Methods for the manufacture of cellulose nanocrystals
AssigneeDomtar Paper Company, LLC
InventorsBruno Marcoccia, Michael Edwards, Marvin Duncan Cooper
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Abstract
Embodiments of the present invention relates generally to methods and systems for the manufacture of cellulose nanocrystals. In one embodiment, a method for manufacturing cellulose nanocrystals comprises reacting lignocellulosic fibers with sulfuric acid in water, introducing a water-insoluble solvent to substantially terminate the reaction, separating a first stream comprising at least 70% of the unreacted sulfuric acid in the water-insoluble solvent from a second stream comprising a plurality of cellulose nanocrystals and the remainder of the unreacted sulfuric acid in water, and separating the cellulose nanocrystals from the second stream.
Claims25
A method for manufacturing cellulose nanocrystals comprising:
- reacting lignocellulosic fibers with sulfuric acid in water;
- introducing a water-insoluble solvent to substantially terminate the reaction;
- separating a first stream comprising at least 70% of the unreacted sulfuric acid in the water-insoluble solvent from a second stream comprising a plurality of cellulose nanocrystals and the remainder of the unreacted sulfuric acid in water;
- recovering the unreacted sulfuric acid in the second stream, wherein said recovering comprises introducing a second water-insoluble solvent to the second stream, separating a third stream comprising the unreacted sulfuric acid and the second water-insoluble solvent from a fourth stream comprising water, and separating the unreacted sulfuric acid from the second water-insoluble solvent;
- and
- separating the cellulose nanocrystals from the second stream.
A method for manufacturing cellulose nanocrystals comprising:
- reacting lignocellulosic fibers with sulfuric acid in water;
- introducing a water-insoluble solvent to the solution to substantially terminate the reaction;
- separating a first stream comprising at least 70% of the unreacted sulfuric acid in the water-insoluble solvent from a second stream comprising a plurality of cellulose nanocrystals and the remainder of the unreacted sulfuric acid in water;
- adjusting the pH of the second stream to greater than about 1;
- separating the cellulose nanocrystals from the second stream;
- and
- recovering substantially all of the unreacted sulfuric acid in the second stream, wherein said recovering comprises:
- introducing a second water-insoluble solvent to the second stream,
- separating a third stream comprising substantially all of the unreacted sulfuric acid and the second water-insoluble solvent from a fourth stream comprising water, and
- separating substantially all of the unreacted sulfuric acid from the second water-insoluble solvent.
Dependencies are inferred from the claim text.