Fermentation and simulated moving bed process

Abstract

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

What is claimed is: 
     
         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.