Relação entre as propriedades da madeira e as características dos produtos finais para energia e celulose
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Data
2019-01-30
Autores
Pupo, Camyla Heckler
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Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho teve por objetivo avaliar a relação que há entre as propriedades da madeira e as características dos produtos finais para celulose e energia. O material consistiu de árvores de Eucalyptus grandis (7 anos) e Eucalyptus saligna (nas idades de 5,5; 6; 7 e 17 anos). Foram realizadas as seguintes análises: parâmetros dendrométricos, densidade básica e composição química da madeira, carbono fixo e teor de voláteis, poder calorífico, Analise Termogravimétrica (TGA) e polpação kratf. Os resultados mostraram que as características que diferem o E. saligna nas idades de 5,5 e 6 anos (tipo de plantio e procedência), tiveram influência na propriedade física da madeira, no processo de polpação e no Poder Calorífico Superior (PCS) das árvores. O material genético que apresentou maior potencial para produção de celulose, foi o E. saligna (5,5 anos), com alto rendimento depurado e baixos rejeitos. Para uso energético, os dois materiais apresentaram resultados satisfatórios. Porém, o material genético com maior potencial foi o E. saligna (6 anos). A espécie apresentou maior densidade básica, maiores teores de extrativos e lignina e menor teor de umidade, com maior PCS em Kcal/m3 e maior % Carbono fixo. Na comparação entre E. saligna e E. grandis, observou-se que embora essas duas espécies tenham sido plantadas sobre as mesmas condições (solo, adubação, clima), fica evidente a influência da espécie, dada as diferenças em suas propriedades da madeira e em seus potenciais para uso energético e de celulose. Na polpação a espécie E. grandis apresentou resultados mais satisfatórios, com menos rejeitos e maior rendimento depurado. Para uso energético a espécie que mais se destaca pelas propriedades químicas da madeira e elevados valores de PCS, carbono fixo e densidade básica é o E. saligna (7 anos). Na terceira condição analisada, a idade foi um fator influenciador, afetando as propriedades químicas e físicas da madeira. Onde, o E. saligna de 17 anos se difere estatisticamente em quase todos os parâmetros de qualidade. Na análise de Correlação de Pearson, as correlações entre as propriedades da madeira e a polpação Kraft foram muito baixas, a variável que melhor se correlacionou foi a densidade básica, com correlação negativa para o consumo específico de madeira. Nas propriedades energéticas, as únicas propriedades da madeira que apresentaram influência significativa foram a densidade básica e o teor de cinzas, que se correlacionaram com o carbono fixo e a taxa de degradação, respectivamente. Posto isto, pode-se concluir que as propriedades da madeira podem afetar diretamente nos resultados da polpação e nas características energéticas do material. Nas condições analisadas, fica evidenciada a influência da espécie, tipo de plantio, procedência e idade, com maior ou menor influência. Para polpação kraft se restringe o uso de algumas procedências, mas para uso energético, os cinco materiais avaliados podem ser utilizados. Sendo assim, é indispensável uma análise criteriosa das propriedades da madeira na escolha de um material genético lenhoso, onde se deve primeiramente estabelecer o uso final que se destinará a madeira.
