(636g) Dynamic Modeling of a Continuous Acetone-Butanol-Ethanol (ABE) Fermentation Process

Authors: 
Buehler, E., University of California-Berkeley
Mesbah, A., University of California - Berkeley
Continuous acetone-butanol-ethanol (ABE) fermentation has drawn interest for large-scale production of biobutanol due to biobutanolâ??s superior fuel properties over bio-ethanol and biodiesel [1]. Compared to batch fermentation, continuous ABE fermentation enables better control over process parameters and the possibility of achieving higher biobutanol productivity owing to the continuous product removal [1,2]. Dynamic modeling and analysis of integrated ABE fermentation and separation processes offer opportunities for optimal process design and operation. Dynamic models have been reported for fermentation processes integrated with product recovery units such as hollow fiber membrane, liquid-liquid extraction, and pervaporation [3]. In this work, we present a dynamic model for an integrated continuous ABE fermentation process that consists of a continuous fermentation unit [4], a tangential filtration unit, a membrane vapor extraction (MVE) unit [5], and a recycle stream. MVE is a novel product recovery technique that separates the vaporized solvent products from fermentation via solvent transport through a microporous, omniphobic membrane followed by isothermal absorption into a nonvolatile solvent [5]. The MVE unit enables continuous product removal with minimal energy consumption. An extensive dynamic sensitivity analysis has been performed to systematically investigate the effects of various kinetic and process parameters on the butanol productivity. The analysis provides guidelines for future process integration and optimization.

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