Method to separate lignin-rich solid phase from acidic biomass suspension at an acidic pH

• US 9,751,781 B2
• Filed: 03/15/2013
• Issued: 09/05/2017
• Est. Priority Date: 03/20/2012
• Status: Active Grant

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York)
• Inventors: Yasarla, Lakshmi Rakesh Kumar, Ramarao, Bandaru V., Amidon, Thomas
• Primary Examiner(s): Ware, Debbie K
• Assistant Examiner(s): Srivastava, Kailash C
• Application Number:
  US14/387,169
• Publication Number:
  US 20150044733A1
• Time in Patent Office: 1,635 Days
• Field of Search: 134 13, 210201, 210202, 210225, 210725, 210738, 435105
• CPC Class Codes: B01D 21/0012 Settling tanks making use of filters, e.g. by floating layers of particulate material
• CPC Class Codes: B01D 21/01 using flocculating agents for purifying water C02F1/52; for liquid radioactive waste G21F9/10
• CPC Class Codes: B01D 21/262 by using a centrifuge
• CPC Class Codes: B01D 36/045 Combination of filters with centrifugal separation devices
• CPC Class Codes: C02F 1/5272 using specific organic precipitants
• CPC Class Codes: C02F 2001/007 Processes including a sedimentation step
• CPC Class Codes: C02F 2103/26 from the processing of plants or parts thereof
• CPC Class Codes: C07G 1/00 Lignin; Lignin derivatives
• CPC Class Codes: C08H 6/00 Macromolecular compounds derived from lignin, e.g. tannins, humic acids
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C12M 45/04 Phase separators; Separation of non fermentable material; Fractionation
• CPC Class Codes: C12M 45/09 by enzymatic treatment
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source ethanol C12P7/10
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C13K 13/00 Sugars not otherwise provided for in this class
• CPC Class Codes: C13K 13/002 Xylose
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A method of separating a lignin-rich solid phase from a solution suspension, by pretreating a lignocellulosic biomass with a pretreatment fluid having remove soluble components, colloidal material and primarily lignin containing particles; separating the pretreated lignocellulosic biomass from the pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles; flocculating the separated pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles using polyethylene oxide (i.e., PEO) or cationic Poly acrylamide (i.e., CPAM) as a flocculating agent; and filtering the flocculated separated pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles to remove agglomerates.

Claims

1. A method of separating a lignin-rich solid phase from an aqueous suspension comprising a lignocellulosic biomass having an acidic pH and aromatic components, the method comprising:

dividing the aqueous suspension comprising the lignocellulosic biomass having the acidic pH and the aromatic components into a residual lignocellulosic biomass and a suspension comprising soluble components having colloidal material and primarily lignin containing particles, said suspension having a pH less than about 4, using a pretreatment fluid;

flocculating said suspension using a sufficient amount of polyethylene oxide (PEO) as a flocculating agent, substantially without added cofactors;

adding to said suspension a precipitated calcium carbonate to raise the pH to between about 5 to 7.5; and

separating the flocculated suspension to remove agglomerates to achieve a reduction in turbidity of about 99.5%.

2. The method according to claim 1, wherein said dividing comprises at least one method selected from the group consisting of sedimentation, centrifugation, and microfiltration.

3. The method according to claim 1, wherein said pretreatment fluid comprises a hot water extraction fluid.

4. The method according to claim 1, wherein said flocculating is conducted at a temperature of about 21.5°

C. to about 25°

C.

5. The method according to claim 1, further comprising fermenting a solution resulting after separating the flocculated suspension to remove agglomerates.

6. The method according to claim 1, wherein said separating comprises filtering through a filter having a pore size of less than about 10 microns.

7. The method according to claim 1, wherein said separating comprises filtering through at least one of a ceramic filter and a cloth filter.

8. The method according to claim 1, wherein the flocculating is performed for a sufficient time of less than about 2 hours to form agglomerates separable from the flocculated suspension to achieve the reduction in turbidity of about 99.5%.

9. The method according to claim 1, wherein the precipitated calcium carbonate is limited to an amount that does not substantially increase turbidity of the suspension.

10. A method for treating lignocellulosic biomass comprising:

treating the lignocellulosic biomass with an extractant to extract a suspension comprising soluble components having colloidal material and primarily lignin containing particles from the lignocellulosic biomass, yielding a residual biomass and the suspension having a pH less than about 4;

separating the suspension from the residual biomass;

adding a flocculating agent to the suspension to form a flocculated suspension, wherein the flocculating agent comprises polyethylene oxide (PEO) in an amount sufficient to achieve a 99.5% reduction in turbidity after separation;

adding to the suspension a precipitated calcium carbonate to raise the pH between about 5 and 7.5; and

separating a flocculated portion of the flocculated suspension from a non-flocculated portion of the flocculated suspension to produce a fermentable solution from the lignocellulosic biomass.

11. The method according to claim 10, wherein the extractant comprises hot water.

12. The method according to claim 10, wherein the suspension is separated from the residual biomass with a separation device which comprises at least one of a filter, a sedimentation tank, and a centrifuge.

13. A method of separating a lignin-rich solid phase from a suspension comprising:

dividing a lignocellulosic biomass into a residual lignocellulosic biomass and a suspension comprising soluble components having colloidal material and primarily lignin containing particles, the suspension having a pH less than about 4, using a pretreatment fluid;

treating the suspension with a polymer flocculating agent comprising a sufficient amount of polyethylene oxide (PEO) and precipitated calcium carbonate to raise the pH to between about 5 and 7.5 and said polymer flocculating agent, being substantially without additional cofactors; and

separating the flocculated suspension to remove agglomerates to achieve a reduction in turbidity of about 99.5%.

14. The method according to claim 13, wherein said dividing comprises at least one method selected from the group consisting of sedimentation, centrifugation, and microfiltration.

15. The method according to claim 13, wherein said suspension comprises an aqueous suspension.

16. The method according to claim 13, wherein said treating is conducted at a temperature of about 21.5°

C. to about 25°

C.

17. The method according to claim 13, further comprising microbially processing a non-agglomerated portion of the flocculated suspension.

18. The method according to claim 17, wherein said microbially processing comprises fermenting.

19. The method according to claim 13, wherein said separating comprises filtering through a filter having a pore size of less than about 10 microns.

20. The method according to claim 13, wherein said separating comprises filtering through at least one of a ceramic filter and a cloth filter.

21. The method according to claim 13, wherein the treating is performed for less than about 2 hours.

22. The method according to claim 13, wherein said pretreatment fluid comprises a hot water extraction fluid and said treating is conducted at a temperature of about 21.5°

C. to about 25°

C.

23. The method according to claim 13, wherein the precipitated calcium carbonate is limited to an amount that does not substantially increase turbidity of the suspension.