Avaliação De Três Madeiras Nativas Do Cerrado Goiano Visando À Utilização Energética

Abstract

Estudos que visem ampliar o conhecimento das madeiras oriundas do cerrado podem contribuir com o correto manejo das espécies. O objetivo deste estudo foi avaliar a qualidade da madeira e do carvão vegetal de três espécies do cerrado (Tachigali vulgaris, Myracrodruon urundeuva e Amburana cearensis) para fins energéticos. Foram amostradas duas árvores por espécie e, destas, foram retirados discos da base, a 25, 50, 75 e 100% da altura total. Para a madeira, determinou-se longitudinalmente a densidade básica, composição química, estoque de carbono, poderes caloríficos superior (PCS) e inferior (PCI) e densidade energética. As carbonizações da madeira foram realizadas em forno elétrico, com temperatura final de 450 ºC e taxa de aquecimento de 1,67 ºC.min-1. A posição longitudinal de amostragem não influenciou a densidade da madeira. A madeira de M. urundeuva apresentou maior densidade básica e PCS, bem como menor teor de materiais voláteis. O carvão da espécie T. vulgaris apresentou a menor densidade aparente (298 kg.m-3) e baixo teor de cinzas (1,14%), porém elevado teor de carbono fixo e PCS. O carvão vegetal da espécie M. urundeuva se destacou com elevada densidade relativa aparente (475 kg.m-3). A ordem das melhores espécies é: M. urundeuva, A. cearensis e T. vulgaris. Palavras-chave: energia renovável; espécies nativas; potencial energético; qualidade do carvão. ASSESSMENT OF THREE NATIVE WOODS FROM CERRADO OF GOIÁS FOR THE ENERGY PURPOSES ABSTRACT: Studies aimed at expanding the knowledge of woods from cerrado can contribute to the correct management of the species. The aim of this study was to evaluate the quality of wood and charcoal of three species from cerrado (Tachigali vulgaris, Myracrodruon urundeuva, and Amburana cearensis) for energy purposes. Two trees per species were sampled and, from these, disks were removed from the base, at 25, 50, 75, and 100% of the total height. For wood, the properties basic density, chemical analysis, carbon stock, higher (HHV) and lower (LHV) heating values were determined longitudinally. Carbonizations were carried out in a muffle furnace with a final temperature of 450 ºC and heating rate of 1.67 ºC.min-1. There was no effect of longitudinal position under the wood basic density. Myracrodruon urundeuva wood had the highest basic density and HHV, as well as the lowest content of volatile matters. The Tachigali vulgaris charcoal had the lowest bulk density (298 kg.m-3) and low ash content (1.14%), but a high content of fixed carbon and HHV. Charcoal of the species M. urundeuva stood out with high apparent relative density (475 kg.m-3). The order of the best species is M. urundeuva, A. cearensis, and T. vulgaris. Keywords: renewable energy; native species; energy potential; charcoal quality.

Wood quality of Astronium fraxinifolium and Enterolobium gummiferum for charcoal production

“…This same tendency was observed in other studies [9,18,24]. All values were consistent with the literature for charcoal from Cerrado species, ranging from 27.94 to 33.36 MJ kg − 1 [11,24,55], and from the Eucalyptus genus, from 29.29 to 31.96 MJ kg − 1 [35,47,68].…”

“…A. fraxinifolium, for instance, can be highlighted for all carbonization yields and charcoal productivity per volume of wood as its wood has a higher basic density and higher heating value than E. gummiferum. The average values for charcoal and xed carbon yields were consistent with the literature for charcoal from Cerrado species produced at 450 ºC -ranging from 24.87 to 35.34% for gravimetric yield, and 23.26 to 26.54% for xed carbon yield [24,55,64]. However, only the charcoal of A. fraxinifolium had a similar gravimetric yield with the Eucalyptus genus, from 28.58 to 37.62% [14,15].…”

“…There was a higher concentration of carbon in charcoal due to the increase in the nal carbonization temperature since the percentage of xed carbon has a negative correlation with the content of volatile materials [56]. Similar results were observed in the literature for charcoal produced at the nal carbonization temperature of 450 ºC, such as 24.72% for Amburana cearensis, native to the Cerrado [55], and 24% for the clone of E. urophylla x E. camaldulensis, used for energy purposes [47].…”

“…A study by Barcellos [11] indicated that the nal carbonization temperature did not in uence the ash content of charcoal, and its values for Cerrado species -such as Qualea grandi ora, 5.66%, Bowdichia virgiloides, 5.26%, and Magonia pubencens, 5.22% -were similar to those for A. fraxinifolium. The values for E. gummiferum were similar to those for Tachigali vulgaris, 1.14% [55], and for the clone of E. urophylla x E. grandis, 1.16% [14].…”

Fiber quality and wood basic density of species of the Savannah for productive purposes

“…The results for basic density were consistent with those described in the literature for Savannah species, which range from 200 to 845 kg m -3 (Vale et al, 2002;Silva et al, 2015;Siqueira et al, 2020), and similar to those presented for E. gummiferum (620 kg m -3 ), Eriotheca gracilipes (360 kg m -3 ), P. reticulata (750 kg m -3 ) and A. fraxinifolium (610 kg m -3 ) (Vale et al, 2002;Testoni et al, 2009;Oliveira, 2014). Besides, WDB values close to 659 kg m -3 were reported for different species from the Cerrado of Minas Gerais (Oliveira et al, 2021), the same region as the trees collected in this study.…”