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Kinetics of acid-catalysed delignification of Eucalyptus globulus wood by acetic acid

Wood science and technology 29(4): 267-275

Kinetics of acid-catalysed delignification of Eucalyptus globulus wood by acetic acid

The kinetics of HCl-catalysed delignification of Eucalyptus globulus wood by 70% (w/w) acetic acid solution were satisfactorily explained by a model in which 5% of the lignin fraction could not be eliminated and the remaining 95% was eliminated by a single process which, in view of the activation energy calculated from the data was attributed to the hydrolysis of alpha-aryl ether bonds. The selectivity of the process was effectively independent of HCl concentration and operating temperature for pulp yields > 50%. At high temperature (160 degrees C) and catalyst concentration (0.027 M HCl), lignin condensation and precipitation became significant and the data were better fitted by a model comprising two consecutive processes: lignin solubilization followed by lignin condensation.

Accession: 002646256

DOI: 10.1007/bf00202086

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