Ozone augmentation of an enzyme-based kraft pulp-bleaching process

摘要

an improved non-chlorine pulp-bleaching process has been developed comp;rised of xylanase enzyme treatment in compination with oxygen, ozone and alkaline hydrogen peroside bleaching stages. Xylanase treatment of kraft pups improves bleachability in subsequent stages. Eucalyptus hardwood pulp, delignified with a sequence of oxygen, xylanase and ozone stages (i.g., O-X-Z) was found to have consistently lower kappa number and higher bridhtness at the same level of ozone charge compared to an O-Z bleached pulp without the enzyme stage.