Optimal Design of Protein Production Plants with Time and Size Factor Process Models

JORGE M. MONTAGNA; ALDO R. VECCHIETTI; OSCAR A. IRIBARREN; JOSE M. PINTO; JUAN A. ASENJO

BIOTECHNOLOGY PROGRESS

AMER CHEMICAL SOC

Lugar: Washington; Año: 2000 vol. 16 p. 228 - 237

8756-7938

In this work we propose an optimization model for the design of a biotechnologicalmultiproduct batch plant. A first level of detail posynomial model is constructed foreach unit, as well as decisions regarding the structural optimization of the plant. Aparticular feature of this model is that it contains composite units in whichsemicontinuous items operate on the material contained by batch items. This occursin the purification steps, in particular with the microfilters operating between retentateand permeate vessels, and with the homogenizer and ultrafilters operating on thematerial contained in a batch holding vessel. Also, the unit models rely on batchoperating time expressions that depend on both the batch size and the size ofsemicontinuous items. The model takes into account all of the available options toincrease the efficiency of the batch plant design: unit duplication in-phase and outof-phase and intermediate storage tanks. The resulting mathematical model for theminimization of the plant capital cost is a mixed integer non-linear program (MINLP),which is solved to global optimality with an implementation of the outer approximation/equality relaxation/ augmented penalty (OA/ER/AP) method. A plant that producesfour recombinant proteins in eight processing stages is used to illustrate the proposedapproach.