Comportamento dos componentes químicos da madeira de eucalipto na polpação Lo-Solids®

• Ano de defesa: 2006
• Autor(a) principal: Pimenta, Leonardo Rodrigo
• Orientador(a): Gomide, José Lívio
• Banca de defesa: Colodette, Jorge Luiz , Oliveira, Rubens Chaves de , Ventorim, Gustavo , Silva, Marcelo Rodrigues da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência Florestal
• Departamento: Manejo Florestal; Meio Ambiente e Conservação da Natureza; Silvicultura; Tecnologia e Utilização de
• País: BR
• Palavras-chave em Português: Polpação kraft; Madeira; Química; Eucalipto
• Palavras-chave em Inglês: Kraft pulping; Wood; Chemistry; Eucalyptus
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::TECNOLOGIA E UTILIZACAO DE PRODUTOS FLORESTAIS
• Link de acesso: http://locus.ufv.br/handle/123456789/3095

The objective of this work went evaluate the representatives chemists of the eucalyptus wood behavior in the different phases of the process of pulpation kraft Lo-Solids®, simulating in laboratory the different areas of the digestor. The used wood was collected in the form of shavingses in Votorantim Celulose and Paper, that it also gave the industrial white lique ur used in the study. Cooking was accomplished in copy with objective of obtaining number kappa 16 ± 0.5 and collected samples of shavings semidelignificated, pulp and black liqueur in five points of the process: final of the impregnation zone (45 min); half of the zone of superior cooking (90 min); final of the zone of superior cooking (120 min); half of the zone of inferior cooking (180 min) and in the end of the cooking (240 min). The results demonstrated that there was an intense degradation of the carbohidrates (21.7%), lignine (65.8%), extractive lipofilics (87.2%) and total degradation of the groups acetil when the cooking reached the first half of the zone of superior cooking, causing an intense alkali consumption (69.1%). The delignification in the cooking Lo-Solids® happened in four phases, being the phase of "Main" Delignification divided in two phases. During the impregnation there was intense reduction in the hemicelluloses text (25.4%) and, in smaller intensity, of cellulose (3.9%). The largest reduction in the cellulose text (6.3%) it happened when the half of the zone of superior cooking was reached, when 23.5% of the hemicelluloses were removed. In the final stage of cooking the cellulose was not very degraded (0.5%) and the hemicelluloses didn't present reduction in its text, fact explained by the xilanes precipitation in elapsing of this stage, compensating the degradation of the other hemicelluloses. At the end of the cooking a total reduction of 14.2% was observed in the cellulose text and the hemicelluloses they presented a removal of 53.9% of its representatives. The process Lo-Solids® went more selective in to second half of the zone of superior cooking, result reduced degradation of the carbohidrates and intense delignification. In the phase of impregnation of the cooking lignines was removed with larger proportion of units guaiacila, already in the phase of main delignification the removed lignine was progressively richer in units siringila. In the impregnation zone there was a fast formation of the acid hexenuronic and in the first half of the zone of superior cooking the text of acid hexenuronic decreased, mainly due to its hidrolise of the xilanes chains, starting from its point text it increased until the end of the cooking. The text of manganese decreased during the whole cooking, to the opposite the text of iron that increased, demonstrating to the resistance of this element the alkaline lixiviation. The analyses of the black liqueur demonstrated that so much the text of solids, as the alkaline concentration, they stayed relatively homogeneous along the process. In the final stage of the process (60 final minutes), in spite of the low revenue loss (1%) and a considerable reduction of the number kappa (5.5 units), it happened great fall in the viscosity of the pulp (31.8 cP), probably caused by an increase in the breaking of the connections (1-4) of the cellulose chains.