Carbonization gravimetric yield and qualitative characterization of charcoal from hybrid <i>Corymbia</i> spp clones for industrial use

Abstract

This research aimed to evaluate the carbonization gravimetric yields and qualitative characteristics of the charcoal of hybrid clones obtained from the crossings of Corymbia species and to identify the most suitable for the steel industry. We used six clones, at six years and five months of age, sampling five trees of each genetic material. The laboratory carbonizations consisted of a final temperature of 450°C, a heating rate of 100°C.h^-1, and a residence time of 30 minutes. We determined the carbonization gravimetric yields when compared to dry wood. The charcoal produced was qualified considering the proximate chemical analysis, superior calorific value, energy density, specific wood consumption, and energy efficiency. We organized the experiment in a completely randomized design with five replicates (trees). The multivariate principal component analysis determined the variance of the normalized vectors, considering the charcoal characteristics evaluated. The results indicated a high potential for the use of Corymbia genetic materials for energy purposes, especially for producing charcoal for the steel industry. Clone 1 was prominent for producing charcoal and firewood, given its higher apparent and energetic densities, fixed carbon content and yield, and lower specific wood consumption per ton of charcoal produced. Clones 2 and 4 most distinguished themselves from the others due to higher ash content and higher specific wood consumption, respectively. The use of Corymbia hybrid clones for producing charcoal may be a good alternative due to its rapid growth and wood and charcoal characteristics similar to those of other species that are already used for energy purposes.