Extracting value from Eucalyptus wood before kraft pulping: Effects of hemicelluloses solubilization on pulp properties

Eucalyptus globulus wood samples were subjected to autohydrolysis for extracting hemicelluloses, and the resulting solids were assayed as substrates for kraft pulping and further Totally Chlorine Free (TCF) bleaching. The susceptibility of treated solids to kraft processing was assessed under selected experiments covering the optimum experimental range. In order to establish a basis for comparison, samples of untreated wood were also subjected to kraft delignification. The best kraft pulps obtained from autohydrolyzed solids were subjected to an optimized TCF bleaching sequence involving double alkaline oxygen and pressurized H2O2 processing, and characterized using standard methods. The suitability of the final product obtained by autohydrolysis-kraft delignification-TCF bleaching for specific purposes is discussed on the basis of the experimental results.