	US 12,188,181 B2
	Sulfite-based processes for producing nanocellulose, and compositions and products produced therefrom
Kimberly Nelson, Atlanta, GA (US); Theodora Retsina, Atlanta, GA (US); Vesa Pylkkanen, Atlanta, GA (US); and Ryan O′Connor, Minnetrista, MN (US)
Assigned to GranBio Intellectual Property Holdings, LLC, Thomaston, GA (US)
Filed by GranBio Intellectual Property Holdings, LLC, Minnetrista, MN (US)
Filed on Oct. 18, 2021, as Appl. No. 17/503,962.
Application 17/503,962 is a continuation of application No. 16/180,174, filed on Nov. 5, 2018, abandoned.
Application 16/180,174 is a continuation of application No. 15/180,356, filed on Jun. 13, 2016, abandoned.
Application 15/180,356 is a continuation of application No. 14/584,593, filed on Dec. 29, 2014, granted, now 9,399,840, issued on Jul. 26, 2016.
Claims priority of provisional application 61/921,535, filed on Dec. 30, 2013.
Prior Publication US 2022/0034038 A1, Feb. 3, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. D21H 11/18 (2006.01); C13K 1/02 (2006.01); D21C 3/04 (2006.01); D21C 3/06 (2006.01); D21C 9/00 (2006.01); D21C 9/10 (2006.01); D21H 11/06 (2006.01); D21H 17/66 (2006.01); D21H 21/32 (2006.01)

CPC D21H 11/18 (2013.01) [C13K 1/02 (2013.01); D21C 3/04 (2013.01); D21C 3/06 (2013.01); D21C 9/007 (2013.01); D21C 9/10 (2013.01); D21H 11/06 (2013.01); D21H 17/66 (2013.01); D21H 21/32 (2013.01)]

14 Claims

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 a solution consisting of sulfur dioxide or a compound derived therefrom and water, wherein said solution does not contain a solvent for lignin, wherein said compound is selected from the group consisting of sulfurous acid, sulfite ions, sulfite salts, lignosulfonic acid, and combinations thereof, and wherein said fractionating is conducted at a pH selected from about 0 to about 6, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin;

(c) mechanically treating said cellulose-rich solids to form cellulose nanofibrils and/or cellulose nanocrystals, thereby generating a nanocellulose material having a crystallinity of at least 70%; and

(d) recovering said nanocellulose material,

wherein no enzyme treatment is employed during said process,

wherein no acid hydrolysis of said cellulose-rich solids is employed during said process following step (b), and

wherein said nanocellulose material is at least partially hydrophobic via deposition of at least some of said lignin onto a surface of said cellulose-rich solids during step (b) and/or via deposition of at least some of said lignin onto a surface of said nanocellulose material during step (c) or step (d).