DEVELOPMENT OF A PREDICTIVE DESCRIPTION OF AN IMMOBILIZED-CELL, 3-PHASE, FLUIDIZED-BED BIOREACTOR

A fully predictive mathematical description of a three-phase, tapered, fluidized-bed bioreactor is developed. This mathematical model includ es the effects of the tapered bed, variable dispersion coefficient, an d variable solid holdup upon the concentration profiles developed in t he bed. In addition, the effect of the concentration profile which is developed inside the biocatalyst bead is included by means of an effec tiveness factor calculation. Using accepted correlations for the dispe rsion coefficient and for the liquid, gas, and solid holdup in the bed , the model is fully predictive. The model was found to adequately pre dict experimental obtained concentration profiles. Then, the model was used to examine the various phase holdups through the bed and the deg ree to which the dispersion coefficient varied through the bed. The ef fect of changes in these calculated variables upon the reaction rate i s discussed. (C) 1995 John Wiley and Sons, Inc.