ABSTRACT:The use of plant residues for energy purposes is already a reality, yet in order to ensure suitability and recommend a given material as being a good energy generator, it is necessary to characterize the material through chemical analysis and determine its calorifi c value. This research aimed to analyze different residues from plant biomass, characterizing them as potential sources for energy production. For the accomplishment of this study, the following residues were used: wood processing residue (sawdust and planer shavings); coffee bean parchment and coffee plant stem; bean stem and pod; soybean stem and pod; rice husk; corn leaf, stem, straw and cob; and sugar cane straw and bagasse. For residue characterization the following analyses were done: chemical analysis, immediate chemical analysis, calorifi c value and elemental analysis. All procedures were conducted at the Laboratory of Forest Biomass Energy of the Federal University of Lavras. In general, all residues showed potential for energetic use. Rice husk was found to have higher lignin content, which is an interesting attribute as far as energy production is concerned. Its high ash content, however, led to a reduction in calorifi c value and fi xed carbon. The remaining residues were found to have similar energetic characteristics, with corn cob showing greater calorifi c value, followed by coffee plant stem, both also containing higher levels of carbon and fi xed carbon. A high correlation was found of higher calorifi c value with volatile materials, carbon and hydrogen contents.

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In this study, we investigated the ionothermal carbonization (ITC) in 1-butyl-3-methylimidazolium tetrachloroferrate, [Bmim][FeCl4], of cocoa bean shells, a raw lignocellulosic agrowaste. The beneficial inputs of this ITC approach towards mass...

Wood drying is one of various stages in the carbonization process, therefore proper monitoring is key to improving yield and obtaining quality charcoal. Prior to being subjected to carbonization by charcoal production plants and once trees have been felled, logs are piled up by the roadside or close to carbonization furnaces and left air drying for 90 days until an optimal 30% moisture content is reached. This work aims to evaluate air drying of logs from an Eucalyptus urophylla clone for carbonization use, analyzing moisture reduction over time and also the influence of log diameter and bark. Logs with and without bark were used, 6.0cm to 21.0cm in diameter, 3.60m in length, with average basic density of 0.496 g/cm 3 , obtained from a commercial stand of Eucalyptus urophylla at age 8 years. Air drying log piles were arranged outdoors in Paraopeba, Minas Gerais State, Brazil and monitoring consisted of periodic log weighing for a period of 80 days. At the end of the experiment, higher rates of moisture loss were observed in the three initial weeks. Moisture in logs without bark (54%) and with bark (50%) was close after 80 drying days, with a higher level of moisture reduction being observed for logs without bark. Bark influence on moisture loss was more pronounced in the first three weeks. Moisture reduction varied in intensity as a function of log diameter. After 80 days, the highest level of moisture reduction was observed in logs without bark: 65% for logs larger in diameter and 80% for logs smaller in diameter. As regards logs with bark, results were 56% and 75% respectively.Key words: Charcoal, log piles, moisture content. SECAGEM AO AR LIVRE DE TORAS DE UM CLONE DE Eucalyptus urophylla EMPREGADO NA CARBONIZAÇÃO RESUMO: A secagem da madeira é uma das etapas do processo de carbonização e seu controle é de grande importância no rendimento e na qualidade do carvão vegetal produzido. Nas empresas produtoras de carvão, após o corte, a madeira é empilhada nas margens das estradas ou próxima aos fornos de carbonização e é carbonizada após 90 dias de secagem ao ar livre, quando se deseja alcançar 30% de umidade. Neste trabalho, objetivou-se avaliar a secagem ao ar livre de toras de um clone de Eucalyptus urophylla empregado na produção de carvão vegetal, analisando-se a perda de umidade no tempo, influência da casca e do diâmetro das toras no processo. Foram utilizadas toras com casca e sem casca, com diâmetros variando de

RESUMO O objetivo deste trabalho foi avaliar o efeito do material genético, clones e espécies, e da classe de diâmetro nas características de crescimento, composição química, densidade básica e a estimativa de massa seca de madeira. Foram avaliados quatro clones e cinco espécies, aos quatro anos de idade, de

