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Utilize este identificador para citar ou criar um link para este item: http://acervodigital.unesp.br/handle/11449/9041
Título: 
Evaluation of the kinetics of xylose formation from dilute sulfuric acid hydrolysis of forest residues of Eucalyptus grandis
Autor(es): 
Instituição: 
  • Universidade Estadual Paulista (UNESP)
  • Instituto Nacional de Pesquisas Espaciais (INPE)
  • Universidade de São Paulo (USP)
ISSN: 
0888-5885
Resumo: 
Dilute acid hydrolysis studies were performed on forest residues of Eucalyptus grandis, in a cylindrical reactor of stainless steel. The kinetics of this hydrolysis reaction was investigated employing 0.65% sulfuric acid, a residue/acid solution ratio of 1/9 (w/w), temperatures of 130, 140, 150, and 160 degrees C, and reaction times in the range 20-100 min. The results showed that, under the optimized conditions of acid hydrolysis employed in this study, the variables temperature and reaction time had a strong influence on hemicellulose removal and a small influence on the degree of lignin and cellulose removal. The highest xylose extraction yield was 87.6% attained at 160 degrees C, after 70 min reaction time, simultaneously with the formation of decomposition products, namely 2.8% acetic acid, 0.6% furfural, and 0.06% 5-hydroxymethylfurfural. A similar xylose extraction yield (82.8%) was observed at 150 degrees C after 100 min, with the formation of 3.2% acetic acid, 1.0% furfural, and 0.07% 5-hydroxymethylfurfural. The kinetic parameters determined at 130, 140, 150, and 160 degrees C for degradation of xylan present in the hemicellulose of the eucalyptus forest residue during the formation of xylose were the first-order reaction rate constants (k) for each temperature, 1.22 x 10(-4), 2.12 x 10(-4), 5.43 x 10(-4), and 9.05 x 10(-4) s(-1), respectively, and an activation energy (E-a) of 101.3 kJ mol(-1).
Data de publicação: 
28-Mar-2007
Citação: 
Industrial & Engineering Chemistry Research. Washington: Amer Chemical Soc, v. 46, n. 7, p. 1938-1944, 2007.
Duração: 
1938-1944
Publicador: 
Amer Chemical Soc
Fonte: 
http://dx.doi.org/10.1021/ie0607494
Endereço permanente: 
Direitos de acesso: 
Acesso restrito
Tipo: 
outro
Fonte completa:
http://repositorio.unesp.br/handle/11449/9041
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