Secondary acetate fermentation

Abstract

The disclosure relates to the system comprising a combination of a primary bioreactor with a secondary bioreactor to convert a gaseous stream comprising CO and optionally H2, or CO2 and H2 to at least one target product. Bioreactors may be any combination of aerobic and anaerobic, batch and continuous. The bioreactors comprise fermenting microorganisms that may typically be bacterial or fungal.

1 . A two-stage system for producing at least one target product from a gaseous stream comprising CO and optionally H 2 , or CO 2  and H 2 , the system comprising:
 i. a primary bioreactor comprising a media inlet port, a gas inlet port, a first output conduit connected to an outlet port, and a bleed stream outlet connected to a bleed stream outlet conduit;   ii. a primary separator comprising a first conduit inlet port connected to the output conduit of the primary bioreactor, a first primary permeate stream outlet connected to a primary permeate stream outlet conduit, and a second primary permeate stream outlet connected to a first return conduit, the first return conduit in fluid communication with the primary bioreactor;   iii. a secondary bioreactor, in fluid communication with the bleed stream outlet conduit of the primary bioreactor and the primary permeate stream outlet conduit of the primary separator, the secondary bioreactor comprising, a tail gas stream outlet connected to a tail gas stream conduit, a first output port connected to a first output conduit, and a broth bleed output port connected to a broth bleed conduit;   iv. a secondary separator, comprising a second inlet port in fluid communication with the first output conduit of the secondary bioreactor, a retentate outlet port connected to a retentate return conduit which is in fluid communication with the secondary bioreactor through a retentate inlet port, and a second permeate stream outlet port connected to a second permeate stream conduit comprising the at least one target product; and   v. an oxygen removal unit having a tail gas stream inlet port connected to the tail gas stream outlet conduit of the secondary bioreactor, a CO 2  enriched outlet port connected to a CO 2  enriched conduit in fluid communication with a CO 2  enriched inlet port on the primary bioreactor, and an O 2  enriched stream outlet port connected to an O 2  enriched stream conduit.   
     
     
         2 . The system of  claim 1 , wherein the primary bioreactor comprises a fermentation broth comprising a culture of at least one primary microorganism in a first liquid nutrient medium. 
     
     
         3 . The system of  claim 2 , wherein the at least one primary microorganism comprises an acetogenic bacteria. 
     
     
         4 . The system of  claim 1 , wherein the gas inlet port is configured to supply the gaseous stream to the primary bioreactor. 
     
     
         5 . The system of  claim 1 , wherein the primary permeate stream conduit comprises a primary permeate stream comprising acetate. 
     
     
         6 . The system of  claim 1 , wherein the O 2  enriched stream outlet conduit is in fluid communication with the secondary bioreactor. 
     
     
         7 . The system of  claim 1 , wherein the secondary bioreactor comprises a culture of one or more secondary microorganism in a second liquid nutrient medium. 
     
     
         8 . The system of  claim 7 , wherein the secondary microorganism comprises one or more aerobic microorganism. 
     
     
         9 . The system of  claim 1 , wherein the broth bleed output port is configured to remove fermentation broth from the secondary bioreactor. 
     
     
         10 . The system of  claim 1 , wherein the oxygen removal unit is at least one unit selected from a pressure swing adsorption unit, a membrane separation unit, a scrubber unit using a basic solution, an absorption unit using a solvent, or any combination thereof. 
     
     
         11 . A two-stage system for producing at least one target product from a gaseous stream comprising CO and optionally H 2 , or CO 2  and H 2 , the system comprising:
 i. a primary anaerobic bioreactor comprising a media inlet port, a gas inlet port, and a bleed stream outlet port connected to a bleed stream outlet conduit;   ii. a secondary aerobic bioreactor, comprising an inlet port in fluid communication with the bleed stream outlet conduit of the primary anaerobic bioreactor, an oxygen source inlet port, a second outlet port connected to a second outlet conduit, and a tail gas outlet connected to a tail gas stream conduit;   iii. an oxygen separation unit having a tail gas stream inlet port connected to the tail gas stream conduit, a CO 2  enriched outlet port connected to a CO 2  enriched conduit in fluid communication with the gas inlet port of the primary anaerobic bioreactor, and an O 2  enriched stream outlet port connected to an O 2  enriched stream conduit in fluid communication with the oxygen source inlet port of the secondary aerobic bioreactor; and   iv. an electrolyzer comprising a water stream inlet port, an H 2  stream outlet port connected to an H 2  stream conduit in fluid communication with the gas inlet port of the primary anaerobic bioreactor, and an O 2  stream outlet port connected to an O 2  stream conduit in fluid communication with the oxygen source inlet port of the secondary aerobic bioreactor.   
     
     
         12 . The system of  claim 11  wherein the bleed stream outlet conduit is in fluid communication with a primary separator. 
     
     
         13 . The system of  claim 11  wherein the second outlet conduit is in fluid communication with a secondary separator. 
     
     
         14 . The system of  claim 12  wherein the primary separator comprises a first primary permeate stream outlet connected to a primary permeate stream outlet conduit in fluid communication with the secondary aerobic bioreactor. 
     
     
         15 . The system of  claim 14  wherein the primary separator further comprises a second primary permeate stream outlet connected to a first return conduit in fluid communication with the primary anaerobic bioreactor. 
     
     
         16 . The system of  claim 13  wherein the secondary separator comprises a retentate outlet port connected to a retentate return conduit which is in fluid communication with the secondary bioreactor through a retentate inlet port. 
     
     
         17 . The system of  claim 16  wherein the secondary separator comprises a second permeate stream outlet port connected to a second permeate stream conduit comprising the at least one target product.