Paulo Fernando Trugilho

Characterization of residues from plant biomass for use in energy generation

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 calorific 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, calorific 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 calorific value and fixed carbon. The remaining residues were found to have similar energetic characteristics, with corn cob showing greater calorific value, followed by coffee plant stem, both also containing higher levels of carbon and fixed carbon. A high correlation was found of higher calorific value with volatile materials, carbon and hydrogen contents.

Melhoramento genético das propriedades do carvão vegetal de Eucalyptus

Os objetivos deste trabalho foram estimar os parâmetros fenotipicos, e genotipicos, e ganhos geneticos para as propriedades do carvao vegetal e selecionar clones de Eucalyptus, por meio de caracteristicas do carvao vegetal, visando a otimizacao da sua producao e qualidade. Foram utilizados nove clones hibridos de Eucalyptus cultivados no Municipio de Taiobeiras, Norte de Minas Gerais. O delineamento experimental utilizado foi o inteiramente casualizado, com tres repeticoes. Os parâmetros fenotipicos e geneticos foram estimados a partir dos quadrados medios das caracteristicas avaliadas no carvao vegetal. Estimou-se o ganho genetico de todas as caracteristicas que apresentaram significância. O efeito de clone foi significativo quanto ao rendimento gravimetrico do carvao, rendimento em carbono fixo e densidade basica relativa aparente do carvao. O ganho genetico previsto para o rendimento gravimetrico do carvao foi de 4,51% na selecao dos clones FGA-30 e FGA-49 e de 4,16% para o rendimento em carbono fixo na selecao dos clones FGA-30 e I-249. Para densidade basica relativa aparente, o ganho genetico foi de 0,03% na selecao dos clones FGA-49 e FGA-34.

Utilização de eucaliptos e de madeiras nativas no armazenamento da aguardente de cana-de-açúcar

The aim of this work was to evaluate different species of Eucalyptus and of native wood to make barrels for storage of sugar cane spirit. It was studied the chemical, anatomical and physical properties of the woods and made physical-chemical analyses of the sugar cane spirit storage during twelve months. The barrels made with wood of Eucalyptus presented little permeabilidade to liquids and a low dimensional estability, provoking discard of great part of them. The chemical composition of the different Eucalyptus wood showed constant polissacarydes and lignina contents but differing among extractives levels, that were higher than the oak wood. The composition of the sugar cane spirit stored in these kind of wood showed pattern according to the Brazilian law, indicating their potential use as barrels for the storage of sugar cane spirit. The native wood, also showed low dimensional instability with no leaking, constant polyssacarydes and lignina contents and higher extractive levels than oak wood. The sugar cane spirit composition after storage was also according to the law.

Comparação de métodos de determinação da densidade básica em Madeira

O presente trabalho visou o estudo comparativo de 6 metodos propostos para a determinacao da densidade basica em madeira e ainda, o efeito de 3 dimensoes dos corpos de prova nos metodos. Para tal empregou-se distintamente cerne e alburno da especie Hymenaea cobaril L. (jatoba) em corpos de provas nas dimensoes 2 x 2 x 1 com (D1), 2 x 2 x 3 com (D2) e 2 x 2 x 5 cm (D3). Os metodos analisados foram: a) metodo de imersao-baseado na variacao do peso do liquido (M1); b) o metodo de medicao direta do volume por paquimetro (M2); c) metodo de imersao-baseado na variacao do peso da amostra (M3); d) metodo de medicao direta do volume por cilindro graduado-corpo de prova imerso em areia (M4); e) metodo de maximo teor de umidade (M5) e f) metodo de medicao direta do volume for cilindro graduado-corpo de prova imperso em agua (M6). Os metodos M1, M3 e M5 foram os mais precisos, de melhores repetibilidades, iguais estatisticamente e que nao sofreram influencia das dimensoes influenciaram significativamente os metodos M2, M4 e M6, que foram os menos precisos.

Propriedades e classificação da madeira aplicadas à seleção de genótipos de Eucalyptus

The objective of this study was to classify and select superior genotypes of eucalypt based on the properties of its wood, utilizing cluster analysis, the Tochers optimization method aiming to obtain various products. Forty-four genotypes adapted to the environmental conditions of northwestern Minas Gerais were used. Physical, mechanical resistance and chemical wood characteristics were used for the classification of the materials. Cluster analysis classified the genotypes in 11 different groups with high variability or divergence among them. According to the average values of the characteristics presented by the formed groups, it was possible to define new potential clones, which will certainly provide wood of superior quality. The genotypes from groups V, VI and VIII show potential for the production of sawed wood, also facilitating the generation of natural hybrids, which may be used in future programs of genetic improvement of Eucalyptus.

