Lignin extraction from lignocellulosics

Patent metadata

Field	Value
Publication number	US-9303127-B2
Application number	US-201314015727-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Aug 31, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

The present invention is directed to a method to extract lignin from lignocellulosic biomass using lactic acid.

First claim

The invention claimed is:

1. A method of extracting lignin from lignocellulosic biomass, the method comprising:
comminuting the lignocellulosic biomass to form a comminuted biomass;
providing an adjusted lactic acid solution, wherein a pH of a lactic acid solution is adjusted to between about 4 and 9 with a basic solution, wherein the basic solution comprises sodium hydroxide, calcium hydroxide or potassium hydroxide;
adding the adjusted lactic acid solution to the comminuted biomass to form a prepared biomass; and
extracting lignin from the prepared biomass.

2. The method of claim 1 , wherein the extracting lignin occurs at a temperature between about 0° C. and about 75° C.

3. The method of claim 1 , wherein the extracting lignin occurs at a temperature of about 25° C.

4. The method of claim 1 , wherein the extracting lignin occurs at a pressure between about 1 atm and about 200 atms.

5. The method of claim 1 , wherein the biomass is comminuted in the presence of water at a specified ratio of water to the lignocellulosic biomass ranging from about 0.1 to 1.0 up to 10.0 to 1.0.

6. The method of claim 5 wherein the specified ratio of water to biomass exceeds about 1:about 1.

7. The method of claim 5 , wherein the specified ratio of water to biomass is between about 2:about 1 and about 6:about 1.

8. The method of claim 1 , wherein a ratio of the adjusted lactic acid solution to the comminuted biomass is between about 1:about 1 and about 3.4:about 1.

9. The method of claim 1 , wherein the lignocellulosic biomass is at least one of a corn stover, a sugarcane, straw, a saw mill product, a paper mill product, a wood, a switch grass, an elephant grass and combinations thereof.

10. The method of claim 9 , wherein the lignocellulosic biomass is corn stover.

11. The method of claim 1 , wherein the comminuting is at least one of a cutting, a chopping, a grinding, a crushing, a milling, a micronizing, a triturating and combinations thereof.

12. A method of extracting lignin, the method comprising:
mixing a lignocellulosic biomass with water;
comminuting the lignocellulosic biomass to form a comminuted biomass;
providing an adjusted lactic acid solution, wherein a pH of the adjusted lactic acid solution is adjusted to between about 4 and 9 with a basic solution, wherein the basic solution comprises sodium hydroxide, calcium hydroxide or potassium hydroxide;
mixing the comminuted biomass with the adjusted lactic acid solution to form a prepared biomass; and
extracting lignin from the prepared biomass.

13. The method of claim 12 , wherein the extraction occurs at a temperature between about 0° C. and about 500° C.

14. The method of claim 12 , wherein the extraction occurs at a pressure between about 1 atm and about 200 atms.

15. The method of claim 12 , wherein the adjusted lactic acid solution further comprises ethanol and water.

16. The method of claim 12 , wherein the lignocellulosic biomass is comminuted in the presence of water at a specified ratio of water to the lignocellulosic biomass ranging from about 0.1:about 1.0 to about 10.0:about 1.0.

17. The method of claim 16 wherein the specified ratio of water to the lignocellulosic biomass exceeds about 1:about 1.

18. The method of claim 12 , wherein the extracting lignin occurs at a temperature between about 0° C. and about 75° C.

19. A method of extracting lignin, the method comprising:
comminuting a lignocellulosic biomass to form a comminuted biomass;
mixing the comminuted biomass with an adjusted lactic acid solution to form a prepared biomass, wherein a pH of the adjusted lactic acid solution has been adjusted to between about 4 to about 9 with a basic solution, wherein the basic solution comprises sodium hydroxide, calcium hydroxide or potassium hydroxide; and
extracting lignin from the prepared biomass.

20. The method of claim 19 , wherein the basic solution comprises sodium hydroxide.

Assignees

• Dorgan John R
• Eyser Michael Paul
• Perbix Clayton
• Colorado School Of Mines

Inventors

• Dorgan John R
• Eyser Michael Paul
• Perbix Clayton

Classifications

• C08L97/005

  Lignin · CPC title

• D21C3/02

  with inorganic bases or alkaline reacting compounds, e.g. sulfate processes · 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

• C08H6/00

  Macromolecular compounds derived from lignin, e.g. tannins, humic acids · CPC title