New highly efficient method of polyoxometalate (POM) catalyzed ozone bleaching of industrial eucalypt (E. globulus) kraft pulp

Abstract

The highly efficient and selective environmentally benign bleaching approach using polyoxometalate (POMs) catalyzed ozonation of chemical pulps in organic solvent reaction media has been developed. The Keggin-type molybdovanadophosphate heteropolyanions (HPAs) showed a well-defined capacity for ozonation improvement in the presence of number polar low-boiling aprotic and protic organic solvents. Under optimized conditions, the solvent-based HPA-catalyzed ozone bleaching of industrial eucalypt kraft pulp showed remarkable brightness improvement by 15.1% ISO, with additional lignin removal by 39.4% and increase in intrinsic viscosity by 3% in comparison with conventional ozone bleaching technique.