Post-treatment to enhance the enzymatic hydrolysis of pretreated lignocellulosic biomass

• US 9,914,948 B2
• Filed: 03/01/2016
• Issued: 03/13/2018
• Est. Priority Date: 03/04/2015
• Status: Active Grant

• Current Assignee: FPInnovations
• Original Assignee: FPInnovations
• Inventors: Del Rio, Luis Fernando, Wafa Al Dajani, Waleed, Mao, Changbin, Yuan, Zhirun
• Primary Examiner(s): FRONDA, CHRISTIAN L
• Application Number:
  US15/057,642
• Publication Number:
  US 20160257982A1
• Time in Patent Office: 742 Days
• Field of Search: None
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12P 7/16 Butanols
• CPC Class Codes: C12P 7/46 Dicarboxylic acids having four or less carbon atoms, e.g. fumaric acid, maleic acid
• CPC Class Codes: C12P 7/56 Lactic acid
• CPC Class Codes: D06L 4/15 using organic agents
• CPC Class Codes: D21C 5/005 Treatment of cellulose-containing material with microorganisms or enzymes
• CPC Class Codes: D21C 9/166 with peracids
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present disclosure relates to a process for extracting sugars from a pretreated lignocellulosic biomass. This process consists of contacting the pretreated lignocellulosic biomass with low charges of an aqueous peroxy acid (PA) solution to produce a liquid fraction (containing a small amount of lignin and hemicellulose degradation products) and a solid fraction containing cellulose, hemicellulose and lignin. The solid fraction can then be subjected to enzymatic hydrolysis with a variety of cell wall-degrading enzymes to produce a lignin-rich residue and a sugar solution that can be fermented to a variety of (bio)chemicals.

Claims

1. A process for improving the efficiency of the enzymatic hydrolysis of a pre-treated biomass comprising the steps of

a) treating the biomass containing lignin with a swelling agent and an aqueous solution of a peroxy acid (PA) increasing hydrophilicity of the lignin;

and

b) hydrolyzing the lignin-containing biomass.

2. The process of claim 1, wherein the treatment of the pretreated biomass with the aqueous solution of PA produces a liquid fraction and a solid fraction, said solid fraction containing cellulose and lignin with increased hydrophilicity and depending on the pretreatment process may contain hemicelluloses.

3. The process of claim 2, wherein the hydrolysis of the solid fraction with a cellulase or other carbohydrate-degrading enzyme produces a sugar solution and a lignin-rich residue.

4. The process of claim 3, further comprising the step of isolating the sugar solution from the lignin-rich residue.

5. The process of claim 1, further comprising a first step of treating the pretreated biomass with the swelling agent prior to contacting said pretreated biomass with the PA solution.

6. The process of claim 1, wherein the swelling agent is an aqueous solution of sodium carbonate, an aqueous solution of potassium carbonate, an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, or concentrated phosphoric acid.

7. The process of claim 5, wherein the swelling agent is a polar organic solvent.

8. The process of claim 5, wherein the pretreated lignocellulosic biomass is treated with the swelling agent at a temperature from 40°

C. to about 150°

C.

9. The process of claim 3, wherein the solid fraction contains 90-95% of the total lignin present in the pretreated lignocellulosic biomass.

10. The process of claim 2, further comprising the step of separating the solid fraction from the liquid fraction prior to the hydrolysis step.

11. The process of claim 10, wherein the aqueous phase comprises at least one of formic acid, acetic acid, sulphuric acid, a lignin-derived phenolic compounds and hemicellulosic sugars.

12. The process of claim 11 further comprising the step of generating sodium acetate from the acetic acid in the aqueous phase and recycling said sodium acetate as a buffer for the hydrolysis of the solid fraction.

13. The process of claim 11, wherein the solid fraction is further washed with water at a temperature of 20°

C. to about 90°

C. to remove the phenolic compounds and hemicellulosic sugars prior to the hydrolysis step.

14. The process of claim 3, further comprising the step of fermenting the sugar solution with a suitable microorganism.

15. The process of any one of claim 1, further comprising the step of treating the lignin-containing post-treated biomass with a cell-wall degrading enzyme concurrently with the hydrolysis of said lignin-containing post-treated biomass.

16. The process of claim 15, wherein the cell wall-degrading enzyme is at least one of a cellulase, a hemicellulase, a pectinase and a combination thereof.

17. The process of claim 16, wherein the hemicellulase is a xylanase, a mannanase or a galactomannanase.

18. The process of claim 1, wherein the pretreated biomass is derived from corn stover, a bioenergy crop, an agricultural residue, a wood chip, a sawdust, a forest residue, a wheat straw, grasses, a sludge, a byproduct from the paper manufacture or any combination thereof.

19. The process of claim 1, wherein the pretreated biomass was pretreated by the TMP-Bio, organosolv, steam explosion, ammonia fiber explosion (AFEX), mechanical comminution, mechanical pulping, green liquor pretreatment, liquid hot water, SPORL, dilute acid hydrolysis process or a combination thereof.

20. The process of claim 1, wherein the pretreated biomass comprises 10-60% w/w of lignin.