Nanocellulose production co-located at a pulp and paper mill
Some variations provide a process for producing a nanocellulose material, comprising: providing a biomass feedstock comprising a bleached or unbleached pulp material; fractionating the feedstock in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form cellulose fibrils and/or cellulose crystals, thereby generating a nanocellulose material. The process is preferably co-located with, or adjacent to, a mill that generates the pulp material. There are several advantages of a bolt-on AVAP® nanocellulose plant to an existing pulp mill, as disclosed herein.
1. A process for producing a nanocellulose material, said process comprising:
(a) providing an unbleached pulp material, wherein said unbleached pulp material is a chemical pulp, a chemimechanical pulp, a chemithermomechanical pulp, or a combination thereof, wherein said unbleached pulp material is obtained from a distinct process, and wherein said unbleached pulp material received in this step (a) has already gone through complete chemical pulping, chemimechanical pulping, and/or chemithermomechanical pulping;
(b) in a digestor, fractionating said unbleached pulp material in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein said unbleached pulp material is fed to said digestor at a solids concentration of from 30 wt % solids to 50 wt % solids;
(c) mechanically treating said cellulose-rich solids to form cellulose fibrils and/or cellulose crystals, thereby generating a nanocellulose material having a crystallinity of at least 60%; and
(d) recovering said nanocellulose material,
wherein said process is co-located with a pulping process that generates said unbleached pulp material.
2. The process of claim 1 , wherein said unbleached pulp material is a chemical pulp consisting of a kraft pulp, a sulfite pulp, a soda pulp, or a combination thereof.
3. The process of claim 1 , wherein said unbleached pulp material is recycled pulp from a pulp and paper mill.
4. The process of claim 1 , wherein said unbleached pulp material is recycled pulp from a paper product.
5. The process of claim 1 , wherein said acid is a sulfur-containing acid.
6. The process of claim 5 , wherein said sulfur-containing acid is selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, sulfonic acids, lignosulfonic acids, and combinations thereof.
7. The process of claim 1 , wherein said solvent for lignin is an aliphatic alcohol.
8. The process of claim 7 , wherein said aliphatic alcohol is ethanol.
9. The process of claim 1 , wherein said unbleached pulp material is obtained from a press line of a pulp machine that is part of said distinct process, and wherein said process further comprises shredding or grinding a pulp sheet into said unbleached pulp material.
10. The process of claim 1 , wherein said unbleached pulp material is never dried between said distinct process and said process.
11. A process for producing a nanocellulose material, said process comprising:
(a) providing a bleached pulp material, wherein said bleached pulp material is a chemical pulp, a chemimechanical pulp, a chemithermomechanical pulp, or a combination thereof, wherein said bleached pulp material is obtained from a distinct process, and wherein said bleached pulp material received in this step (a) has already gone through complete chemical pulping with bleaching, chemimechanical pulping with bleaching, and/or chemithermomechanical pulping with bleaching;
(b) in a digestor, fractionating said bleached pulp material in the presence of an acid and water, and optionally a solvent, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein said bleached pulp material is fed to said digestor at a solids concentration of from 30 wt % solids to 50 wt % solids;
(c) mechanically treating said cellulose-rich solids to form cellulose fibrils and/or cellulose crystals, thereby generating a nanocellulose material having a crystallinity of at least 60%; and
(d) recovering said nanocellulose material,
wherein said process is co-located with a pulping process that generates said bleached pulp material.
12. The process of claim 11 , wherein said bleached pulp material is a chemical pulp consisting of a kraft pulp, a sulfite pulp, a soda pulp, or a combination thereof.
13. The process of claim 11 , wherein said bleached pulp material is recycled pulp from a pulp and paper mill.
14. The process of claim 11 , wherein said bleached pulp material is recycled pulp from a paper product.
15. The process of claim 11 , wherein said acid is a sulfur-containing acid.
16. The process of claim 15 , wherein said sulfur-containing acid is selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, sulfonic acids, lignosulfonic acids, and combinations thereof.
17. The process of claim 11 , wherein said solvent is present and is an aliphatic alcohol.
18. The process of claim 17 , wherein said aliphatic alcohol is ethanol.
19. The process of claim 11 , wherein said bleached pulp material is obtained from a press line of a pulp machine that is part of said distinct process, and wherein said process further comprises shredding or grinding a pulp sheet into said bleached pulp material.
20. The process of claim 11 , wherein said bleached pulp material is never dried between said distinct process and said process.