Assessment of Q(OP)D(PO) bleachability of softwood kraft pulp

Abstract Bleachability is evaluated as how easily a pulp sample bleached and it depends on the structure of residual lignin carbohydrates. Also, bleachability varies depending bleaching sequence. ECF light sequences have been improved significantly in recent years. However, we still don’t fully understand bleach plants are optimally run. This work studies softwood kraft an sequence, (OO)Q(OP)D(PO). Three samples with brown stock kappa number 27, 32 35 were studied for lignin, hexenuronic acid carbohydrate content. It was found that stages highly delignifying, beneficial higher delignifying bleachability. where objective brightness increase, gain by lower number. We also intended to determine which three had best suited this particular According our results, most effective around 32. Although even resulted yield after cooking, seemed sequence cannot preserve gain.