Optimum operating conditions in closed-system industrial acetifiers (batch operation): a study by computer simulation

Abstract

This work studies the optimum operating conditions in theoretical industrial acetifiers using computer simulation techniques. The fundamental part of the simulator is a global model for the growth of Acetobacter aceti in submerged culture compiled from the literature. The model is based on an expression which brings together a function for the specific rate of growth and another function for the specific rate of death, which reflects the combined influences of acetic acid, ethanol and oxygen. The kinetic parameters of the model are refitted by non-linear least-squares-type techniques, using data obtained from laboratory and industrial experimentation.

The optimum operating conditions have been calculated for two types of batch process: those with constant concentrations of dissolved oxygen and those with a constant rate of oxygen transfer to the fermentation medium. In both cases, the influence on the evolution of the process of different initial concentration levels of ethanol, acetic acid, biomass, dissolved oxygen and K_La has been studied.