Integrated fermentation and electrolysis process
The invention provides schemes for the integration of a fermentation process, with an electrolysis process, and a C1-generating industrial process. In particular, the invention provides process for utilizing electrolysis products, for example H 2 and/or O 2 , to improve the process efficiency of at least one of the fermentation process or the C1-generating industrial process. More particularly, the invention provides a process whereby, H 2 generated by electrolysis is used to improve the substrate efficiency for a fermentation process, and the O 2 generated by the electrolysis process is used to improve the composition of the C1-containing tail gas generated by the C1-generating industrial process.
1. A process for improving carbon capture efficiency in an integrated fermentation and industrial process, wherein the process comprises:
i. passing one or more feedstocks comprising CO 2 to an electrolysis process to produce an electrolysis derived substrate comprising CO and O 2 ;
ii. blending at least a portion of the electrolysis derived substrate with a C1-containing tail gas from an industrial process to provide a blended C1-containing substrate;
iii. passing the blended C1-containing substrate to a bioreactor containing a culture of at least one anaerobic C1-fixing bacterium; and
iv. anaerobically fermenting the culture to produce one or more fermentation products.
2. The process of claim 1 , wherein at least a portion of the O 2 is passed to the industrial process.
3. The process of claim 1 , wherein an exit gas stream is produced by the fermentation, the exit gas comprises CO 2 , and at least a portion of the CO 2 is recycled to the electrolysis process.
4. The process of claim 1 , wherein the electrolysis process requires an energy input, and the energy input is derived from a renewable energy source.
5. The process of claim 1 wherein the industrial process is a partial oxidation process, wherein said partial oxidation process is selected from the group consisting of a Basic oxygen furnace (BOF) reaction; a COREX or FINEX steel making process, a Blast Furnace (BF) process, a ferroalloy process; a titanium dioxide production process and a gasification process.
6. The process of claim 5 , wherein the partial oxidation process is a gasification process, and wherein the gasification process is selected from the group consisting of a municipal solid waste gasification process, a biomass gasification process, a pet coke gasification process and a coal gasification process.
7. The process of claim 1 wherein the industrial process comprises a complete oxidation process selected from the group consisting of cement production processes, natural gas power plants, and coal fired power plants.
8. The process of claim 1 , wherein the C1-containing tail gas comprises CO, CO 2 and H 2 .
9. The process of claim 1 , wherein the blended C1-containing substrate comprises CO.
10. The process of claim 9 , wherein the blended C1-containing substrate further comprises at least one component selected from the group consisting of CO 2 , H 2 , CH 4 .
11. The process of claim 1 , wherein the C1 fixing bacteria are selected from the genus Clostridium.
12. The process of claim 11 , wherein the at least one C1 fixing bacterium is selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii , and Clostridium ragsdalei.
13. The process of claim 2 , wherein a portion of the C1-containing tail gas is blended with a portion of the oxygen from the electrolysis unit to match the oxygen richness required for the feed to the industrial process.
14. The process of claim 1 , wherein the at least one fermentation product is selected from the group consisting of ethanol, acetate, butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone, ethylene, acetone, isopropanol, lipids, 3-hydroxypropionate, isoprene, fatty acids, 2-butanol, 1,2-propanediol, and 1-propanol.
15. An integrated system comprising;
i. an electrolyser for producing an electrolysis derived substrate comprising CO and O 2 ;
ii. an industrial process zone, utilizing at least a portion of an electrolysis derived substrate of (i) and generating C1-containing tail gas;
iii. an anaerobic fermentation zone producing at least one fermentation product by anaerobic fermentation of at least a portion of the industrial waste gas of (ii) by an anaerobic C1-fixing bacteria.
16. The system of claim 15 , wherein the system further comprises a blending unit, for blending a portion of an electrolysis derived substrate from the electrolysis unit with at least a portion of the C1-containing tail gas to produce a blended C1-containing substrate, and a conduit for passing the blended C1-containing substrate from the blending unit, to the fermentation unit.
17. The system of claim 15 wherein the energy source for the electrolysis unit is provided by a renewable energy production unit.