ONLINE ESTIMATION OF BIOMASS CONCENTRATION AND NON STATIONARY PARAMETERS FOR AEROBIC BIOPROCESSES

The biomass concentration, a very important state variable of almost e very bioprocess, cannot often be measured directly or estimated from r elated variables, such as the concentrations of substrates or products , due to the lack of reliable and cheap sensors. In this paper, a stab le observer of biomass concentration is designed for those aerobic pro cesses where the measurement of oxygen uptake rate is available on-lin e. This particular approach can also be applied for other reaction rat es if the model of the process satisfies some very general assumptions , which make the dynamics of the biomass growth rate and the biomass c oncentration a linear function only of this unknown parameter and this state variable. With respect to a previous similar approach, the new observer has a different linear structure, which allows a simple tunin g procedure. A comparison between the two different algorithms under s imilar conditions is realized.