Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/13995
metadata.revistascielo.dc.title: Extraction of wood hemicelluloses through NaOH leaching
metadata.revistascielo.dc.title.alternative: Remoção de hemiceluloses da madeira por tratamento de lixiviação alcalina com NaOH
metadata.revistascielo.dc.creator: Júnior, Dalton Longue
Colodette, Jorge Luiz
Gomes, Valéria Juste
metadata.revistascielo.dc.subject: Hemicellulose extraction
Alkaline leaching
Xylans
Lixiviação alcalina
Remoção de hemiceluloses
Xilanas
metadata.revistascielo.dc.publisher: CERNE
CERNE
metadata.revistascielo.dc.date: 13-May-2015
metadata.revistascielo.dc.identifier.citation: LONGUE JÚNIOR, D.; COLODETTE, J. L.; GOMES, V. J. Extraction of wood hemicelluloses through NaOH leaching. Cerne, Lavras, v. 16, n. 4, p. 423-429, out./dez. 2010.
metadata.revistascielo.dc.identifier: http://www.cerne.ufla.br/site/index.php/CERNE/article/view/112
metadata.revistascielo.dc.description: The aim of this work was to assess the impact of hemicellulose extraction in eucalyptus wood, through alkaline leaching (NaOH) of wood chips, on the subsequent kraft process (with varying sulphidity) and the quality of the pulp. The chips were initially saturated with water and treated with a NaOH solution in a liquor to wood ratio of 6:1 m3/t. The reaction times (3, 8, 14 and 16 hours), temperatures (70, 84 and 90°C) and NaOH concentrations (60, 80, 90, 120 and 156g/L) were assessed in atmospheric conditions. In the pressurized treatments (300 kPa), the reaction times, temperature and NaOH concentrations assessed were, respectively: 30, 60 and 120 minutes, 100°C and 100, 150 and 200g/L. The optimal alkaline leaching condition was determined taking into account the hemicellulose concentrations remaining in the chips and the gravimetrical yield. Chips not subjected to alkaline treatment (control) and leached with NaOH in optimum conditions were kraft cooked until kappa number 17 – 18. The results indicate that alkaline leaching of chips is not efficient in extracting hemicelluloses in the wood studied. The highest extraction of 4-Omethyl- glucuronoxylan acetate reached 42% in very severe conditions (100°C, 60 minutes, 200g/L of NaOH and 300 kPa pressure). The pulp yield of the leached chips was approximately 7% lower than that of the non-leached chips (control).
metadata.revistascielo.dc.language: por
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