Caracterização anatômica, secagem e carbonização da madeira de clones de Eucalyptus e de espécies do Cerrado

Abstract

The dimensional changes of wood are a matter of debate among researchers, since this phenomenon directly affects the wood uses. For the steel industry, for example, it is necessary that charcoal present among others proprieties a high mechanical strength and adequate size. It is known that the wood anatomy directly affects theses two phenomena, both drying (wood permeability, vessel frequency and tyloses etc.) as for carbonization (proportion and dimensions of tissue, especially the fibers). The present research aimed to characterize anatomically some species of the Brazilian Cerrado and Eucalyptus clones, observe and measure behavior of the wood during desorption and absorption curves, and carbonize, the same samples that were drying, measuring the yield and behavior of the charcoal in relation to the shrinkage tangential, radial and longitudinal. Anatomical results were very similar, there is no discrepancy in the quantitative values of the anatomical elements, both for species from Cerrado as for Eucalyptus clones with exception of vessel frequency, width and height of the rays. The shrinkage of wood were quite marked timber showing correlation with the density and the charcoal yield was likely influenced by the wood chemical compositions. The results showed that the presence of wood shrinkage above fiber saturation point indicates the presence of collapsed cells and as direct consequences cracks and splitting on charcoal