A neural-network based model of the kinetics in a fermentation process
is presented. In the development and application of the model, the st
ate of the process was estimated by an independent model based on elem
ental balances and an electroneutrality condition. The aim of the work
was a model that describes the overall kinetic relations well enough
to be used for on-line simulation and prediction. Both feed-forward an
d partially recurrent networks were investigated. The networks were tr
ained off-line, but in the on-line application they are adapted to the
process conditions by adjusting a set of correction factors. The appr
oach is illustrated on a number of batch runs of Saccharomyces cerevis
iae, where the networks are demonstrated to be able to accurately desc
ribe the biphasic growth.