Processes and apparatus for producing nanocellulose, and compositions and products produced therefrom

摘要

Processes disclosed are capable of converting biomass into high-crystallinity nanocellulose with surprisingly low mechanical energy input. In some variations, the process includes fractionating biomass with an acid (such as sulfur dioxide), a solvent (such as ethanol), and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form nanofibrils and/or nanocrystals. The total mechanical energy may be less than 500 kilowatt-hours per ton. The crystallinity of the nanocellulose material may be 80% or higher, translating into good reinforcing properties for composites. The nanocellulose material may include nanofibrillated cellulose, nanocrystalline cellulose, or both. In some embodiments, the nanocellulose material is hydrophobic via deposition of some lignin onto the cellulose surface. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers. These polymers may be combined with the nanocellulose to form completely renewable composites.

主权项

1. A process for producing a nanocellulose material, said process comprising:
(a) providing a lignocellulosic biomass feedstock; (b) fractionating said 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; (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 during step (c), said cellulose-rich solids are treated with a total mechanical energy of less than 1000 kilowatt-hours per ton of said cellulose-rich solids.