Methods and systems for the production of alcohols and/or acids
Methods and systems for the production of one or more products from a gas stream produced in a methanol production process. The method comprises converting at least a portion of a methane feedstock to a substrate comprising CO and H2. The substrate comprising CO and H2 is anaerobically fermented in a bioreactor to produce one or more alcohols. The method and system may further include process for the production of methanol processes for the production of acetic acid.
1. A method comprising:
a. converting a gas stream comprising methane to a substrate stream comprising CO and H 2 ;
b. passing a portion of the substrate stream to a methanol synthesis process to convert at least a portion of the CO and H 2 in the substrate stream to methanol;
c. passing a portion of an exit stream comprising methanol and CO from the methanol synthesis process to a methanol carbonylation process to convert the methanol and CO to acetic acid;
d. passing an exit gas stream comprising CO and H 2 from the methanol synthesis process to a first bioreactor containing a culture of at least one carboxydotrophic bacteria and anaerobically fermenting at least a portion of the exit gas stream comprising CO and H 2 from the methanol synthesis process to produce at least one product selected from alcohols, acids 2,3-butanediol and combinations thereof;
e. passing an exit stream from the carbonylation process comprising acetic acid, by-products and waste products, to a separation vessel operated at conditions to produce an acetic acid product stream and a gaseous stream comprising CO;
f. passing the gaseous stream comprising CO from step (e) to the first bioreactor;
g. passing a portion of the substrate stream comprising CO and H 2 from step (a) to the first bioreactor;
h. passing an exit gas stream from the first bioreactor comprising H 2 and CO 2 , the exit gas stream being rich in H 2 , to a second bioreactor comprising a culture of at least one carboxydotrophic bacteria and anaerobically fermenting at least a portion of the H 2 and CO 2 to acetic acid.
2. The method of claim 1 , wherein the methane is converted to CO and H 2 by catalytic oxidation.
3. The method of claim 1 , wherein the at least one product produced in step (d) is selected from ethanol, 2,3-butanediol, acetic acid and any combination thereof.
4. The method of claim 1 , further comprising passing a CO 2 comprising stream to the second bioreactor.
5. The method of claim 1 , wherein the carboxydotrophic bacteria of step (d) is selected from Clostridium, Moorella, Carboxydothermus , and any combination thereof.
6. The method of claim 5 , wherein the carboxydotrophic bacteria is Clostridium.
7. The method of claim 6 , wherein the carboxydotrophic bacteria is Clostridium autoethanogenum.
8. The method of claim 1 , further comprising passing the H 2 rich exit gas stream from the first bioreactor to a recovery zone where at least a portion of the H 2 is recovered before passing the exit gas stream to the second bioreactor.
9. The method of claim 1 , wherein the at least one carboxydotrophic bacteria of step (h) is selected from Acetobacterium, Moorella, Clostridium, Ruminococcus, Eubacterium , Butyribacterium, Oxobacter, Methanosarcina, Desulfotomaculum , and any combination thereof.
10. The method of claim 9 , wherein the carboxydotrophic bacteria is Acetobacterium.
11. The method of claim 10 , wherein carboxydotrophic bacteria is Acetobacterium woodii.
12. The method of claim 1 , wherein the acetic acid produced by the carbonylation process is recovered.