Open Loop Optimal Operation and Sensitivity Analysis of a Continuous Biobutanol Fermentation Process with Ex-Situ Adsorption Recovery

Abstract

Biobutanol is considered to be an attractive biofuel due to its chemical similarity to gasoline, but low fermentation performance caused by butanol toxicity stands as a major obstacle in taking it to full commercialization. As a solution, an ex-situ recovery system with periodically switched adsorption column can be used to maintain the butanol concentration in a fermenter below the critical level. Due to the complex nature of the operation manifested by the periodic operation and the resulting cyclic steady state (CSS), it becomes a challenge to determine the optimal operation strategy of the system. In this study, an optimization problem is formulated to determine the operating condition to maximize a profit function at the CSS for a given feed concentration. This is followed by an open-loop sensitivity analysis to investigate the effect of uncertainties in the model parameters and adsorbent states on performance of the determined recipe.