Biobleaching of Bagasse Pulp with Xylanase Enzymes and Hydrogen Peroxide

The effect of the operating conditions (temperature, time, pH, enzyme level and pulp consistency) used in the enzymatic step of a XP (Cartazyme-hydrogen peroxide) sequence for bleaching Kraft pulp from bagasse on various properties of the resulting pulp and paper sheet products was studied. The quality of bagasse used, was examined by its yield, brightness,viscosity and the Kappa number. Finally, the quality of paper sheets produced were examined by their brightness, breaking length, burst index and tear index. The total number of experiments required for five independent variables was calculated from N=2k+2k+1 equation, in which k is the number of independent variables. The results of 43 experiments performed, were processed using the MINITAB software suite which provided equations that reproduced the values of the dependent variables with less error. The application of the steepest ascent method has been carefully inserted in the experimental design section the identification of the most suitable conditions for optimizing the values of the dependent variables. Based on the results, using enzyme level 6 (IU/g) , temperature 35°C, pH 5 and pulp consistency 12% for 2 hrs. in the enzymatic step provided paper sheets of acceptable quality.