ANÁLISE TERMOGRAVIMÉTRICA EM CLONES DE EUCALIPTO COMO SUBSÍDIO PARA A PRODUÇÃO DE CARVÃO VEGETAL

No Brasil, o uso da madeira, para geracao de energia, tem sido relacionado a producao de carvao, em decorrencia da demanda existente pelo produto junto ao setor siderurgico e, em sua grande maioria, sao especies do genero Eucalyptus. No entanto, em funcao das variacoes que ocorrem na qualidade da madeira do referido genero, faz-se necessario estuda-las, pois esse fato pode ocasionar consequencias negativas na qualidade e rendimento do carvao vegetal, as quais refletirao nas operacoes dos alto-fornos siderurgicos. O objetivo do presente trabalho foi estudar a qualidade da madeira de diferentes materiais geneticos de eucalipto para producao de carvao vegetal por meio da analise termogravimetrica. No estudo, considerou-se a resistencia a degradacao termica da madeira e as caracteristicas qualitativas e quantitativas do carvao. Pelos resultados, verificou-se que os maiores picos de degradacao termica ocorreram na faixa de temperatura compreendida entre 300 e 400oC; o material genetico um foi o que apresentou a menor perda de massa total e o tres foi o menos estavel, tendo esses apresentado, respectivamente, maior e menor rendimento gravimetrico em carvao vegetal; todos os materiais geneticos apresentaram, de modo satisfatorio, rendimento gravimetrico em carvao vegetal e qualidade dos mesmos.

ESTUDO DA DEGRADAÇÃO TÉRMICA DA MADEIRA DE Eucalyptus ATRAVÉS DE TERMOGRAVIMETRIA E CALORIMETRIA

RESUMO – O objetivo deste trabalho foi avaliar a degradacao termica da madeira de diferentes clones de Eucalyptus, por meio de analises termogravimetrica (TG/DTG) e de calorimetria exploratoria diferencial (DSC), estabelecendo-se suas relacoes com a producao de carvao vegetal. Foram utilizados seis clones de Eucalyptus spp. aos 7,5 anos de idade, provenientes de um teste clonal pertencente a uma empresa florestal. Foram realizadas as analises TG/DTG e DSC, sob atmosfera de gas nitrogenio. As curvas TG/DTG mostraram tres faixas de degradacao termica, atribuidas a secagem da madeira e a degradacao de hemiceluloses e celulose. Nao foi detectada faixa especifica de degradacao de lignina. As curvas DSC evidenciaram um pico endotermico entre as temperaturas de 50 e 100 oC, o que pode ser atribuido a perda de agua da madeira. A liberacao de calor iniciou-se em temperaturas acima de 275 °C, para todos os clones avaliados, sendo observados dois picos exotermicos. As analises termicas da madeira (TG/DTG e DSC) nao apresentaram variacoes expressivas entre os clones. Conclui-se que, atraves das tecnicas estudadas, e possivel identificar as principais fases das reacoes de liberacao ou absorcao de energia e perda de massa, que estao diretamente ligadas a qualidade do carvao vegetal.

Resonance and near infrared spectroscopy for evaluating dynamic wood properties

Dynamic longitudinal (L) and transversal (T) tests based on wood resonance were performed on Eucalyptus specimens measuring 410 mm × 25 mm × 25 mm to obtain the dynamic elastic modulus (EL and ET), the first resonance frequency (f1L), the loss tangent (tan δT) and the specific modulus (E′L and E′T). Such dynamic traits and the air-dry density of wood were correlated by partial least squares (PLS) regressions to the near infrared (NIR) spectra measured in the central position of the longitudinal–radial surfaces. The statistics of the validation models for E, E′ and f1L ranged from 0.72 to 0.81 while the calibrations for loss tangent presented lower r2v (0.38), but promising RPD (ratio of performance to deviation) values (1.88). The key role of chemical wood components in the NIR-based calibrations for dynamic properties of wood is discussed. The association of the NIR spectroscopy and resonance techniques appears to be a rapid, low-cost and precise way to evaluate the visco-elastic properties of woods.

