Process and system for continuous gas fermentation

Patent metadata

Field	Value
Publication number	US-2025092344-A1
Application number	US-202318468083-A
Country	US
Kind code	A1
Filing date	Sep 15, 2023
Priority date	Sep 15, 2023
Publication date	Mar 20, 2025
Grant date	—

Abstract

The disclosure is directed to a process and apparatus for continuous gas fermentation with reduced accumulation of co-products. The disclosure relates to the use of both a vacuum distillation unit and a membrane separator to provide efficient product recovery, cell retention, and water recycling to maximize production of the fermentation products. The disclosure provides for continuous product recovery at an effective rate and minimizes the accumulation of co-products in the fermentation broth while ensuring the retention and viability of the C1-fixing microorganisms.

First claim

1 . A process for continuous gas fermentation comprising:
a. generating, by gas fermentation of a gas stream in a bioreactor, a fermentation broth comprising gas, microbial biomass, at least one product, and at least one co-product; b. passing at least a portion of the fermentation broth to a separator and separating a gas stream from a liquid stream comprising the microbial biomass, the at least one co-product, and the at least one product; c. passing, serially or in parallel, at least a portion of the liquid stream to a vacuum distillation unit and a membrane separation unit; d. separating, in the vacuum distillation unit, a product enriched stream and a microbial biomass and co-product enriched stream; e. separating, in the membrane separation unit, a permeate stream enriched in water and co-product and a retentate stream enriched in microbial biomass; and f. recycling at least a portion of the retentate stream to the bioreactor.

2 . The process of claim 1 further comprising passing to the bioreactor, at least a portion of the microbial biomass and co-product enriched stream, at least a portion of the retentate, or both.

3 . The process of claim 1 further comprising removing as a bleed stream, at least a portion at least a portion of the microbial biomass and co-product enriched stream, at least a portion of the retentate, or both.

4 . The process of claim 1 further comprising passing at least a portion of the permeate stream to a wastewater treatment unit, generating a treated water stream, and passing at least a portion of the treated water stream to the bioreactor.

5 . The process of claim 1 further comprising passing at least a portion of the gas stream to a gas treatment unit and removing at least one contaminant from the gas stream fermenting in the bioreactor.

6 . The process of claim 1 wherein the microbial biomass and co-product enriched stream comprises less than 0.2 wt. % product.

7 . The process of claim 1 wherein the vacuum distillation unit is operated at a pressure in the range of about 40 mbar(a) to about 100 mbar(a).

8 . The process of claim 1 wherein the vacuum distillation unit is operated at a temperature in the range of about 35° C. to about 50° C.

9 . The process of claim 1 , wherein the product is at least one selected from ethanol, acetate, butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), ethylene, acetone, isopropanol, lipids, 3-hydroxypropionate (3-HP), terpenes, terpenoids, isoprene, fatty acids, 2-butanol, 1,2-propanediol, 1 propanol, chorismate-derived products, 3 hydroxybutyrate, and 1,3-butanediol, 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid, isobutylene, adipic acid, 1,3 hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, monoethylene glycol, 2-phenylethanol, ethylene, or any combination thereof.

10 . The process of claim 1 wherein the gas stream comprises at least hydrogen and carbon monoxide wherein at least a portion of the carbon monoxide is generated by conversion of carbon dioxide to carbon monoxide.

11 . The process of claim 10 wherein the conversion of carbon dioxide comprises heating a gas stream comprising carbon-dioxide to a temperature in the range of about 400° C. to about 600° C., contacting with a conversion catalyst, and then cooling the resulting stream comprising carbon monoxide to a temperature in the range of about 35° C. to about 55° C.

12 . The process of claim 10 wherein the conversion employs reverse water gas shift conversion, CO 2 electrolysis conversion, thermo-catalytic conversion, electro-catalytic conversion, partial combustion conversion, plasma conversion, or any combination thereof.

13 . The process of claim 10 wherein the carbon dioxide is generated by steam reforming, electrolysis powered by a renewable power source, or both.

14 . An apparatus for continuous gas fermentation comprising:
a. a bioreactor comprising a bioreactor inlet, at least one recycle inlet, and a fermentation broth outlet; b. a separator in fluid communication with the fermentation broth outlet, the separator comprising a liquid outlet and a gas outlet; c. a vacuum distillation unit and a membrane separator in fluid communication, serially or in parallel, with the separator liquid outlet; d. the vacuum distillation unit comprising an overhead outlet and a bottoms outlet; and e. the membrane separator comprising a permeate outlet and a retentate outlet, the retentate outlet in fluid communication with at least one of the bioreactor recycle inlets.

15 . The apparatus of claim 14 wherein the bottoms outlet is further in fluid communication with at least one of the bioreactor recycle inlets.

16 . The apparatus of claim 14 further comprising a wastewater treatment unit in fluid communication with the permeate outlet and at least one of the bioreactor recycle inlets.

17 . The apparatus of claim 14 further comprising a gas treatment unit in fluid communication with the bioreactor inlet.

18 . The apparatus of claim 14 further comprising a gas treatment unit in fluid communication with both the gas outlet and at least one of the bioreactor recycle inlets.

19 . The apparatus of claim 14 further comprising, in fluid communication the bioreactor inlet, a CO 2 to CO conversion unit selected from a reverse water gas reaction unit, a CO 2 electrolysis unit, a thermo-catalytic conversion unit, an electro-catalytic conversion unit, a partial combustion unit, a plasma conversion unit or any combination thereof.

20 . The apparatus of claim 14 further comprising a bleed conduit in fluid communication with the liquid outlet, retentate outlet, or both.

Assignees

• Lanzatech Inc

Inventors

• Conrado Robert John
• Martin Michael Emerson
• Bromley Jason Carl

Classifications

• C25B1/55

  Photoelectrolysis · CPC title

• C12P7/16

  Butanols · CPC title

• C12M47/10

  Separation or concentration of fermentation products (bioreactors combined with means for distillation or extraction of liquid fuel C12M43/02) · CPC title

• C12P7/06

  Ethanol, i.e. non-beverage · CPC title

• C12M21/04 Primary

  for producing gas, e.g. biogas (digesters for manure with production of biogas A01C3/028, biological treatment of water, waste water or sewage C02F3/00, C02F11/02, preparation of natural gas or syngas C10L3/06, C10L3/10) · CPC title