Kinetic Models for Peroxide Bleaching Under Alkaline Conditions. I. One and Two Chromophore Models

Abstract

Several kinetic models for alkaline peroxide bleaching of Eucalypt mechanical pulp have been examined. A previously reported kinetic model, developed to describe peroxide bleaching of softwoods, was found to be inadequate. The models proposed here assume two distinct categories of chromophores which are eliminated through first order processes, rather than the high orders for reaction processes suggested in previous kinetic analyses. Our model enables prediction of a maximum in the rate of bleaching in the range pH 11–12, whereas previous models imply that the rate of chromophore elimination increases continuously with hydroxide ion concentration.