ANALYSIS OF A 2-STAGE FERMENTER WITH CELL RECYCLING FOR CONTINUOUS ACETIC-ACID PRODUCTION

The steady-state performance of a recycle two-stage fermenter with cel l separators after each stage is studied numerically for continuous pr oduction of acetic acid. This system has two fresh-medium feed streams and the bleed withdrawn from the first stage is supplied to the secon d fermenter for utilization of the high cell concentration in the blee d. Kinetic expressions and parameter values are taken from the literat ure. The effects of operating parameters on the concentrations of cell s, substrate and product in the two stages, the critical dilution rate for washout, the acetic acid productivity and the substrate conversio n are examined and discussed. For overall productivity and conversion, the present two-stage system is found to be more efficient than a rec ycle chemostat and a recycle two-stage fermenter with a separator afte r the final stage. It exhibits sufficient promise for the continuous p roduction of acetic acid that it should be tried out experimentally.