ANALYSIS OF A 2-STAGE FERMENTER WITH RECYCLE FOR CONTINUOUS ETHANOL-PRODUCTION

The performance of a recycle two-stage fermenter with cell separators after each stage is analyzed numerically for the continuous production of ethanol. rn this system, the bleed withdrawn from the first stage is introduced to the second tank in order to reuse the cells in the bl eed. Kinetic expressions and parametric values are taken from the lite rature. The effects of operating parameters on the concentrations in t he stages are examined. Also investigated are the critical dilution ra te for washout, the ethanol productivity and the substrate conversion. In addition, the influences of the saturation constant and the equili brium partition coefficient of ethanol are examined. With respect to t he overall productivity and conversion, it is found that the present t wo-stage system is more efficient than either a recycle chemostat or a recycle two-stage fermenter with a single separator after the final s tage.