Abstract This work aimed to evaluate the energy quality of wood and charcoal obtained from the stem and root of the genus Eucalyptus spp. From the wood, the physical, chemical and energetic properties were evaluated. For the charcoal produced in ovens of the carbonization furnaces model in the industry and produced in a muffle furnace, the physical, chemical and energetic properties were evaluated. Based on the analysis of technological properties, wood from the root has higher basic density (731.45 kg m-3) and lignin content (26.44%), however, the fixed carbon content and higher calorific value of the root (17.54% and 4547.75 kcal kg-1) were lower than for the stem wood (21.36% and 4730.82 kcal kg-1). It is recommended to use the wood from the root, both for direct burning and for the production of charcoal. The charcoal obtained in the industry, compared to that produced in muffle, presented higher energy quality.

A madeira, quando exposta a condições de estresse, como no caso de um gradiente de temperatura, pode levar a estrutura de uma determinada instalação ao desmoronamento. A taxa na qual a madeira se converte em carvão é determinante, em função da redução da seção resistente. A presente investigação teve como objetivo avaliar o comportamento termomecânico da madeira de Corymbia citriodora submetida a gradientes de temperatura e diferentes tempos de exposição, com diferentes tratamentos (Verniz e CCB), com o intuito de minimizar o processo de carbonização. No que diz respeito aos ensaios mecânicos, pode-se afirmar que o aumento da temperatura de carbonização e do tempo de exposição das amostras ocasionou um decréscimo da resistência à compressão paralelamente às fibras do material, ocasionado fragilidade de carregamento. Os tratamentos testados (CCB e Verniz) não apresentaram resultados satisfatórios no que diz respeito ao retardo da combustão, não sendo, portanto, recomendáveis para esses fins.

Wood exposed to stress conditions, such as temperature gradients, may lead to collapse of installation structure. The rate at which wood becomes charcoal is crucial because of the reduction of the resistant section. This research aimed to evaluate the thermo-mechanical behavior of Corymbia citriodora wood subjected to temperature gradients and different exposure times, under different treatments (Varnish and CCB), in order to minimize the carbonization process. With respect to mechanical tests, it is possible to affirm that the increase in carbonization temperature and time of exposure of the samples resulted in a decrease in the compression strength parallel to the fibers of the material, causing brittleness. The treatments (Varnish and CCB) tested did not present satisfactory results with respect to combustion delay; therefore, they are not recommended for such purposes.

Objetivou-se avaliar a resistência de aglomerados confeccionados com madeira de Acacia mangium Willd. colada com adesivo à base de ureia-formaldeído e taninos a organismos xilófagos. Os painéis foram produzidos com 40 × 40 × 1,27 cm (largura × comprimento × espessura); ao adesivo, foram adicionados 10, 20 e 30% de taninos, sendo empregadas quatro razões de compactação (1,39; 1,55; 1,73 e 2,00). Nos ensaios com fungos e térmitas, utilizaram‑se amostras de 2,50 × 2,50 × 1,27 cm (largura × comprimento × espessura). Empregaram-se os fungos Gloeophyllum trabeum e Trametes versicolor (12 semanas de ensaio) e o térmita Nasutitermes sp. (45 dias de ensaio). Para o Gloeophyllum trabeum, os painéis com maior proporção de taninos e razão de compactação foram mais eficientes. Para o Trametes versicolor, não houve diferença entre os adesivos e razões de compactação utilizados. O Gloeophyllum causou maior perda de massa que o Trametes. Os térmitas consumiram completamente as amostras.

This study aimed to evaluate the resistance of particleboards made of Acacia mangium Willd. wood, bonded with urea-formaldehyde and tannins as adhesive, against xylophagous organisms. Panels of 40 × 40 × 1.27 cm (width x length x thickness) were produced; 10, 20 and 30% of tannins were added to the adhesive; four compaction ratios (1.39; 1.55; 1.73 and 2.00) were employed. Samples of 2.50 × 2.50 × 1.27 cm (width x length x thickness) were used in the tests with fungi and termites. Gloeophyllum trabeum and Trametes versicolor (12 weeks) fungi and Nasutitermes sp. (45 days) termites were employed in the tests. Panels with the highest compaction ratio and proportion of tannins provided the most effective resistance to Gloeophyllum trabeum. No difference between the adhesives and compaction ratios was observed for Trametes versicolor. Gloeophyllum trabeum caused greater mass loss than Trametes versicolor. The samples were completely consumed by the termites.