The objective of this work was to evaluate the relationship between the properties of wood and the characteristics of the final products for cellulose and energy. The material consisted of Eucalyptus grandis (7 years) and Eucalyptus saligna trees (ages 5.5, 6, 7 and 17 years). The following analyzes were performed: dendrometric parameters, basic density and chemical composition of wood, fixed carbon and volatile content, Calorific Value (CV), Thermogravimetric Analysis (TGA) and Kratf Pulping. The results showed that the characteristics that differ from E. saligna at the ages of 5.5 and 6 years (type of planting and provenance) had an influence on the physical property of the wood, the pulping process and the Calorific Value. The genetic material that presented the greatest potential for cellulose production was E. saligna (5.5 years), with high yield and low rejects. For energy use, both materials presented satisfactory results. However, the genetic material with the greatest potential was E. saligna (6 years). The species presented higher basic density, higher extractive and lignin contents and lower moisture content, with higher CV in Kcal/m3 and higher % Fixed Carbon. In the comparison between E. saligna and E. grandis, it was observed that although these two species were planted under the same conditions (soil, fertilization, climate), the influence of the species is evident given, the differences in their properties of wood and in their potential for energy and cellulose use. In the pulping the E. grandis species presented more satisfactory results, with fewer rejects and higher yield. For energy use the specie that stand out most for the chemical properties of wood and high values of CV, fixed carbon and basic density is E. saligna (7 years old). In the third analyzed condition, age was an influencing factor, affecting the chemical and physical properties of the wood. Where 17-year-old E. saligna differs statistically from almost all quality parameters. In the Pearson correlation analysis, the correlations between wood properties and Kraft pulping were very low, the variable that correlated best was the basic density, with negative correlation for the specific wood consumption. In the energetic properties, the only wood properties that had a significant influence were the basic density and the ash content, which correlated with the fixed carbon and the rate of degradation, respectively. Thus, it can be concluded that the properties of wood can directly affect the pulping results and the energetic characteristics of the material. In the conditions analyzed, the influence of the species, type of planting, provenance and age, with greater or less influence, is evidenced. Kraft pulping restricts the use of some species, but for energy use, the five evaluated materials can be used. Therefore, a careful analysis of the properties of wood in the choice of a woody genetic material is indispensable, in which the final use for wood must first be established.
The objective of this work was to evaluate the relationship between the properties of wood and the characteristics of the final products for cellulose and energy. The material consisted of Eucalyptus grandis (7 years) and Eucalyptus saligna trees (ages 5.5, 6, 7 and 17 years). The following analyzes were performed: dendrometric parameters, basic density and chemical composition of wood, fixed carbon and volatile content, Calorific Value (CV), Thermogravimetric Analysis (TGA) and Kratf Pulping. The results showed that the characteristics that differ from E. saligna at the ages of 5.5 and 6 years (type of planting and provenance) had an influence on the physical property of the wood, the pulping process and the Calorific Value. The genetic material that presented the greatest potential for cellulose production was E. saligna (5.5 years), with high yield and low rejects. For energy use, both materials presented satisfactory results. However, the genetic material with the greatest potential was E. saligna (6 years). The species presented higher basic density, higher extractive and lignin contents and lower moisture content, with higher CV in Kcal/m3 and higher % Fixed Carbon. In the comparison between E. saligna and E. grandis, it was observed that although these two species were planted under the same conditions (soil, fertilization, climate), the influence of the species is evident given, the differences in their properties of wood and in their potential for energy and cellulose use. In the pulping the E. grandis species presented more satisfactory results, with fewer rejects and higher yield. For energy use the specie that stand out most for the chemical properties of wood and high values of CV, fixed carbon and basic density is E. saligna (7 years old). In the third analyzed condition, age was an influencing factor, affecting the chemical and physical properties of the wood. Where 17-year-old E. saligna differs statistically from almost all quality parameters. In the Pearson correlation analysis, the correlations between wood properties and Kraft pulping were very low, the variable that correlated best was the basic density, with negative correlation for the specific wood consumption. In the energetic properties, the only wood properties that had a significant influence were the basic density and the ash content, which correlated with the fixed carbon and the rate of degradation, respectively. Thus, it can be concluded that the properties of wood can directly affect the pulping results and the energetic characteristics of the material. In the conditions analyzed, the influence of the species, type of planting, provenance and age, with greater or less influence, is evidenced. Kraft pulping restricts the use of some species, but for energy use, the five evaluated materials can be used. Therefore, a careful analysis of the properties of wood in the choice of a woody genetic material is indispensable, in which the final use for wood must first be established.
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Palavras-chave
Poder calorífico, Análise termogravimétrica, Polpação kraft, Eucalyptus saligna, Eucalyptus grandis, Calorific value, Thermogravimetric analysis, kraft pulping