Method for treatment of biomass

Patent metadata

Field	Value
Publication number	US-9469859-B1
Application number	US-201113209170-A
Country	US
Kind code	B1
Filing date	Aug 12, 2011
Priority date	Aug 12, 2010
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

The subject disclosure relates to a method for producing a fermentation product from biomass that has been pre-treated in a pre-treatment system and separated into a liquid component and a first solids component. The method comprises: (a) treating the liquid component in a filtration system comprising at least one nano-filter to produce a treated liquid component, and to remove an acid from the liquid component; (b) supplying the treated liquid component, a fermenting organism, and agents to a fermentation system; (c) recovering the fermentation product from the fermentation system; and (d) supplying the acid for re-use in the pre-treatment system. In many embodiments, the biomass comprises lignocellulosic material and the liquid component comprises pentose (e.g., xylose).

First claim

What is claimed is:

1. A method for producing a fermentation product from biomass that has been pre-treated in an acid pre-treatment system and separated into a liquid component comprising a first concentration of a pentose and a first amount of at least one acid comprising sulfuric acid, and a first solids component, the method comprising:
(a) treating the liquid component in a filtration system, the treating comprises: contacting a first nano-filter with the liquid component to form a first retentate and a first permeate, wherein the first retentate comprises a second concentration of the pentose that is greater than the first concentration of the pentose and a second amount of the sulfuric acid that is less than the first amount of the sulfuric acid; and supplying water and the first retentate to a second nano-filter to contact the second nano-filter to form a second retentate and a second permeate, wherein the water supplied to the second nano-filter is in addition to the first retentate, wherein the second retentate comprises a third amount of the sulfuric acid that is less than the second amount the sulfuric acid; and
(b) combining the second retentate, a fermenting organism, and agents in a fermentation system that ferments the pentose, the fermenting organism, and the agents into a fermentation product;
(c) recovering the fermentation product from the fermentation system;
(d) removing water from the first permeate and the second permeate to form a concentrated permeate comprising the sulfuric acid, wherein the removing comprises using a reverse osmosis process; and
(e) supplying the concentrated permeate for re-use in the acid pre-treatment system; wherein the biomass comprises lignocellulosic material; and wherein the pentose comprises xylose.

2. The method of claim 1 , wherein the treating comprises treating the liquid component in a filtration system that comprises a one stage filtration system.

3. The method of claim 1 , wherein the treating comprises treating the liquid component in a filtration system that comprises a multiple stage filtration system.

4. The method of claim 3 , wherein the treating comprises:
supplying the liquid component to a first filtration stage to remove a second solids component from the liquid component;
supplying the liquid component to a second filtration stage to remove acids and to concentrate the xylose in the liquid component; and
recovering the treated liquid component from the filtration system.

5. The method of claim 4 , wherein the supplying the liquid component to the first filtration stage comprises supplying the liquid component to a first filtration stage that comprises a filter with a pore size of 0.01 to 20 micrometers.

6. The method of claim 4 , wherein the supplying the liquid component to the second filtration stage comprises supplying the liquid component to a second filtration stage that comprises a nano-filter with a pore size of less than 10 nm.

7. The method of claim 4 , wherein the supplying the liquid component to the second filtration stage comprises supplying the liquid component to a second filtration stage, wherein the second filtration stage comprises:
a first nano-filtration stage; and
a second nano-filtration stage.

8. The method of claim 7 , wherein the supplying the liquid component to the second filtration stage comprises supplying the liquid component to a second filtration stage that comprises a membrane with pores that allow water molecules and acid ions to pass as permeate and retain sugar molecules as retentate.

9. The method of claim 7 , wherein the second nano-filtration stage is configured for diafiltration.

10. The method of claim 9 , wherein the treating comprises adding water to the liquid component in a ratio of about 0:1 to about 1.3:1 before supplying the retentate.

11. The method of claim 7 , wherein the first nano-filtration stage has a permeate flux rate of 1.5 to 35 L/m 2 /h.

12. The method of claim 1 , wherein the treating comprises reducing the concentration of components inhibitory to fermentation in the liquid component, wherein the reducing comprises adjusting at least one pre-treatment condition.

13. The method of claim 1 , wherein the fermenting organism comprises yeast capable of converting xylose to ethanol.

14. The method of claim 13 , wherein the fermenting organism comprises Saccharomyces cerevisiae.

15. The method of claim 13 , wherein at least about 75 percent of the xylose is converted to ethanol.

16. The method of claim 1 , wherein the treating comprises removing acetic acid from the liquid component.

17. The method of claim 16 , wherein the treating comprises removing at least about 60 percent of the acetic acid from the liquid component.

18. The method of claim 1 , wherein the treating comprises removing at least about 40 percent of the sulfuric acid from the liquid component.

19. The method of claim 1 , wherein the treating comprises concentrating the xylose in the liquid component by at least about 1.5 fold.

20. The method of claim 1 , wherein the treating comprises operating the filtration system at a temperature range of about 20° to about 45° C.

21. The method of claim 1 , wherein the biomass comprises at least one of corn cobs, corn plant husks, corn plant leaves, and corn plant stalks.

22. The method of claim 1 , wherein the biomass consists essentially of corn cobs, corn plant husks, corn plant leaves, and corn plant stalks.

23. The method of claim 1 , wherein the liquid component has a pH of about 3 or less.

24. The method of claim 1 , wherein the liquid component has a pH of about 1 to about 2.

25. A method of reducing the concentration of sulfuric acid in a pentose composition derived from a pre-treated biomass comprising:
providing a pre-treated lignocellulosic biomass material, wherein the pre-treated lignocellulosic biomass has been subjected to a sulfuric acid hydrolysis process to hydrolyse hemicellose to provide pentose, and wherein the pre-treated biomass comprises a first liquid component comprising the sulfuric acid and the pentose, and a solids component;
separating the liquid component from the solids component, wherein the liquid component has a first weight ratio of the pentose to the sulfuric acid;
contacting a nano-filter with the liquid component to form a first retentate and a first permeate, wherein the first retentate comprises a second weight ratio of the pentose to the sulfuric acid and wherein the second weight ratio is greater than the first weight ratio;
mixing the first retentate with water to form a second liquid component;
contacting a nano-filter with the second liquid component to form a second retentate and a second permeate, wherein the second retentate comprises a third weight ratio of the pentose to the sulfuric acid and wherein the third weight ratio is greater than the second weight ratio, and fermenting the second retentate into a fermentation product.

Assignees

• Bly Steven T
• Carlson David Charles
• Kwiatkowski Jason Richard
• Poet Res Inc

Inventors

• Bly Steven T
• Carlson David Charles
• Kwiatkowski Jason Richard

Classifications

• B01D61/027

  Nanofiltration · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• C12P2201/00

  Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis · CPC title

• B01D2317/025

  Permeate series · CPC title

• C12P7/10 Primary

  substrate containing cellulosic material · CPC title