PPT Slide
MODELING AND SIMULATION FOR CITRIC ACID FERMENTATION BY ROTATING DISK CONTACTOR
Akihiko Sakurai & Mikio Sakakibara
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Fukui University, Fukui 910, JAPAN
Department of Chemical Process Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060, JAPAN
A simple model was presented to describe the time courses of citric acid production by a rotating disc contactor (RDC) using Aspergillus niger. The model is expressed by Monod-type cell growth, Luedeking-Piret-type citric acid production rate equations, and the diffusion equation for oxygen in the biofilm. The model contains five parameters which were determined by the non-linear least squares method by fitting the numerical solution to the experimental data. In solving the equations, the cell density of the biofilm was estimated from the value of cellular mass per unit of biofilm area using an empirical equation, The experimental time courses in citric acid production period were well simulated with this model. The relation between the specific biofilm surface area and the rate of citric acid production was also explained by the simulation using the average values of five parameters of twelve runs.