Renewable aromatics from lignocellulosic lignin

Patent metadata

Field	Value
Publication number	US-10233292-B2
Application number	US-201314650506-A
Country	US
Kind code	B2
Filing date	Dec 9, 2013
Priority date	Dec 7, 2012
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

The present invention provides novel and improved processes for treating a lignocellulosic biomass or technical lignin using ionic liquids to obtain lignin breakdown products.

First claim

What is claimed is:

1. A method comprising:
(i) contacting a starting material comprising a technical lignin with an ionic liquid to generate a solubilized material for at least about 3 hours at a temperature of at least about 160° C.; and
(ii) extracting low molecular weight or monomeric aromatic lignin compounds from the solubilized material with an extractant, wherein the extractant is a nonpolar solvent; and
(iii) optionally separating the extracted low molecular weight or monomeric aromatic lignin compounds resulting from step (ii) from the extractant.

2. The method of claim 1 , wherein step (ii) comprises
(a) precipitating a fraction of the solubilized material with a polar solvent to generate a precipitated fraction and a supernatant;
(b) separating the precipitated fraction from the supernatant; and
(c) extracting the low molecular weight or monomeric aromatic lignin compounds from the supernatant via liquid-liquid extraction with the nonpolar solvent.

3. The method of claim 2 , wherein the polar solvent of step (a) is selected from the group consisting of water, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, heptanol, octanol, or isooctanol.

4. The method of claim 1 , wherein the extractant is selected from the group consisting of benzene, toluene, pentane, hexane, heptane, octane, and isooctane.

5. The method of claim 2 , wherein step (ii) further comprises (d) separating the non-polar solvent from the supernatant.

6. The method of claim 1 , wherein the ionic liquid is water miscible.

7. The method of claim 1 , wherein the ionic liquid is [C 2 mim][OAc].

8. The method of claim 1 , wherein the technical lignin comprises kraft lignin, a lignosulfate, alkali lignin, low sulfonate alkali lignin, or a combination thereof.

9. The method of claim 1 , which comprises step (iii).

10. The method of claim 9 , wherein step (iii) comprises distillation or column fractionation.

11. The method of claim 1 , wherein the extractant is selected from the group consisting of benzene, hexane, and pentane.

12. The method of claim 2 , wherein the extractant is selected from the group consisting of benzene, hexane, and pentane.

Assignees

• Sandia Corp
• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Singh Seema
• Varanasi Patanjali
• Simmons Blake

Classifications

• D21C11/0007

  Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for (volatile compounds obtained by decomposition of spent liquors in order to regenerate them D21C11/125; compounds obtained by fractionating the liquors in order to regenerate them D21C11/0042) · CPC title

• C08L97/005

  Lignin · CPC title

• C08H6/00 Primary

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

• D21C3/20

  with organic solvents {or in solvent environment} · CPC title

• C07G1/00

  Low-molecular-weight derivatives of lignin (high-molecular-weight derivatives of lignin {C08H6/00}) · CPC title