Low temperature and efficient fractionation of lignocellulosic biomass using recyclable organic solid acids

Patent metadata

Field	Value
Publication number	US-10494489-B2
Application number	US-201916356327-A
Country	US
Kind code	B2
Filing date	Mar 18, 2019
Priority date	Jan 30, 2017
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

Methods of fractionating lignocellulosic biomass using hydrotropic solid organic acids are provided. Also provided are methods of forming lignin particles, furans, sugars, and/or lignocellulosic micro- and nanofibrils from the liquid and solid fractions produced by fractionation process. The fractionation can be carried out at low temperatures with short reaction times.

First claim

What is claimed is:

1. A method for treating lignocellulosic biomass, the method comprising:
dispersing a lignocellulosic biomass in an aqueous solution comprising a hydrotropic solid organic acid, wherein the concentration of the hydrotropic solid organic acid in the solution is higher than its minimal hydrotrope concentration;
maintaining the solution at a temperature and for a time sufficient to dissolve at least 10 wt. % of the lignin in the lignocellulosic biomass; and
separating the solution and the dispersed lignocellulosic biomass into a spent acid solution comprising dissolved lignin and a water-insoluble cellulose-rich solids fraction comprising water-insoluble lignocellulosic solid residues.

2. The method of claim 1 , wherein the temperature is no greater than 100° C. and the time is no greater than 300 minutes.

3. The method of claim 1 , wherein the lignocellulosic biomass comprises wood chips, milled wood, commercial technical lignin, or a combination thereof.

4. The method of claim 1 , wherein the lignocellulosic biomass is a hardwood and at least 10 wt. % of the lignin in the hardwood is dissolved.

5. The method of claim 1 , wherein the lignocellulosic biomass is softwood and at least 10 wt. % of the lignin in the softwood is dissolved.

6. The method of claim 1 , wherein the lignocellulosic biomass is commercial technical lignin and the amount of the technical lignin dissolved is at least 2 g/100 g solution.

7. The method of claim 1 , further comprising fibrillating the lignocellulosic biomass prior to dispersing the lignocellulosic biomass in the aqueous solution comprising the hydrotropic solid organic acid.

8. The method of claim 1 , further comprising precipitating lignin nanoparticles from the spent acid solution.

9. The method of claim 1 , further comprising converting sugars dissolved in the spent acid solution into furans and separating the furans from the spent acid solution.

10. The method of claim 1 , further comprising mechanically fibrillating the lignocellulosic solid residues to form lignocellulosic microfibrils, lignocellulosic nanofibrils, or a combination thereof.

11. The method of claim 10 , wherein the water-insoluble cellulose-rich solids fraction comprises lignocellulosic solid residues and lignocellulosic nanocrystals.

12. The method of claim 10 , further comprising separating the lignocellulosic solid residues from the lignocellulosic nanocrystals.

13. The method of claim 1 , further comprising converting the water-insoluble lignocellulosic solid residues into sugars via hydrolysis using enzymes or chemicals.

14. The method of claim 1 , further comprising recycling the hydrotropic solid organic acid in the spent acid solution back into the aqueous solution comprising the dispersed lignocellulosic biomass.

Assignees

• Us Agriculture

Inventors

• Zhu Junyong
• Chen Liheng
• Gleisner Roland

Classifications

• D21C3/003

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

• D21C3/04

  with acids, acid salts or acid anhydrides {(D21C3/003 and D21C3/222 take precedence)} · CPC title

• C08H8/00 Primary

  Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} · CPC title

• D21H11/18

  Highly hydrated, swollen or fibrillatable fibres · CPC title

• C12P19/00

  Preparation of compounds containing saccharide radicals (ketoaldonic acids C12P7/58) · CPC title