Fractionating - A way to save bleaching chemicals?

In the future, it will probably be more common to customize pulp to give certain desired paper properties and therefore it is interesting to study the bleachability and the bleaching chemical consumption of various pulp fractions.. There is a potential both for quality improvement and cost reduction by the bleaching of fractions. The results here indicate that it is possible to save bleaching chemicals by fractionating the pulp before bleaching. Using 40 kg/t H2O2, it is possible to decrease the light-absorption coefficient for the whole pulp by similar to 23% more if the fractions are separately bleached optimally compared to bleaching the whole pulp alone optimally. The bleaching chemical consumption can be lowered by at least 9.6% for the same reduction in absorption coefficient if the fractions are separately bleached, compared to bleaching the whole pulp alone optimally.