Continuous Chemical Supplement, a Novel Solution to Improve the Efficiency of Peroxide Bleaching

Abstract

Abstract:In conventional peroxide bleaching of chemi-thermomechanical pulp (CTMP), the bleaching efficiency of hydrogen peroxide (H2O2) is far lower than its expected level. In this paper, a novel bleaching method is proposed to improve the H2O2 bleaching efficiency of poplar CTMP.This novel method, namely Continuous Chemical Supplement (CCS), maintained constant concentrations of H2O2 and total alkali in the bleaching system for a long time by supplementing continuously H2O2 and NaOH solutions using peristaltic pumps. The H2O2 decomposition was reduced and the brightness was improved. Consequently, the bleaching efficiency was improved.The experimental results indicated that the bleaching efficiency reached 16.5 by CCS, which was significantly higher than that obtained by the traditional high-consistency bleaching method (7.4).This novel bleaching method may be helpful to industrial production practice.