Application of a catalyst in peroxide bleaching of eucalyptus kraft pulp

A binuclear [Mn(III)Mn(IV)(mu-O)(2)(mu-CH3COO)L](ClO4(-))(2) complex with L =1,2 Bis-(4,7-dimethyl-1.4,7-triazacyclonon-1-yl)-ethane, described as a se lective catalyst in hydrogen peroxide bleaching of softwood pulps, was test ed in hardwood kraft pulp bleaching. The catalyst application gave rise to a higher consumption of peroxide which resulted in higher pulp brightness. The delignification improvement caused by the catalyst was shown to be much lower compared to catalysed peroxide bleaching of softwood kraft pulp. In contrast to the results of softwood pulp bleaching no selectivity improveme nts could be found when using the catalyst in bleaching of eucalyptus kraft pulp.