Effect of Lignin Content on Ozone Bleaching at Medium Consistency Condition, 1992 Pulping Conference Proceedings

An experimental investigation is conducted to study the effect of lignin content on ozone bleaching at medium consistency condition. Only chemical pulps is used to bleach by ozone/ozygen. The kappa numbers of unbleached chemical pulps are somewhat between 10 to 50. The medium consistency condition is chosen because the medium consistency treatment is more adaptable in current mill practice. The kappa number and viscosity are used to indicate the effect of lignin content on ozone bleaching. Bleaching results at a constant ozone application level and varying the lignin content of pulps are summarized. The data are useful to develop the ozone bleaching modular for computerized ozone bleaching simulation and optimization of ozone bleaching. The data are also useful for examining the possibility of ozone bleaching at medium consistency condition. The results show that certain correlations exist between lignin content of pulps and the efficiency of ozone bleaching.