ANALYSIS OF SUBSTRATE CONVERSION IN A BUBBLE-COLUMN BIOREACTOR WITH AMEMBRANE-FILTER FOR CONTINUOUS-CULTURE

The steady-state performance, mainly with respect to substrate convers ion, of a bubble column bioreactor with substrate limited microbial gr owth and cell recycle through a membrane filter is investigated numeri cally. The dispersion model and the Monod equation are employed for de scribing flow behaviour and cell growth rate in the reactor, respectiv ely. Moderate longitudinal mixing causes a favourable effect on the su bstrate conversion. Such an effect is enhanced with increasing recycle ratio and separator concentration efficiency. There exists an optimum Peclet number to maximize the substrate conversion. The relation betw een the critical recycle ratio at which the optimum Peclet number beco mes zero and the corresponding exit substrate concentration is present ed.