Bleaching stage using xylanase with hydrogen peroxide, peracids, or a combination thereof
CA 2436765 A1 · Owner: Tolan, Jeffrey · Inventors: Suchy, Miro; Tolan, Jeffrey
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
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 the , pulp. The method allows the mill to use both xylanase and peracids in a single bleaching tower to decrease the usage of chlorine dioxide and other bleaching chemicals. The pulp bleaching method of the present invention may be performed in a pulp mill as part of a complex pulp bleaching process.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 3, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 3, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 2024.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.