Avaliação da branqueabilidade de polpas kraft pré-o2 de eucalipto

Abstract

This aim of this study was to evaluate the bleachibility of pulp Kraft pre-O2 from five eucalyptus clones of Cenibra. The samples were subjected to delignification with chlorine dioxide followed by extraction reinforced with peroxide - Dht(EP). The performance of this process was evaluated by the gain in brightness, efficiency, selectivity and CTA (Chlorine Total Assets). It was found that the pulps evaluated have significant variability. The pulp A and B showed the best performance in bleaching Dht(EP). The clone pulp A showed a higher gain in brightness, bleachability, efficiency and cost of reagents, but lower selectivity and efficiency compared with B. However, their lower selectivity was offset by the higher initial viscosity and the final step Dht(EP) clone A showed highest viscosity for the same kappa number. The E and C clone pulp showed the lowest bleachability, but the clone C showed yield 5% higher than E. Therefore, the clone pulp E showed the worst bleaching performance by steps Dht(EP). The clone pulp D showed an intermediate performance when compared with other pulps.