Removal of caustic in hemicellulose caustic
CA 2236233 C · Owner: Gallivan, Timothy J. · Inventors: Gallivan, Timothy J.; Jackson, John R.; Moran, Stephen W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pulping chemicals and hemicellulose are recovered from a starting solution essentially free of lignin but containing a mixture of hemicellulose and caustic by electrolysing this solution in the anolyte compartment of an electrolytic cell. By electrolysis, the concentration of caustic in the anolyte is decreased and the concentration of caustic in a catholyte of said cell is increased so as to allow recovery of about 60 to about 80 percent of the caustic contained in the hemicellulose caustic starting solution.
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 October 30, 1996 and granted April 16, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 30, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 30, 2018.
- 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.