The objective of this study was to evaluate the potential of near-infrared (near IR) spectroscopy associated with multivariate statistics to distinguish charcoal produced from wood of planted and native forests in Brazil. Timber forest species from the Cerrado (Cedrela sp., Aspidosperma sp., Jacaranda sp., and Apuleia sp.) and Eucalyptus clones from forestry companies (Vallourec steel producer and Cenibra pulp producer) were pyrolyzed under well controlled laboratory scale conditions at the final temperatures of 300 (573,15), 500 (773,15) and 700 °C (973,15 K), respectively. Fifteen charcoals of each species were produced for each temperature leading to heighten controlled pyrolysis treatments and finally 270 charcoal samples (3 treatments × 15 repetitions × 6 materials). Principal component analysis (PCA) and partial least-squares regression (PLS-R) were carried out in the spectra recorded from charcoal specimens. Near IR spectroscopy associated with PCA was not able to differentiate the charcoals produced from native and planted woods if the 270 samples were considered in the same analysis. However, the separation of native and planted charcoal was achieved when the samples were analyzed separately by final pyrolysis temperature. Thus, the prediction of native or planted classes by PLS-R presented better performance for samples pyrolyzed at 300 °C, followed by those at 500 °C, 700 °C, and all together.

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ResumoO objetivo deste estudo foi avaliar o efeito da posição radial e temperatura final de carbonização nas propriedades químicas, físicas e mecânicas do carvão vegetal oriundo da madeira de Corymbia e Eucalyptus. Foram abatidos três indivíduos de Corymbia citriodora e dois hibridos naturais de Eucalyptus urophylla (VM04 e MN463). De cada indivíduo foi retirado um torete e o mesmo foi mecanicamente processado de modo a serem retiradas amostras em três posições radiais distintas para determinação da densidade básica e para a carbonização em três diferentes temperaturas finais. O carvão vegetal de C. citriodora apresentou maior densidade relativa aparente, teor de minerais, resistência à penetração da semiesfera de aço e tensão máxima suportada. Há uma relação direta entre a temperatura final de carbonização e os teores de carbono fixo, resistência e rigidez do carvão vegetal. Houve uma tendência de incremento da densidade relativa aparente, de resistência à penetração da semiesfera e de tensão máxima suportada do carvão vegetal no sentido medula-câmbio. Houve ainda uma tendência do carvão produzido com madeira mais próxima à medula apresentar maior teor de minerais.Palavras-chave: variação radial, carvão, propriedades físicas, químicas e mecânicas. AbstractThe objective of this study was to evaluate the effect of radial position and final carbonization temperature on the chemical, physical and mechanical properties of charcoal from wood of Corymbia and Eucalyptus. Three individuals of Corymbia citriodora and two natural hybrids of Eucalyptus urophylla (VM04 and MN463) were cut. One short piece was removed from each individual and it was mechanically processed, so that the samples were removed at three different radial positions for the determination of basic density and for carbonization at three different final temperatures. Charcoal from C. citriodora had higher apparent relative density; mineral content; penetration resistance of the semi-sphere of steel and maximun tension supported. There is a direct relationship between final carbonization temperature and the contents of fixed carbon, resistance and charcoal stiffness. There was an increasing trend in apparent relative density, penetration resistance of the semi-sphere and charcoal maximun tension supported from the pith to the cambium. There was still a tendency towards a higher mineral content for the charcoal produced with the wood closest to the pith. INTRODUÇÃOO Brasil, na atualidade, é o maior produtor e consumidor de carvão vegetal do mundo (FAO, 2014). Isso se deve ao fato do país ser um dos poucos a utilizar o carvão vegetal para fins industriais como, por exemplo, a termorredução de minério de ferro. Grande parte da produção nacional do ferro-gusa produzido utiliza o carvão vegetal como termorredutor, enquanto que nos demais países produtores utiliza-se quase que exclusivamente o carvão mineral para o mesmo objetivo.As funções vitais do carvão no processo de termorredução do minério de ferro são basicamente: fornecer energia na forma de calor, rec...