FERMENTATION AND SIMULATED MOVING BED PROCESS
The invention provides an improved method for the production, separation and recovery of one or more fermentation products from a fermentation broth. Further, the invention provides a method for increasing efficiency of a fermentation reaction. In particular, the invention relates to a fermentation system which incorporates a simulated moving bed for separation of fermentation products from a fermentation broth, and a corresponding method
1 . A method for producing and separating at least one fermentation product from a mixture of fermentation products in a fermentation broth, the method comprising:
a) fermenting a gaseous substrate in a bioreactor containing a culture of at least one microorganisms to produce a fermentation broth comprising a mixture of fermentation products where the mixture comprises at least two products selected from the group consisting of ethanol, acetic acid, 2,3-butanediol, butanol, iso-propanol and acetone;
b) passing the fermentation broth to a treatment zone operated at conditions to remove substantially all suspended and soluble biomass and produce a treated broth stream;
c) passing at least a portion of the treated broth stream to a simulated moving bed (SMB) module comprising at least one adsorbent;
d) adsorbing at least one fermentation product onto said adsorbent and yielding a raffinate comprising the non-adsorbed components of the treated broth stream; and
e) desorbing the at least one product from the adsorbent to yield a product stream.
2 . The method of claim 1 , wherein the treatment zone comprises a heat treatment zone.
3 . The method of claim 2 , wherein the treatment zone further comprises a filtration zone.
4 . The method of claim 1 , wherein the mixture of fermentation products comprises ethanol, acetic acid, and 2,3-butanediol.
5 . The method of claim 1 , wherein the adsorbent is selected from the group consisting of fluorinated carbon, activated carbon and modified C18 silica gel.
6 . The method of claim 1 , wherein the desorbent is selected from the group consisting of ethanol, methanol, propanol and methyl tertiary butyl ether.
7 . The method of claim 1 , wherein the product stream contains water at a concentration of less than 5% by volume.
8 . The method of claim 1 , wherein the raffinate contains ethanol at a concentration of less than 5% by volume.
9 . The method of claim 1 , wherein at least a portion of the raffinate of step (d) is recycled to the bioreactor of step (a).
10 . The method of claim 1 , wherein the microorganism is selected from the genus consisting of Moorella, Clostridia, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, Desulfotomaculum , and mixtures thereof.