Process for lignin recovery
CA 1267648 C · Owner: Katzen, Raphael · Inventors: Cronlund, Malcolm; Lora, Jairo H.; Wu, Chih F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Lignin is precipitated in high yields and at high rates from a black liquor produced by pulping wood at high temperatures and pressures with an aqueous lower aliphatic alcohol solvent. The lignin is precipitated by diluting the black liquor with water and an acid to form a solution with a pH of less than about 3 an, alcohol content of less than about 30% by volume and a temperature of less than about 60°C. The precipitated lignin when, subsequently dried, is in the form of a powder which requires little or no crushing to convert it into a fine uniform size suitable for use without further significant processing.
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
- Granted April 10, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 10, 2007.
- 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.