Multi-Objective Optimization of an ABE Fermentation System for Butanol Production as Biofuel

Abstract

Abstract In this work, a previously reported unstructured kinetic model of Clostridium acetobutylicum ATCC 824, validated with experimental data under different culture conditions, was used to determine the optimal process conditions from an ABE fermentation system for biofuel production. The goal of this work was to simultaneously maximize two conflicting objectives: volumetric productivity and final concentration of butanol considering both Fed-Batch and single-stage CSTR operation regimes using either a free or immobilized cell reactor. The result of the after mentioned strategy was the construction of the Pareto Fronts and optimal trajectories for the inlet solution feeding rate and concentration using a Sequential Quadratic Programming methodology. The obtained results suggest that the maximum concentration and productivity of butanol are achieved in a semi-continuous system operating with immobilized cells, obtaining values of 19.1454 kg m-3 and 0.3655 kg m-3 h-1, respectively, representing an increase of 48 % and 104 % compared to the most recent industrial process reported to date.