also had a positive impact on mechanical properties, and in most cases apparent density increased with increasing temperature. Furthermore, the pressing time contributed to an increase in the ultimate compressive strength. It was recommended that in-depth research be carried out on the influence of pressing temperature on the physical-mechanical and energetic properties of briquettes, with more samples and repetitions, in addition to testing sawdust from other native species.