Method to convert mechanical pulp derived waste material into value added cellulose products

Patent metadata

Field	Value
Publication number	US-11486094-B2
Application number	US-201816480315-A
Country	US
Kind code	B2
Filing date	Feb 1, 2018
Priority date	Feb 1, 2017
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

According to an example aspect of the present invention, there is provided a process for the conversion of cellulosic waste material into a recycled cellulose product comprising the steps of cooking the waste material in a cooking liquor to remove lignin from the waste material and provide a delignified pulp, dissolving the delignified pulp in an ionic liquid to provide a spinning dope suitable for dry jet-wet spinning in an ionic liquid solution, and subjecting the spinning dope to a further processing step to provide a recycled cellulose product, said further step selected from the group of spinning cellulose fibers for use in textiles from the solution, extruding a film product for use in packaging, regenerating the dope as a hydrogel and regenerating the dope as an aerogel.

First claim

The invention claimed is:

1. A process for conversion of cellulosic waste material into a recycled cellulose product comprising:
cooking the cellulosic waste material in a cooking liquor to remove lignin from the cellulosic waste material and provide a delignified pulp,
dissolving the delignified pulp in an ionic liquid to provide a spinning dope, and
forming the recycled cellulose product from the spinning dope,
wherein the cooking liquor comprises alkaline glycerol, and
wherein the alkyline glycerol comprises a glycerol to alkaline to cellulosic waste material ratio of 10 to 1.25 to 1 by weight.

2. The process according to claim 1 , wherein the cellulosic waste material is derived from mechanical pulp.

3. The process according to claim 1 , wherein the cellulosic waste material is derived from a member of the group consisting of newspaper, newspaper inserts, directories, books, magazines, catalogues, coupons, posters, and a mixture thereof.

4. The process according to claim 1 , wherein the alkaline component of the alkaline glycerol is selected from the group consisting of KOH and NaOH.

5. The process according to claim 1 , wherein the cooking is carried out at a temperature in the range of 170° C. to 180° C. for a period of from 60 to 180 minutes.

6. The process according to claim 1 , wherein the cooking liquor comprises an alkaline content, and wherein the alkaline content of the cooking liquor comprises 2 to 20 wt % of the cooking liquor.

7. The process according to claim 1 , wherein the delignified pulp comprises from 5 to 10 wt % lignin.

8. The process according to claim 1 , wherein the ionic liquid is a superbase-based ionic liquid.

9. The process according to claim 1 , wherein the ionic liquid is selected from the group consisting of [DBNH][OAc] and [MTBDH][OAc].

10. The process according to claim 1 , wherein the delignified pulp is subjected to an acid treatment to remove ash before dissolving in the ionic liquid.

11. The process according to claim 1 , wherein the delignified pulp has a viscosity of 250-700 mL/g.

12. The process according to claim 1 , wherein the spinning dope has a zero-shear viscosity in the range of 10,000 to 60,000 Pa·s.

13. The process according to claim 1 , wherein the spinning dope has a cross-over point having an angular frequency in the range of 0.2 to 5 s −1 and a dynamic modulus in the range of 1000 to 7000 Pa.

14. The process of claim 1 , wherein said forming step comprises a member selected from the group consisting of:
spinning cellulose fibers from the spinning dope,
extruding a film product from the spinning dope,
regenerating the spinning dope as a hydrogel, and
regenerating the spinning dope as an aerogel.

Assignees

• Aalto Univ Foundation Sr

Inventors

• Sixta Herbert
• Ma Yibo
• Hummel Michael

Classifications

• Y02W30/64

  Paper recycling · CPC title

• D21C9/004

  inorganic compounds · CPC title

• D21C3/003

  with organic compounds (D21C3/20 and D21C3/222 take precedence) · CPC title

• D21C9/005

  organic compounds · CPC title

• D21H13/08 Primary

  from regenerated cellulose · CPC title