Processes and systems for metabolite production using hydrogen rich C1-containing substrates
The invention is directed to a process for producing one or more fermentation product in a multi-stage process including an inoculation reactor and at least one bioreactor. The inoculation reactor is fed a C1-containing gaseous substrate containing a reduced amount of hydrogen. The hydrogen is reduced to increase the proportion of CO in the C1-containing gaseous substrate being provided to the inoculation reactor. The inoculation reactor ferments the CO-rich C1-containing gaseous substrate and produces an inoculum, which is fed to at least one bioreactor. The bioreactor receives the C1-containing gaseous substrate, which may or may not contain reduced amounts of hydrogen, to produce one or more fermentation product. By providing a CO-rich C1-containing gaseous substrate to the inoculation reactor, both the inoculation reactor and the subsequent bioreactor(s), are able to have increased stability and product selectivity.
1. A process comprising:
a. producing a syngas comprising CO and H 2 ;
b. passing the syngas to a hydrogen separation process to produce a CO-rich gaseous substrate and an H 2 rich gaseous substrate;
c. passing the CO-rich gaseous substrate to an inoculation reactor comprising a culture of at least one C1-fixing microorganism in a liquid nutrient medium;
d. fermenting the CO-rich gaseous substrate to produce an inoculum;
e. passing at least a portion of the inoculum to a bioreactor system, the bioreactor system comprising at least one bioreactor containing a culture of the at least one C1-fixing microorganism of step (c) in a liquid nutrient medium;
f. passing the H 2 rich gaseous substrate to the at least one bioreactor of step (e); and
g. fermenting the H 2 rich gaseous substrate to produce at least one fermentation product.
2. The process of claim 1 , step b, further comprising passing the syngas to a first water gas shift reactor, wherein at least a portion of the CO is reacted with water to produce CO 2 and H 2 , and then passing a first exit gas stream comprising CO 2 and H 2 from the first water gas shift reactor to the hydrogen separation process.
3. The process of claim 2 , further comprising passing the exit gas stream comprising CO 2 and H 2 from the first water gas shift reactor to a second water gas shift reactor and then passing a second exit gas stream from the second water shift reactor to the hydrogen separation process.
4. The process of claim 1 , wherein the hydrogen separation process comprises a membrane separation module.
5. The process of claim 4 , wherein at least a portion of the H 2 rich gaseous substrate from the membrane separation module is passed to a pressure swing adsorption (PSA) reactor to produce a hydrogen stream and a CO and H 2 gaseous substrate which is passed to the bioreactor.
6. The process of claim 1 , wherein the hydrogen separation process is a PSA process.
7. The process of claim 1 , wherein the CO-rich gaseous substrate comprises H 2 at an H 2 :CO molar ratio of less than 1:1.
8. The process of claim 1 , wherein the CO-rich gaseous substrate comprises H 2 at an H 2 :CO molar ratio of less than 0.5:1.
9. The process of claim 1 , wherein the CO-rich gaseous substrate comprises H 2 at an H 2 :CO molar ratio between 0.02:1 to 1:1.
10. The process of claim 1 , wherein the H 2 rich gaseous substrate comprises H 2 at an H 2 :CO molar ratio of at least 1.1:1.
11. The process of claim 1 , wherein the H 2 rich gaseous substrate comprises H 2 at an H 2 :CO molar ratio between 1.1:1 to 6:1.
12. The process of claim 1 , wherein the at least one C1-fixing microorganism is a carboxydotrophic bacterium.
13. The process of claim 12 , wherein the carboxydotrophic bacterium is selected from the group consisting of Moorella, Clostridium, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina , and Desulfotomaculum.
14. The process of claim 13 , wherein the carboxydotrophic bacterium is Clostridium autoethanogenum.
15. The process of claim 1 , wherein the syngas is produced from steam methane reforming, steam naphta reforming, petroleum coke gasification, dry methane reforming, and mixtures thereof.
16. The process of claim 1 , wherein the at least one fermentation product is selected from ethanol, acetate, butanol, butyrate, 2,3-butanediol, 1,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone, ethylene, acetone, isopropanol, lipids, 3-hydroxypropionate, isoprene, fatty acids, 2-butanol, 1,2-propanediol, 1-propanol, monoethylene glycol, isobutene, C6-C14 alcohols, and mixtures thereof.
17. The process of claim 16 , wherein the at least one fermentation product is further converted to at least one component of diesel fuel, jet fuel, gasoline, propylene, nylon 6-6, rubber, and/or resins.
18. The process of claim 1 , wherein the at least one fermentation product is microbial biomass.
19. The process of claim 18 , wherein the microbial biomass is processed to produce at least one component of animal feed.