OPTIMAL OZONE BLEACHING OF BAGASSE SODA-OXYGEN PULP

摘要

Ozone bleaching of bagasse soda-oxygen pulp was carried out in this study. Based on the results from the orthogonal experiment, it was found that influence of process variables on pulp properties was as follows: bleaching time > pulp consistency > ozone production. Additionally, a further single factor experiment confirmed that the optimal conditions of ozone bleaching were pulp consistency of 40%, ozone production of 0.9 kg·min.1/odt at ambient temperature for 10 min, and the resultant pulp showed kappa number of 9.21, brightness of 69.3%ISO, and viscosity of 682 mL·g.1, in which the degree of delignification, the increment of brightness, and the drop of viscosity of the bleached pulp were 43%, 10.7%ISO, and 145 mL·g.1, respectively. This pulp could, subsequently, be bleached to the brightness over 80%ISO with hydrogen peroxide bleaching under a mild condition, and its viscosity could be hardly lowered, and also the strength properties were comparable with unbleached pulp.