Optimization of microbioreactor operating volume by using attainable region approach

Abstract

This paper presents the development of a model-based methodology in identifying a suitable (i.e. appropriate) operating volume for a microbioreactor system. Optimization of the microbioreactor operating volume is formulated as a generic optimization problem and solved by decomposing it into five hierarchical stages: (i) pre-analysis, (ii) design target selection, (iii) process design analysis, (iv) final selection and fabrication, and (v) result validation. In the first stage, the concept of attainable region is used to locate the optimal process design solution in terms of optimal condition of operation, and economic point of view. The target for this optimal solution is defined and selected at the maximum point of the attainable region diagram. Accordingly the solution target at the maximum point of the attainable region shows the highest value of the objective function, hence the optimal solution for determine the optimum operating volume of the microbioreactor system. Finally, the size and dimension of the microbioreactor vessel is determined at the optimum condition and then the microbioreactor is fabricated on this basis. The validity of this model-based methodology is confirmed by performing series of fermentation experiments (i.e. conversion of glucose to lactic acid) in a microbioreactor setup that is fabricated according to the operating volume suggested. The results obtained confirm the suitability of the method for determine the operating volume of microbioreactor before fabrication phase.