Processes and systems for producing nanocellulose from old corrugated containers

Patent metadata

Field	Value
Publication number	US-12018432-B2
Application number	US-202016996414-A
Country	US
Kind code	B2
Filing date	Aug 18, 2020
Priority date	Jun 28, 2016
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

In some variations, OCC is screened, cleaned, deinked, and mechanically refined to generate cellulose nanofibrils. The OCC may be subjected to further chemical, physical, or thermal processing, prior to mechanical refining. For example, the OCC may be subjected to hot-water extraction, or fractionation with an acid catalyst, a solvent for lignin, and water. In certain embodiments to produce cellulose nanocrystals, OCC is exposed to AVAP® digestor conditions. The resulting pulp is optionally bleached and is mechanically refined to generate cellulose nanocrystals. In certain embodiments to produce cellulose nanofibrils, OCC is exposed to GreenBox+® digestor conditions. The resulting pulp is mechanically refined to generate cellulose nanofibrils. The site of a system to convert OCC to nanocellulose may be co-located with an existing OCC processing site. The nanocellulose line may be a bolt-on retrofit system to existing infrastructure. In other embodiments, a dedicated plant for converting OCC to nanocellulose is used.

First claim

What is claimed is:

1. A process for producing cellulose nanofibrils and/or cellulose nanocrystals from old corrugated containers and incorporating said cellulose nanofibrils and/or cellulose nanocrystals into corrugating medium pulp, said process comprising:
(a) providing a feedstock comprising old corrugated containers;
(b) screening and cleaning said feedstock to remove one or more non-cellulosic components contained in said feedstock, to generate a cleaned feedstock;
(c) thermally treating said cleaned feedstock with a solution consisting essentially of steam or hot water, to generate a treated feedstock;
(d) mechanically refining said treated feedstock to generate cellulose nanofibrils and/or cellulose nanocrystals; and
(e) introducing said cellulose nanofibrils and/or cellulose nanocrystals to a material comprising corrugating medium pulp,
wherein said treated feedstock is bleached prior to step (d), or wherein said cellulose nanofibrils and/or cellulose nanocrystals are bleached following step (d).

2. The process of claim 1 , wherein said one or more non-cellulosic components removed in step (b) include components selected from the groups consisting of solvents, resins, lubricants, solubilizers, surfactants, particulate matter, pigments, dyes, fluorescents, and combinations thereof.

3. The process of claim 1 , wherein said cellulase enzymes are introduced during step (b).

4. The process of claim 1 , wherein said cellulase enzymes are introduced during step (d).

5. A process for producing cellulose nanofibrils and/or cellulose nanocrystals from old corrugated containers and incorporating said cellulose nanofibrils and/or cellulose nanocrystals into corrugating medium pulp, said process comprising:
(a) providing a feedstock comprising old corrugated containers;
(b) screening and cleaning said feedstock to remove one or more non-cellulosic components contained in said feedstock, to generate a cleaned feedstock;
(c) thermally treating said cleaned feedstock with a solution consisting essentially of steam or hot water, to generate a treated feedstock;
(d) mechanically refining said treated feedstock to generate cellulose nanofibrils and/or cellulose nanocrystals; and
(e) introducing said cellulose nanofibrils and/or cellulose nanocrystals to a material comprising corrugating medium pulp,
wherein said cellulase enzymes are introduced during step (b), between steps (c) and (d), or during step (d).

6. The process of claim 5 , wherein said cellulase enzymes are introduced during step (b).

7. The process of claim 5 , wherein said cellulase enzymes are introduced between steps (c) and (d).

8. The process of claim 5 , wherein said cellulase enzymes are introduced during step (d).

Assignees

• Granbio Intellectual Property Holdings Llc

Inventors

• Nelson Kimberly
• Retsina Theodora
• Hill Lee

Classifications

• D21C5/00

  Other processes for obtaining cellulose, e.g. cooking cotton linters (obtaining fibres for spinning D01C); {Processes characterised by the choice of cellulose-containing starting materials} · CPC title

• D21C9/10

  Bleaching {; Apparatus therefor} · CPC title

• D21C9/08

  Removal of fats, resins, pitch or waxes; {Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching (fats, waxes C11B; natural resins C09F1/00; hemicellulose C08B37/14; purification by mechanical means D21D5/00)} · CPC title

• D21B1/00

  Fibrous raw materials or their mechanical treatment (pretreatment of the finely-divided materials before digesting D21C1/00; methods of beating or refining pulp D21D1/00; purification of the pulp suspension by mechanical means D21D5/00) · CPC title

• D21C5/005 Primary

  Treatment of cellulose-containing material with microorganisms or enzymes · CPC title