Analysis of a continuous, aerobic, fixed‐film bioreactor. I. Steady‐state behavior

Abstract

The analysis of a continuous, aerobic, fixed‐film bioreactor is performed by simulating the behavior of penicillin production in a three‐phase fluidized bed. Rigorous mathematical models are developed for a fluidized‐bed fermentor in which bioparticles are fluidized by the liquid medium and air. The steady‐state performance of the fluidized‐bed reactor is appraised in terms of penicillin productivity and outlet concentration by considering the two extremes in contacting patterns, complete back‐mix and plug flow, in the absence of a growing biofilm. The results show that the complete back‐mix contacting pattern is preferred over that of plug flow due to the nature of the penicillin kinetic relationships. It is also shown that for the dual‐nutrient (glucose and oxygen) penicillin reaction system the optimum biofilm thickness does not equal the penetration depth of a limiting nutrient, but depends upon the total reactor configuration.