Production optimization with operating constraints for a fed-batch reactorwith DMC predictive control

This work presents a production optimization approach with operating constr aints applied to a fed-batch penicillin process with a DMC predictive contr oller. A deterministic and non-structured mathematical model of the fed-bat ch penicillin production process solved by a fourth order variable step Run ge-Kutta-Gill algorithm type simulated the system. The production process o ptimization has been performed through the manipulation of the initial cell and the substrate fed-batch concentrations besides the fed-batch flow rate strategy. In order to carry out this procedure it was necessary to compute a production index that considers product amount and process operating con straints such as cell, substrate and dissolved oxygen concentrations beside s the bioreactor final volume through the penalty functions concept. The op timization algorithm was based on the modified simplex method. The DMC cont rol algorithm was implemented in order to stabilize the dissolved oxygen co ncentration through the agitation speed manipulation. This controller was f ound to be appropriate to work coupled with a optimization procedure due to the fact that it gives a smooth behavior to this critical constraint even with all disturbs during the convergence. (C) 1999 Elsevier Science Ltd. Al l rights reserved.