BLEACHING STAGE USING XYLANASE WITH HYDROGEN PEROXIDE, PERACIDS, OR A COMBINATION THEREOF

摘要

The present invention discloses methods of bleaching chemical pulp that combine xylanase enzymes with hydrogen peroxide, peracids, or a mixture. The method comprises the steps of carrying out a chemical pulping operation, optionally followed by delignifying the pulp with oxygen, then combining xylanase enzymes with hydrogen peroxide, peracids, or a mixture to bleach th e pulp. The method allows the mill to use both xylanase and peracids in a sing le bleaching tower to decrease the usage of chlorine dioxide and other bleachin g chemicals. The pulp bleaching method of the present invention may be perform ed in a pulp mill as part of a complex pulp bleaching process.