MANAGEMENT OF ETHANOL CONCENTRATION DURING SYNGAS FERMENTATION

• US 20130149693A1
• Filed: 10/25/2012
• Published: 06/13/2013
• Est. Priority Date: 12/12/2011
• Status: Active Application

• Current Assignee: Jupeng Bio (HK) Limited
• Original Assignee: INEOS Bio SA
• Inventors: Senaratne, Ryan, Liu, Song
• Application Number:
  US13/660,518
• Publication Number:
  US 20130149693A1
• Time in Patent Office: Days
• US Class Current: 435/3
• CPC Class Codes: C12P 7/065 with microorganisms other than yeasts
• CPC Class Codes: C12P 7/08 produced as by-product or from waste or cellulosic material substrate
• CPC Class Codes: C12P 7/14 Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A process is provided for management of ethanol concentration during syngas fermentation. A process for fermentation of syngas includes inoculating a medium to provide an inoculated medium. Inoculated medium is contacted with syngas and cells and medium are removed and separated to provide concentrated cells and permeate. Ethanol is separated from the permeate to provide ethanol and a reduced ethanol aqueous stream. The reduced ethanol aqueous stream is returned to the fermentation.

Claims

1. A process for fermentation of syngas comprising:

contacting syngas with an inoculated medium having a cell density of at least about 0.1 grams per liter;

removing cells and medium from the fermentation and separating the removed cells and medium to provide concentrated cells and permeate;

separating ethanol from the permeate to provide ethanol and a reduced ethanol aqueous stream; and

providing the reduced ethanol aqueous stream to the fermentation;

wherein a ratio of a rate of providing the reduced ethanol aqueous stream to the fermentation to a rate of removing the cells and medium from the fermentation is about 0.5 to about 25.

2. The process of claim 1 wherein cells and medium are removed upon reaching an ethanol concentration of more than about 10 g/L in the fermentation.

3. The process of claim 1 wherein cells and medium are removed upon reaching a cell density of about 0.5 grams per liter or more.

4. The process of claim 1 wherein an ethanol concentration of more than about 10 g/L is maintained in the fermentation.

5. The process of claim 1 wherein permeate is transferred to a permeate holding tank.

6. The process of claim 5 wherein permeate is transferred to a distillation column.

7. The process of claim 6 wherein prior to distillation, the permeate is preheated by heat exchange with the reduced ethanol aqueous stream.

8. The process of claim 6 wherein prior to providing the reduced ethanol aqueous stream to the fermentation, the reduced ethanol aqueous stream is used to scrub fermenter off-gas.

9. The process of claim 1 wherein the reduced ethanol aqueous stream comprises acetic acid.

10. The process of claim 6 wherein CO₂ is removed from the permeate prior to distillation.

11. The process of claim 1 wherein fusel oil is removed from a distillation column at a side draw.

12. A process for fermentation of syngas comprising:

contacting syngas with an inoculated medium having a cell density of at least about 0.1 grams per liter;

upon reaching a ethanol concentration of more than about 10 g/L in the fermentation, removing cells and medium and separating the cells and medium to provide concentrated cells and permeate;

transferring permeate to a permeate holding tank;

transferring permeate from the permeate holding tank to a distillation column effective for separating ethanol from permeate to provide ethanol and a reduced ethanol aqueous stream; and

providing an a reduced ethanol aqueous stream to the fermentation;

wherein a ratio of a rate of providing the reduced ethanol aqueous stream to the fermentation to a rate of removing the cells and medium from the fermentation is about 0.5 to about 25.

13. The process of claim 12 wherein cells and medium are removed upon reaching a cell density of about 0.5 grams per liter or more.

14. The process of claim 12 wherein prior to distillation, the permeate is preheated by heat exchange with the reduced ethanol aqueous stream.

15. The process of claim 12 wherein prior to providing the reduced ethanol aqueous stream to the fermentation, the reduced ethanol aqueous stream is used to scrub fermentor off-gas.

16. The process of claim 12 wherein the reduced ethanol aqueous stream comprises acetic acid.

17. The process of claim 12 wherein CO₂ is removed from the permeate prior to distillation.

18. The process of claim 12 wherein fusel oil is removed from a distillation column at a side draw.

19. A process for fermentation of syngas comprising:

inoculating a medium to provide an inoculated medium having cell density of at least about 0.1 grams per liter;

contacting syngas with the inoculated medium;

removing cells and medium from the fermentation and separating the cells and medium to provide concentrated cells and permeate;

separating ethanol from the permeate to provide ethanol and a reduced ethanol aqueous stream; and

providing the reduced ethanol aqueous stream to the fermentation;

wherein a rate of providing the reduced ethanol aqueous stream to the fermentation and a rate of removing the cells and medium from the fermentation is effective for providing a growth factor of at least about 0.01 grams/gram/hour.

20. The process of claim 19 wherein cells and medium are removed upon reaching an ethanol concentration of more than about 10 g/L in the fermentation.

21. The process of claim 19 wherein cells and medium are removed upon reaching a cell density of about 0.5 grams per liter or more.

22. The process of claim 19 wherein permeate is transferred to a permeate holding tank.

23. The process of claim 22 wherein permeate is transferred to a distillation column.

24. The process of claim 23 wherein prior to distillation, the permeate is preheated by heat exchange with the reduced ethanol aqueous stream.

25. The process of claim 19 wherein prior to providing the reduced ethanol aqueous stream to the fermentation, the reduced ethanol aqueous stream is used to scrub fermentor off-gas.

26. The process of claim 19 wherein the reduced ethanol aqueous stream comprises acetic acid.

27. The process of claim 19 wherein CO₂ is removed from the permeate prior to distillation.

28. The process of claim 19 wherein fusel oil is removed from a distillation column at a side draw.

29. A process for fermentation of syngas comprising:

inoculating a medium to provide an inoculated medium having cell density of at least about 0.1 grams per liter;

contacting syngas with the inoculated medium;

measuring a growth factor and providing an aqueous stream to the fermentation when the growth factor is less than a critical growth factor.

30. The process of claim 29 wherein the aqueous stream comprises a reduced ethanol aqueous stream, wherein

said reduced ethanol aqueous stream is obtained by:

removing cells and medium from the fermentation and separating the cells and medium to provide concentrated cells and permeate;

separating ethanol from the permeate to provide ethanol and the reduced ethanol aqueous stream.

31. A process for fermentation of syngas comprising:

inoculating a medium to provide an inoculated medium having cell density of at least about 0.1 grams per liter;

contacting syngas with the inoculated medium;

measuring a growth factor and providing an aqueous stream to the fermentation in an amount effective for maintaining a growth factor above a critical growth factor.

32. The process of claim 31 wherein the aqueous stream comprises a reduced ethanol aqueous stream, wherein

said reduced ethanol aqueous stream is obtained by:

removing cells and medium from the fermentation and separating the cells and medium to provide concentrated cells and permeate;

separating ethanol from the permeate to provide ethanol and the reduced ethanol aqueous stream.

33. A high productivity process for fermentation of syngas comprising:

contacting syngas with an inoculated medium having a cell density of at least about 0.1 grams per liter;

removing cells and medium from the fermentation and separating the removed cells and medium to provide concentrated cells and permeate;

separating ethanol from the permeate to provide ethanol and a reduced ethanol aqueous stream; and

providing the reduced ethanol aqueous stream to the fermentation;

wherein a ratio of a rate of providing the reduced ethanol aqueous stream to a rate of removing the cells and medium is about 0.5 to about 25,

wherein the process is effective for maintaining an STY of at least about 60 g/(L·

day).