Jordão Cabral Moulin

ENERGY ESTIMATE AND CARBON STOCK IN SHORT-ROTATION EUCALYPTUS STANDS

A utilizacao da biomassa como fonte de energia alternativa tem obtido destaque por suas caracteristicas energeticas, contribuicao ambiental e por ser fonte de energia renovavel em curto periodo de producao. O trabalho objetivou avaliar a producao da biomassa e sequestro de carbono de eucalipto em diferentes condicoes de crescimento. Foram determinadas a densidade basica da madeira, volume individual com e sem casca, biomassa seca, carbono acumulado, dioxido de carbono assimilado e estimativa energetica dos componentes da parte aerea de dois clones do hibrido de E. grandis x E. urophylla aos 6 e 12 meses de idade, em diferentes espacamentos e provenientes de duas areas, uma irrigada e outra nao irrigada. Os maiores valores de biomassa seca e massa de carbono foram provenientes dos clones nos espacamentos mais adensados e regiao irrigada. O efeito da irrigacao foi significativo nas variaveis estudadas apenas nos clones com 12 meses. A quantidade de CO2 assimilada no fuste, folha e galho foram maiores nos espacamentos mais amplos e regiao irrigada dos clones com 12 meses. A estimativa energetica do fuste aumentou com a ampliacao do espacamento. Entre os componentes arboreos, a casca sofreu menor influencia dos espacamentos e irrigacao.

EFEITO DO ESPAÇAMENTO, DA IDADE E DA IRRIGAÇÃO NOS COMPONENTES QUÍMICOS DA MADEIRA DE EUCALIPTO

The objective of this study was to evaluate the influence of age, irrigation and spacing on the chemical composition of eucalyptus wood. The materials used were two clones of Eucalyptus grandis x Eucalyptus urophylla, ages of 6 and 12 months, from planting in two regions, one irrigated and the other not irrigated, with spacings of 3 x 0.5; 1.5 x 2; 3 x 1; 3 x 2; and 3 x 3 meters. In the chemical analysis of the wood, a sampling was conducted composed of six discs obtained along the tree trunk. At the end of this study, it was possible to notice the influence of age, spacing and irrigation in the chemical composition of the wood, and that the content of holocellulose did not follow trend pattern, with different results for each treatment. Higher values of extractives content occurred in non-irrigated clones and aged six months, with no influence of spacing. The major results of lignin content were obtained in greater spacings, although results tendency of lignin content was not seen for age and irrigated treatment. The ash content was higher at the age of six months and there was no results tendency for different spacings and regions.

Tensão de Crescimento no Lenho de Eucalyptus benthamii e sua Relação com Características Dendrométricas em Diferentes Espaçamentos

The aim of this study was to evaluate the influence of planting eucalyptus wood with respect to its dendrometric characteristics and longitudinal residual strain (LRS) of the wood, and the relationships between these variables. The material used was Eucalyptus benthamii at five years of age in 2×3, 3×3, 3×4 and 4×4 m spacing. The projection of the crown was determined by measuring eight spokes with variable angles, and maps of crown distribution and projection were prepared. Measurements of LRS were taken 1.30 m above the ground in the four cardinal directions in living trees, with the aid of strain meters (Growth Strain Gauge) by the CIRAD-Foret method. There was great variability in the results of the growth variables and levels of growth stresses for different spacing. The lowest average values of LRS were observed in the south direction, and increased spacing did not significantly alter the LRS values. Correlations between LRS and growth variables were only found with maximum LRS values ​for each tree.

Influência de compostos de boro nas propriedades físicas da madeira de Eucalyptus sp.

A madeira quando em uso tem se mostrado susceptível ao ataque de besouros e cupins, sendo tal ataque economicamente prejudicial ao homem. E, para impedir tal degradação indesejável, atualmente faz-se do uso de diversos preservantes químicos, os quais se destacam os compostos de boro. Desse modo, o objetivo desta pesquisa foi identificar a influência dos compostos de boro na densidade básica e contração da madeira de Eucalyptus sp. e, a eficiência do tratamento preservante. Foram usados 160 corpos-de-prova com dimensões de 2 x 2 x 5 cm, provenientes de resíduos madeireiros, onde 80 amostras foram tratadas com o preservante e outros 80 não receberam tratamento. Após o tratamento de impregnação à vácuo, realizou-se o teste qualitativo para avaliar a penetração do preservante na madeira tratada, bem como os ensaios de densidade e contração nas amostras com ou sem preservante. Os resultados indicaram que a maior penetração na madeira tratada com compostos de boro foi a nível parcial irregular e, que o tratamento preservante aumentou significativamente a densidade básica da madeira tratada, em relação a não tratada. E, os valores médios de contração total na madeira tratada foram inferiores em 17,5%, 14,8% e 15,5%, para contração tangencial, radial e volumétrica, respectivamente, em relação a madeira não tratada. Desse modo, observou-se que o boro afetou significativamente as propriedades físicas, analisadas, da madeira. Palavras-chave: Contração; Ácido bórico; Densidade básica; Tratamento preservante;

