Pulping of Sugarcane Bagasse and Straw and Biobleaching of the Pulps: Conditions Parameters and Recycling of Enzymes

Alternative pulping and bleaching systems have been studied by several research groups around the world. Different lignocellulosics were evaluated as raw material for this aim. In our group we combined organosolv pulping (acetosolv and ethanol/water) of sugarcane bagasse and straw with enzymatic bleaching with xylanases. Viscosity of the pulps ranged from 9-19 cP and kappa number was lesser than 30. Xylanase from different sources was applied in the pulp, varying dosage and time. Pulps presented lower kappa number even after 4 h of treatment. The reusing of the xylanase was evaluated and the activity and viscosity of pulps were maintained after 2 or 3 reuses. Viscosity was used as a control parameter since obtained pulps should be used as cellulose derivatives. Pulps were also analyzed for brightness and holocellulose and α-cellulose contents.