Pulping of lignocellulosic materials and recovery of resultant by-products
CA 2101754 A1 · Owner: Alcell Technologies Inc. · Inventors: Winner, Stephen R.; Leblanc, Ron; Cronlund, Malcolm
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Filtrates from the bleaching and delignification of the pulp are recycled for reuse in pulping, separation and recovery of lignin, (66) and other by-products which results in significant energy savings and mitigation if not the elimination of pollution typically associated with bleaching. This invention also relates to products derived from the process and apparatus for carrying out the process. Lignins of various molecular weights and by-products of the pulping process are also recovered (66). The lignins are precipitated in high yields and at a high rate from a black liquor (40) produced by pulping wood at high temperature and pressures with an aqueous lower aliphatic alcohol solvent. …
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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 January 29, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 29, 2014.
- 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
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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.