Effect of Spacing, Age and Irrigation on the Volume and Basic Density in Eucalyptus

This study aimed to evaluate the influence of age, irrigation and spacing, on the volume and basic density of Eucalyptus wood. We used two clones of Eucalyptus grandis × Eucalyptus urophylla with age of six and twelve months, sowed in two regions, one irrigated and other unirrigated, with spacing of 3×0.5, 1.5×2, 3×1, 3×2 and 3×3 m. The volume was estimated according to the method of Smalian as well as the weighted density. The larger volume of wood per hectare values were obtained in the close spacing and irrigated region. Wider spacing showed higher specific gravity values timber for clone A; however, clone B didn’t change with spacing. The comparison of average density values for the clones in irrigated and non-irrigated areas, showed similar results in most studied spacings.

Relation Between Dendrometric Variables and Growth Stress in Eucalyptus

The objective of this study was to identify eucalyptus clones for the production of sawed timber based on dendrometric variables and longitudinal residual deformation (LRD), analyzing the correlation between these characteristics. 20 Eucalyptus grandis x Eucalyptus urophylla clones with 13 years of age were analyzed. The crown size, diameter at breast height (DBH) and bark thickness were measured. There was a significant difference between the clones for DBH, LRD and bark thickness. There was no significant correlation between DBH and DRL. The correlation was significant between DBH and crown size, its being possible to affirm that crown size affects the diametrical growth of trees. DBH and bark thickness were also significantly correlated, in so far as trees with a wider diameter possess thicker bark. It was possible to select clones with better potential for sawed timber production, that is to say, elevated DBH with a reduced LRD.

EFFECT OF EXTRACTIVES AND CARBONIZATION TEMPERATURE ON ENERGY CHARACTERISTICS OF WOOD WASTE IN AMAZON RAINFOREST

The objective of this study was to evaluate the effect of extractives soluble in hot water, besides final carbonization temperatures, on the gravimetric yield and properties of charcoal for waste of three native forest species from the Amazon region. Waste cuttings of Ipé, Grapia and Maçaranduba species, from the machine processing for joinery of a company in the State of Pará, were used. Carbonization was carried out in an adapted electric furnace with a heating rate of 1.67°C min-1 and final temperatures of 500, 600 and 700°C. The waste was carbonized fresh after extraction in hot water to remove extractives. Gravimetric yields were analyzed, as well as chemical features and high heating value. In the evaluation of the experiment, arranged in a factorial scheme with three factors (species x temperature x material with and without extraction), and Principal Component Analysis used too. The presence of extractives (soluble in hot water) from wood waste had little influence on the gravimetric yield and immediate chemical composition of charcoal; however, it showed a greater high heating value and lower contents of hydrogen and nitrogen. The increase in the final carbonization temperature reduced the gravimetric yield in charcoal, the content of volatile materials and hydrogen, with a higher content of fixed carbon, carbon and high heating value. The treatments with the best energy characteristics were obtained from Ipé and Maçaranduba charcoals with extractives produced at 600°C, in addition to Ipê and Maçaranduba charcoals with and without extractives obtained at 700°C. EFEITO DOS EXTRATIVOS E TEMPERATURA DE CARBONIZAÇÃO NAS CARACTERÍSTICAS ENERGÉTICAS DE RESÍDUOS MADEIREIROS DA AMAZÔNIA RESUMO: O objetivo foi avaliar o efeito dos extrativos solúveis em água quente e temperatura final de carbonização no rendimento gravimétrico e propriedades do carvão vegetal em resíduos de três espécies florestais nativas, provenientes da região amazônica. Foram utilizados resíduos de aparas das espécies de ipê, garapa e maçaranduba, provenientes do processamento de usinagem da marcenaria de uma empresa do estado do Pará. As carbonizações foram realizadas em forno elétrico adaptado utilizando uma taxa de aquecimento de 1,67°C min-1 e temperaturas finais de 500, 600 e 700oC. Os resíduos foram carbonizados in natura e após extração em água quente para remoção dos extrativos. Foram analisados os rendimentos gravimétricos, as análises químicas e o poder calorífico superior. A presença de extrativos solúveis em água quente dos resíduos das madeiras pouco influenciaram no rendimento gravimétrico e na composição química imediata do carvão vegetal, contudo apresentou maior poder calorífico superior, menor teor de hidrogênio e nitrogênio. O aumento da temperatura final de carbonização reduziu o rendimento gravimétrico em carvão vegetal, o teor de materiais voláteis e de hidrogênio, havendo aumento do teor de carbono fixo, teor de carbono e poder calorífico superior. Os tratamentos com as melhores características energéticas foram os carvões de Ipê e Maçaranduba com extrativos produzidos a 600oC, além do carvão de Ipê e Maçaranduba com e sem extrativos obtidos a 700oC.