Product management in biological conversion processes

Patent metadata

Field	Value
Publication number	US-10252183-B2
Application number	US-201715424413-A
Country	US
Kind code	B2
Filing date	Feb 3, 2017
Priority date	Feb 4, 2016
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

Improvements in biological conversion processes and associated apparatuses are disclosed for the generation of useful end products such as ethanol, through metabolic pathways of C1-fixing bacteria that utilize, as a nutrient, a C1-carbon source from a C1-containing substrate such as an industrial waste gas. Particular aspects of the disclosure relate to the downstream recovery of ethanol and/or isopropanol from bleed and permeate streams and more particularly to performing such recovery with improved efficiency that can advantageously reduce capital (e.g., equipment) and/or operating (e.g., utility) costs.

First claim

The invention claimed is:

1. A biological conversion process comprising:
a. feeding a substrate to a bioreactor system comprising at least a first bioreactor including a culture medium and a bacterium to metabolize a carbon source in the substrate and produce at least one fermentation product;
b. withdrawing from the bioreactor system a filtered permeate;
c. withdrawing from the bioreactor system a bleed stream comprising bacterium;
d. feeding at least a portion of the permeate stream to a high pressure separator;
e. feeding at least a portion of the bleed stream to a low pressure separator.

2. The process of claim 1 , further comprising, blending at least a second portion of the permeate stream with the bleed stream to provide a combined stream, and feeding at least a portion of the combined stream to the low pressure separator.

3. The process of claim 1 , wherein the high pressure separator and the low pressure separator are a high pressure distillation column and a low pressure distillation column, respectively.

4. The process of claim 1 , wherein the high pressure separator has an absolute pressure in the range from about 150 kPa to about 650 kPa.

5. The process of claim 1 , wherein the low pressure separator has a vacuum pressure.

6. The process of claim 1 , wherein the bleed stream and permeate stream are both liquid products obtained from a subsequent bioreactor, disposed downstream of the first bioreactor.

7. The process of claim 1 , further comprising (i) withdrawing, from the low pressure separator, a low pressure separator overhead enriched in a fermentation product, relative to the bleed stream; and (ii) withdrawing, from the high pressure separator, a high pressure separator overhead and a high pressure separator bottoms, wherein the high pressure separator overhead is enriched in fermentation product.

8. The process of claim 7 , wherein the low pressure separator overhead comprises the fermentation product separated from the bleed stream.

9. The process of claim 8 , wherein the fermentation product contained in both the low pressure separator overhead and high pressure separator overhead represents a net fermentation product productivity of the bioreactor system.

10. The process of claim 9 , wherein the fermentation product is ethanol, and the net ethanol productivity is at least 55 grams/day, per liter of bioreactor volume.

11. The process of claim 7 , further comprising withdrawing, from the low pressure separator, a low pressure separator bottoms.

12. The process of claim 7 , wherein one or more of (i) the low pressure separator overhead, in addition to a low pressure separator overhead reflux portion, are separated from a low pressure separator vapor outlet stream withdrawn from the low pressure separator, (ii) a low pressure separator bottoms, in addition to a low pressure separator boiler portion, are separated from a low pressure separator liquid outlet stream withdrawn from the low pressure separator, (iii) the high pressure separator overhead, in addition to a high pressure separator overhead reflux portion, are separated from a high pressure separator vapor outlet stream withdrawn from the high pressure separator, and (iv) the high pressure separator bottoms, in addition to a high pressure separator boilup portion, are separated from a high pressure separator liquid outlet stream withdrawn from the high pressure separator.

13. The process of claim 12 , wherein one or more of (i) the low pressure separator vapor outlet stream is fed to a low pressure separator condenser to condense at least a portion thereof, return the low pressure separator overhead reflux portion to the low pressure separator, and recover low pressure separator condenser heat, (ii) the low pressure separator liquid outlet stream is fed to a low pressure separator reboiler to vaporize at least a portion thereof, return the low pressure separator liquid reflux portion to the low pressure separator, and consume low pressure separator reboiler heat, (iii) the high pressure separator vapor outlet stream is fed to a high pressure separator condenser to condense at least a portion thereof, return the high pressure separator overhead reflux portion to the high pressure separator, and recover high pressure separator condenser heat, and (iv) the high pressure separator liquid outlet stream is fed to a high pressure separator reboiler to vaporize at least a portion thereof, return the high pressure high liquid reflux portion to the high pressure separator, and consume high pressure separator reboiler heat.

14. The process of claim 13 , wherein at least a portion of the high pressure separator condenser heat is consumed as low pressure separator reboiler heat.

15. The process of claim 12 , wherein the low pressure separator liquid outlet stream is fed to a low pressure separator reboiler to vaporize portions thereof, return the low pressure separator liquid reflux portion to the low pressure separator, and consume low pressure separator reboiler heat.

16. The process of claim 15 , wherein at least a portion of a high pressure separator condenser heat is consumed as low pressure separator reboiler heat.

17. The process of claim 11 , further comprising recycling at least a portion of the high pressure separator bottoms and/or at least a portion of the low pressure separator bottoms to the bioreactor system.

18. The process of claim 1 , wherein the substrate is a C1-containing substrate, the bacterium is a C1-fixing bacterium, and the at least one fermentation product is selected from the group consisting of ethanol, isopropanol and mixtures thereof.

19. The process of claim 1 additionally comprising the step of partitioning the permeate stream into at least a first permeate portion and a second permeate portion and feeding at least a portion of the first permeate stream portion to a high pressure separator and feeding the second permeate portion to a low pressure separator.

20. The process of claim 19 , wherein, in the step of partitioning, a flow rate of the second permeate portion is adjusted at least in part based on a flow rate of the bleed stream.

21. The process of claim 2 , further comprising (i) withdrawing, from the low pressure separator, a low pressure separator overhead enriched in a fermentation product, relative to the bleed stream; and (ii) withdrawing, from the high pressure separator, a high pressure separator overhead and a high pressure separator bottoms, wherein the high pressure separator overhead is enriched in fermentation product.

22. The process of claim 21 , wherein the low pressure separator overhead comprises fermentation product separated from both the second portion of the permeate stream and the bleed stream.

23. The process of claim 22 , wherein fermentation product contained in both the low pressure separator overhead and high pressure separator overhead represents a net fermentation product productivity of the bioreactor system.

24. The process of claim 23 , wherein the fermentation product is ethanol, and the net ethanol productivity is at least 55 grams/day, per liter of bioreactor volume.

Assignees

• Lanzatech New Zealand Ltd

Inventors

• Schultz Michael Anthony
• Raiser Thomas Ewald
• Brenc Rachel Jane

Classifications

• B01D3/10

  Vacuum distillation (B01D3/12 takes precedence) · CPC title

• B01D3/007

  Energy recuperation; Heat pumps · CPC title

• C12P7/065

  with microorganisms other than yeasts · CPC title

• C12P7/04

  acyclic · CPC title

• B01D61/14

  Ultrafiltration; Microfiltration · CPC title