Angélica de Cássia Oliveira Carneiro

Quality of Wood and Charcoal from Eucalyptus Clones for Ironmaster Use

Considering the wide variety of species and clones of Eucalyptus cultivated in Brazil, it is necessary to search for new information on wood properties, so that the selection of genetically superior material may be successful. The present study aimed to determine the properties of wood and charcoal from different clones of Eucalyptus spp. Six clones at the age of 7.5 years were evaluated and the samples were from a clonal, located in the city of Lassance, Minas Gerais, Brazil. Basic density, chemical composition, and higher heating value were determined. Carbonizations in a laboratory kiln were done and the levels of volatile matter, ash, and fixed carbon, higher heating value, and bulk density of the charcoal produced were determined. Evaluated genetic materials showed differences in their properties. According to research results, several properties of wood should be considered together for the selection of clones for charcoal production. However, basic density and chemical composition of wood, especially high contents of lignin and low contents of extractives, are the properties that had more influence on charcoal yield and its quality. Concerning charcoal production for steelmaking, clone 6 stood out and, conversely, clone 4 showed inferior properties to those of others.

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.

Propriedades energéticas da madeira e do carvão de paricá (Schizolobium amazonicum)

The objective of this study was to evaluate the energy potential of wood and coal of Schizolobium amazonicum (parica). The trees were collected in the region of Dom Eliseu - PA, at ages 5, 7, 9 and 11 years and sectioned in four logs of 2.7 m each. By using the thermogravimetric analysis of wood, mass loss as a function of temperature was determined. The higher calorific value was obtained according to NBR- 8633 standard. Gravimetric yield in coal and its chemical composition were also determined. There was significant effect of age and height in the log only at the temperature range from 300 to 400oC. The wood calorific value was influenced by the age of trees and the highest value was observed at the age of 5 years. The gravimetric yield and chemical composition of charcoal were not affected by the age of the trees.

Potencial energético da madeira de Eucalyptus sp. em função da idade e de diferentes materiais genéticos

The present study aimed to determine the influence of age and different genetic material of Eucalyptus sp. in wood energy production. Therefore, we evaluated three Eucalyptus sp. clones from Gerdau S/A, at four different ages: 3, 4, 5 and 7 years. Five discs were removed from each tree (0%, 25%, 50%, 75%, 100% of the trunk commercial height), and the wood basic density and calorific value were determined. Based on these values we estimated the energy m-3 amount. We observed an effect of age and genetic material for the wood density and the calorific value. Moreover, the amount of energy m-3 increased with increasing age, and the three genetic materials evaluated were significantly different between them. The GG 680 clone showed better performance for this variable, presenting at seven years 2,943 kW.h.m -³ . Note that the selection of the best genetic material must consider the wood technological characteristics, as well as their productivity and effectiveness of technical production.

Otimização da produção do carvão vegetal por meio do controle de temperaturas de carbonização

Although in recent years several studies have been done with the aim of improving the wood quality indices (basic density, chemical composition), much of the Brazilian charcoal production still occurs in kilns that have low gravimetric yield and uncontrolled emissions of polluting gases. In an attempt to change this scenario, this work was developed with the objective of evaluating the operation of a kiln-furnace system. The work also aimed to adjust carbonization control ranges according to temperature and time, taking into account the thermal degradation of wood in order to maximize the yield of charcoal. Three kilns were built, attached to a furnace for burning the gases generated during the carbonization. Control of carbonization was conducted using internal temperature, measured by an infrared temperature sensor. According to the results, controlling time and temperature during the carbonization provided average gravimetric yields of 33% charcoal, 8% semi-carbonized wood and 3% fines (particle size less than 12.7 mm). The furnace was efficient in reducing fume to the environment, working for a third time carbonization. It is concluded that the kiln-furnace system presents satisfactory production of charcoal, with low fume during carbonization.

Potencial energético da madeira de espécies oriundas de plano de manejo florestal no Estado do Rio Grande do Norte

The objective was to evaluate the energy potential of woods of species under forest management plan from Serido region in the Rio Grande do Norte state. It was used the wood species Jurema Preta, Pereiro, Marmeleiro, Catingueira, Mororo, Imburana, Jurema Branca and Mofumbo, at 20 years old, originated from the Dominga´s farm in the Caico/RN municipality. The density, the content of volatiles, the ash and fixed carbon, calorific value, elemental composition and carbon/nitrogen (C/N) and carbon/ hydrogen (C/H) analysis were carried out in the wood. Additionally, the amount of energy produced in kW.h.m-3 and kW.h.ha-1 for all species was estimated. The experiment was conducted in a completely randomized design with eight treatments (species), four replicates (sample trees), adding up to 32 sampling units. There were significant differences, at 5% significance between treatments for all variables, except for hydrogen percentage and C/H ratio. It was concluded that Mororo´s wood shows high energy potential, and along with Jurema Preta, presents higher energy generation per m3, and provides greater economy for the same productivity. The energy potential Jurema Preta wood´s stands out among the species. Pereiro´s wood stands for energy production per hectare. Marmeleiro and Jurema Branca´s woods are indicated as direct burning potential and Imburana´s wood is not recommended for power generation.

