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Resumo -O objetivo desse trabalho foi analisar a qualidade e os rendimentos do carvão vegetal de um clone híbrido de Eucalyptus grandis x Eucalyptus urophylla, denominado comercialmente de GG100 para uso siderúrgico, em diferentes idades, espaçamentos e locais de plantio. A madeira foi carbonizada em um forno elétrico laboratorial (mufla), a uma taxa de aquecimento de 1,67 ºC min -1 e temperatura final de 450 ºC, permanecendo estabilizada por 30 min. Foram determinados os rendimentos gravimétricos em carvão vegetal, líquido pirolenhoso, gases não condensáveis e em alcatrão insolúvel, a composição química imediata e elementar, a densidade relativa aparente e o poder calorífico superior do carvão vegetal. De maneira geral, o carvão vegetal avaliado pode ser considerado homogêneo quanto aos aspectos físicos e químicos e pode ser utilizado para fins siderúrgicos. A densidade relativa aparente permitiu a diferenciação das amostras de carvão vegetal produzido na mesma condição de pirólise. Os resultados obtidos sugerem que a densidade do carvão vegetal é altamente influenciada pela madeira de origem. Observou-se que maiores valores de poder calorífico superior estão relacionados positivamente com o teor de carbono e negativamente com os teores de oxigênio, hidrogênio e nitrogênio e com o rendimento gravimétrico em carvão vegetal. Quality and yield of the charcoal from an Eucalyptus grandis x Eucalyptus urophylla hybrid cloneAbstract -This research aimed to analyze the quality and yields of the charcoal of a Eucalyptus grandis x Eucalyptus urophylla hybrid clone commercially named GG100 for use in iron industry at different ages, plantation sites and spacing. The wood was carbonized in a laboratorial electric furnace (muffle furnace) at a heating rate of 1.67 ºC min -1 until the final temperature of 450 ºC, remaining stabilized for 30 min. The gravimetric yield in charcoal, pyroligneous extract, non condensable gases and insoluble tar, proximate and elemental chemical composition, relative apparent density and higher heating value of the charcoal were determined. In general, the charcoal evaluated may be considered homogeneous based on chemical and physical aspects and can be used in the steel sector. The apparent relative density allowed the charcoal samples differentiation produced by the same pyrolysis condition. The results obtained suggest that the density of the charcoal is highly influenced by the wood origin. It was observed that higher values of higher heating values are positively related with carbon content and negatively related with oxygen, hydrogen and nitrogen contents and with gravimetric yield in charcoal.

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The use of fast-growing trees is a good economic strategy for charcoal production. Wood with adequate chemical and physical properties generally is positively correlated with charcoal quality. The objective of this research was to evaluate wood quality from fast-growing hybrids for charcoal production. Three Corymbia citriodora x Corymbia torelliana and four Corymba torelliana x Corymba citriodora hybrid clones were evaluated. Parameters used to evaluate wood quality were wood basic density, elemental and structural chemical composition, energy efficiency and thermogravimetric analysis and the parameters evaluated for charcoal quality were apparent relative density, gravimetric yield, high heating value, proximate analysis and energy efficiency. All clones had wood basic density superior than 0,5 g cm-3 and ash inferior than 1%, which are desirable for a good quality of charcoal. Lignin content did not differ among clones with an average less than the 28% recommended for energetic use. Although clones differed in wood parameters, as dry matter, high heating value, energy density, total extractives, holocellulose content, it did not reflect in charcoal quality differences. Wood from all clones had equal and satisfying high heating value of charcoal and energy efficiency quality for charcoal production and differed in apparent relative density and ash content.