POTENCIAL ENERGÉTICO DE MADEIRAS NEOTROPICAIS EM PLANTIOS DE RESTAURAÇÃO FLORESTAL

Abstract

The use of wood from forests in forest restoration established in degraded areas is a great option to ensure economic and ecological maintenance. An alternative for the generation of energy would be the use of native species with timber potential in areas of sustainable forest management. It is believed that neotropical species from areas undergoing forest restoration have sufficient technological characteristics to be directed to the generation of bioenergy. Therefore, this research work aims to investigate the potential of wood from neotropical species from plantations in forest restoration for the generation of bioenergy. Woods from 12 neotropical native species were collected from an area under forest restoration destined to the Legal Reserve on the banks of the Tietê River, in the municipality of Anhembi, SP. Subsequently, the characterization of the wood of these species was carried out in terms of its physical, chemical, and energetic properties, through the determination of the basic density, X-ray densitometry, chemical components, calorific value, and energy density. Soon after, the woods were submitted to the pyrolysis process to determine the charcoal yields and later, the same analyzes performed for the wood were carried out. The woods of Myrocarpus frondosus, Poecilanthe parviflora, Handroanthus impetiginosus, Pterogyne nitens, and Hymenea courbaril presented moderate basic density, varying between 0.550 and 0.650 g cm-3. The species Croton urucurana, Guazuma ulmifolia, Jacaranda cuspidifolia, Pelthofoum dubium, Cedrela fissilis and M. frondosus had lignin contents above 30%. All species had ash contents below 2%. As there is a strong correlation between basic density and energy density, the species that stood out in the first variable also stood out in the second. By simplifying the set of variables through principal components, groups were formed that shared close values for the variables of interest for energy generation. For the generation of energy in the form of firewood, the species that stood out the most were M. frondosus, P. parviflora, P. nitens and J. cuspidifolia. For charcoal, P. parviflora and C. fissilis showed higher values of apparent density, 0.490 and 0.380 g cm-3 respectively. All materials had ash values below 2%. The charcoal of H. courbaril stood out for displaying a net calorific value of 7,047 kcal kg-1. By simplifying the charcoal dataset through two main components, four distinct groups can be observed and the species P. parviflora and H. courbaril are isolated. It is noticed that the group formed by charcoal from M. frondosus, P. nitens, and P. dubium, together with the isolated species P. parviflora, present a combination of high values for energy density, apparent density, fixed carbon content, and low ash contents. For energy use through charcoal, M. frondosus, P. nitens, P. dubium, and P. parviflora stood out. In this way, the woods of Neotropical species from forest restoration plantations have the potential to generate bioenergy, in the form of firewood and charcoal.