Method and system for producing products by fermentation

Abstract

A system is for producing products, advantageously solvents, by fermentation, advantageously multi-stage fermentation. The fermentation is complemented with pervaporation as in situ product recovery technology, combined with a multistage condensation of the permeate. The condensates are separately introduced in the downstream processing of the system to recover the produced products, advantageously solvents. The system for producing products, advantageously solvents, by fermentation is simplified and has an overall improved energy efficiency, compared to systems described in the art.

1 . A system for producing products by fermentation, the system comprising:
 a first fermenter;   a pervaporation unit communicating with a first outlet of the first fermenter;   a first condenser communicating with a permeate outlet of the pervaporation unit, and having a condensate outlet and a residue outlet;   a second condenser communicating with the residue outlet of the first condenser;   at least one pump arranged between the first condenser and the second condenser, wherein the at least one pump is configured to maintain the first condenser at a lower pressure than the second condenser;   a first distillation column communicating with a condensate outlet of the second condenser;   a decanter communicating with the condensate outlet of the first condenser and with a first outlet of the first distillation column.   
     
     
         2 . The system of  claim 1 , wherein the system is configured to control a first temperature of the first condenser and a second temperature of the second condenser, the first temperature and the second temperature being between 0° C. and 20° C. 
     
     
         3 . The system of  claim 1 , further comprising:
 a second fermenter communicating with a second outlet of the first fermenter;   a steam stripper communicating with an outlet of the second fermenter and communicating with an inlet of the first distillation column.   
     
     
         4 . The system of  claim 1 , wherein the first condenser is configured to operate at a first pressure below atmospheric pressure. 
     
     
         5 . The system of  claim 4 , wherein the first pressure is between 5 mbar and 200 mbar. 
     
     
         6 . The system of  claim 2 , wherein at least one of the first temperature and the second temperature is between 0° C. and 15° C. 
     
     
         7 . The system of  claim 2 , wherein at least one of the first temperature and the second temperature is between 0° C. and 10° C. 
     
     
         8 . The system of  claim 2 , wherein the first temperature and the second temperature are substantially identical. 
     
     
         9 . The system of  claim 2 , wherein the first condenser is configured to operate at a first pressure between 5 mbar and 200 mbar. 
     
     
         10 . The system of  claim 3 , further comprising a heat exchanger arranged between the outlet of the second fermenter and the steam stripper. 
     
     
         11 . The system of  claim 1 , wherein the at least one pump comprises a vacuum pump.