Method for treatment of biomass
View Patent ↗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).
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.