Separation of lignin and sugars from biomass pre-treatment liquors

Patent metadata

Field	Value
Publication number	US-10793927-B2
Application number	US-201615550288-A
Country	US
Kind code	B2
Filing date	Feb 16, 2016
Priority date	Feb 16, 2015
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

The invention relates to an improved process for separating lignin and monomeric sugars from a liquor comprising lignin and monomeric sugars in a solvent mixture of water and at least one organic solvent, which employs membrane filtration techniques such as nanofiltration and selective water removal, preferably by permeation through a membrane which is selective for water molecules. The invention further relates to a modular system for executing the process according to the invention. The process and system according to the invention are particularly suitable to be incorporated with pre-treatment of lignocellulosic biomass, in particular by organosolv fractionation or solvolysis.

First claim

The invention claimed is:

1. A process for separating lignin and monomeric sugars from a biomass pre-treatment liquor comprising lignin and monomeric sugars in a solvent mixture comprising water and an organic solvent, the process comprising:
(a) subjecting the liquor to nanofiltration over a membrane capable of retaining lignin and permeating monomeric sugars; and
(b) subjecting a permeate originating from step (a) to selective water removal to obtain a suspension comprising precipitated monomeric sugars;
(c) precipitating lignin from a retentate originating from step (a), and
(d) isolating precipitated monomeric sugars from the suspension of step (b).

2. The process according to claim 1 , wherein the liquor is an organosolv liquor or a solvolysis liquor.

3. The process according to claim 1 , wherein the liquor is an organosolv liquor.

4. The process according to claim 2 , wherein the organosolv liquor is obtained by subjecting a lignocellulosic biomass to organosolv prior to step (a).

5. The process according to claim 4 , wherein the organosolv is performed using a ketone organic solvent.

6. The process according to claim 5 , wherein the ketone organic solvent is acetone.

7. The process according to claim 1 , wherein the liquor has a temperature of 100 - 280° C. at the beginning of step (a).

8. The process according to claim 1 , wherein the nanofiltration membrane has a molecular weight cut-off of 200 - 2500 Da.

9. The process according to claim 8 , wherein the nanofiltration membrane has a molecular weight cut-off of 300 - 2000 Da.

10. The process according to claim 1 , wherein the selective water removal is accomplished by selective permeation using a membrane selective for permeation of water molecules.

11. The process according to claim 10 , wherein the selective permeation is accomplished by vapour permeation.

12. The process according to claim 10 , wherein the membrane selective for permeation of water molecules comprises organosilane moieties represented by Si p O q ((CH 2 ) n ) r , wherein n=1−7, p=1.6 −2.4, q =2.5−3.5, and r =0.6 −1.4.

13. The process according to claim 1 , which does not comprise active cooling and/or heating a solution or suspension.

14. The process according to claim 1 , which does not comprise a distillation step.

Assignees

• Stichting Energieonderzoek Centrum Nederland
• TNO

Inventors

• Van Tuel Marc Matheus Antonius
• Huijgen Wouter Johannes Joseph
• Van Veen Henk Martin

Classifications

• Y02E50/10

  Biofuels, e.g. bio-diesel · CPC title

• C07G1/00 Primary

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

• B01D71/5222

  Polyetherketone, polyetheretherketone, or polyaryletherketone · CPC title

• C08H6/00

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

• C08L97/005

  Lignin · CPC title