Acúmulo de matéria seca e óleo nas sementes de pinhão-manso e qualidade do óleo extraído

Objetivou-se, com o presente trabalho, avaliar o efeito do estadio de maturacao dos frutos sobre o rendimento em massa de materia seca e oleo das sementes de pinhao-manso (Jatropha curcas L.) , e sobre a qualidade do oleo extraido. Frutos de pinhao-manso foram classificados em quatro diferentes estadios de maturacao, de acordo com sua coloracao: verde, amarela, marrom-amarela e marrom. Amostras dos frutos de cada estadio foram retiradas para a determinacao do teor de agua, dimensoes principais, volume e contagem de sementes por fruto. As sementes foram extraidas para determinacao do teor de agua, dimensoes principais, volume, massa seca de mil sementes, percentual em massa de oleo e percentual de acidos graxos livres do oleo extraido. A colheita de frutos de pinhao-manso com coloracao marrom-amarelo e marrom, proporcionou maior rendimento em massa seca das sementes e em conteudo de oleo. A colheita dos frutos com coloracao marrom-amarelo alem de possibilitar bons rendimentos em oleo e em materia seca, permite a obtencao de oleo com indice de acidez menor, sendo o estadio de maturacao mais indicado para a realizacao da colheita dos frutos e sementes de pinhao-manso para fins industriais.

PROPERTIES OF PARTICLEBOARDS FABRICATED WITH EUCALYPTUS (Eucalyptus urophylla), PARICA (Schizolobium amazonicum) AND VASSOURA (Sida spp.) PARTICLES

O genero Sida pode se tornar uma fonte alternativa bastante promissora para a producao de paineis de madeira aglomerada, uma vez que e utilizado na fabricacao de cordas, em razao da qualidade de suas fibras, porem, sao inexistentes pesquisas relacionadas a producao de paineis de aglomerado, utilizando este material lignocelulosico. Neste trabalho, objetivou-se avaliar as propriedades fisicas e mecânicas de paineis aglomerados de eucalipto (Eucalyptus urophylla) e parica (Schizolobium amazonicum) em associacao com vassoura (Sida spp.). Para a producao dos paineis de aglomerado foram utilizadas misturas em 4 proporcoes (25, 50, 75 e 100%) de particulas de vassoura em associacao com particulas de eucalipto e parica, e associacao de particulas de eucalipto em associacao com parica, sendo adicionadas a essas particulas dois teores de adesivo a base de ureia-formaldeido (6% e 8%). Os ensaios fisicos e mecânicos foram realizados segundo a norma NBR/ABNT 14810-3 (ASSOCIACAO BRASILEIRA DE NORMAS TECNICAS - ABNT, 2002). Os resultados experimentais mostraram que o aumento no teor de adesivo na producao dos paineis de aglomerado contribuiu para melhorar algumas propriedades fisicas e mecânicas. Concluiu-se que o incremento de particulas de vassoura nos paineis teve efeito diferenciado em funcao das especies utilizadas. O incremento da porcentagem de particulas de vassoura aos paineis produzidos com eucalipto nao afetou a resistencia a tracao perpendicular, arrancamento de parafuso e dureza Janka. O incremento da porcentagem de particulas de vassoura aos paineis produzidos com parica nao afetou a resistencia a dureza Janka e ao arrancamento de parafuso. Os paineis produzidos com particulas de vassoura absorveram mais agua e, por consequencia, o inchamento em espessura aumentou, sendo, portanto nao recomendados para uso em ambientes com alto teor de umidade. Concluiu-se que o genero Sida, de modo geral, apresentou potencial para producao dos paineis de aglomerado.

Strength properties and dimensional stability of particleboards with different proportions of thermally treated recycled pine particles

Abstract Wood-based panels made of waste and recycled raw material are lacking of dimensional stability. The aim of this study is to evaluate the potential beneficial effect of heat treatment (HT) on the properties of particleboards produced from waste of Pinus sp. used for packaging. The wood particles were heat treated at 180°C, 200°C and 220°C after grinding, and panels were produced with incorporation of 25%, 50%, 75% and 100% HT particles. The materials served as reference were particles without HT. Mass loss at 180°C and 200°C was small but increased significantly to 10.6% at 220°C. The HT caused a partial degradation of hemicelluloses, thereby the relative lignin content increased from 29.7% to 37.8% for the HT220°C samples. Thermogravimetry revealed higher thermal stability of the HT particles. The equilibrium moisture content decreased with HT, e.g. panels with HT220°C showed 30% lower compared to the reference. Swelling of the panels was lowered by 30% (panel with 75% HT material) compared to the reference. The results with HT pine were successful in terms of dimensional stability and lower hygroscopicity; however, the panels lost some strength properties.