Chlorine Dioxide Delignification Kinetics and Eop Extraction of Softwood Kraft Pulp

Abstract

A kinetic model for 100% chlorine dioxide delignification based on experimental data is presented. From the unbleached kappa number, chlorine dioxide charge and reaction time, the model predicts kappa, brightness and residuals after the first bleaching stage. The model consists of two ordinary differential equations representing the slow and fast reactions of lignin with chlorine dioxide. In addition we found that the relationship between the chlorine dioxide consumption and the kappa number decrease was linear in the range studied and independent of the unbleached pulp kappa number.