Properties of biochar derived from wood and high-nutrient biomasses with the aim of agronomic and environmental benefits

Biochar production and use are part of the modern agenda to recycle wastes, and to retain nutrients, pollutants, and heavy metals in the soil and to offset some greenhouse gas emissions. Biochars from wood (eucalyptus sawdust, pine bark), sugarcane bagasse, and substances rich in nutrients (coffee husk, chicken manure) produced at 350, 450 and 750°C were characterized to identify agronomic and environmental benefits, which may enhance soil quality. Biochars derived from wood and sugarcane have greater potential for improving C storage in tropical soils due to a higher aromatic character, high C concentration, low H/C ratio, and FTIR spectra features as compared to nutrient-rich biochars. The high ash content associated with alkaline chemical species such as KHCO3 and CaCO3, verified by XRD analysis, made chicken manure and coffee husk biochars potential liming agents for remediating acidic soils. High Ca and K contents in chicken manure and coffee husk biomass can significantly replace conventional sources of K (mostly imported in Brazil) and Ca, suggesting a high agronomic value for these biochars. High-ash biochars, such as chicken manure and coffee husk, produced at low-temperatures (350 and 450°C) exhibited high CEC values, which can be considered as a potential applicable material to increase nutrient retention in soil. Therefore, the agronomic value of the biochars in this study is predominantly regulated by the nutrient richness of the biomass, but an increase in pyrolysis temperature to 750°C can strongly decrease the adsorptive capacities of chicken manure and coffee husk biochars. A diagram of the agronomic potential and environmental benefits is presented, along with some guidelines to relate biochar properties with potential agronomic and environmental uses. Based on biochar properties, research needs are identified and directions for future trials are delineated.

DEFORMAÇÕES RESIDUAIS LONGITUDINAIS DECORRENTES DE TENSÕES DE CRESCIMENTO EM EUCALIPTOS E SUAS ASSOCIAÇÕES COM OUTRAS PROPRIEDADES 1

RESUMO - Tensoes de crescimento representam um fator limitante para o uso do eucalipto de rapido crescimento como produtor de toras para serrar. A quantificacao e qualificacao dessas tensoes em arvores de Eucaliptos ainda carecem de muitas informacoes no Brasil. Assim, objetivou-se avaliar a aplicacao de um novo instrumento, o extensometro CIRAD-Foret, na medicao das deformacoes residuais longitudinais (DRL) em arvores de cinco materiais geneticos de Eucaliptos e correlaciona-las com outras caracteristicas da madeira e dimensoes das arvores. Dos resultados pode-se concluir que: i) o extensometro e simples de ser usado, rapido e confiavel para medir e identificar arvores com diferentes niveis de tensoes de crescimento; ii) a deformacao residual longitudinal (DRL), associada as tensoes de crescimento, medida com o extensometro foi em media igual a 71 µm; iii) nao foi encontrada diferenca estatistica nas DRLs medidas nas diferentes orientacoes cardeais em volta do tronco; iv) as DRLs variaram em funcao dos materiais geneticos de acordo com a analise de variância; v) em um dos materiais geneticos, no qual a DRL foi medida em duas posicoes ao longo do tronco (1,3 e 2,5 m), os valores foram semelhantes; vi) entre as varias propriedades da madeira, apenas a densidade basica foi correlacionada significativa e positivamente com a DRL quando todos os materiais geneticos foram analisados conjuntamente; vii) exceto para o fator de estabilidade (DAP/altura total) da progenie 5, as correlacoes entre as DRLs e as caracteristicas de crescimento das arvores nao foram significativas quando os materiais geneticos foram analisados isoladamente. Entretanto, quando os cinco materiais geneticos foram reunidos, apenas a altura total da arvore nao resultou em correlacao significativa com DRL; viii) a adicao de DRL as caracteristicas de crescimento das arvores permitiu que a densidade e as varias propriedades mecânicas da madeira fossem significativamente estimadas por modelos multiplos. ABSTRACT - Growth stresses are a limiting factor in the use of fast growing eucalypts for the production of sawing logs. Further studies are needed for the qualification and mensuration of these stresses in eucalypts trees in Brazil. Thus, the main objective of this work was to evaluate the application of a new instrument, CIRAD-Foret extensometer, in the measurement of the longitudinal residual strain (DRL) in standing trees of five genetic materials of eucalypts, experimentally cultivated in Aracruz-Espirito Santo, and to correlate the magnitude of such strain with other wood properties and tree dimensions. The results obtained showed that: i) the extensometer is a simple, rapid and reliable instrument to measure and identify trees with different levels of growth stresses; ii) the DRL associated to the growth stresses measured with the extensometer were in average equal to 71 µm; iii) no statistical differences were found in the DRLs measured in different cardinal orientations; iv) the DRLs varied significantly with the genetic material according to the analyses of variance; v) for clone 1, in which the DRLs were measured in two positions along the stem (1.3 m and 2.5 m), the values were similar; vi) among various wood properties, only basic density was positive and significantly correlated with the DRLs when the five genetic materials were analysed together; vii) except for the stability factor (DBH/total height) of variety 5, the correlation between DRL and the tree growth dimensions were not significant when the genetic materials were analyzed separately, however, when the five genetic materials were analyzed together, only total height of the tree did not result in significant correlation with the DRLs; viii) DRL addition to the tree growth dimensions allowed density and several wood mechanical properties to be significantly estimated by multiple models.