Incorporating Unsteady State Models in Biorefinery Simulations: Optimization of Integrated Aspen Plus Unsteady State Fermentation and in Situ Gas Stripping Simulations

Aspen Plus stoichiometric steady state simulations may be inadequate for time-dependent processes of batch fermentations coupled to other unit operations, such as separation processes. The complex fermentation process streams interactions result in many tradeoffs among process parameters and slight changes in product yields/outcomes could significantly affect the process profitability. Linear optimization approaches that employ linearized models for the inherently non-linear process may be inadequate.

To this end, a multi-objective optimization strategy based on unsteady state models is used to optimize the operating conditions of integrated fermentation and in situ gas stripping processes to maximize the process parameters. This links the fermentation kinetics with fermentation environment and separations unit operations to provide strategies for process design, control and optimization of fermentation (biorefinery) processes. This research can serve as a basis to evaluate the economic viability and technical feasibility of biorefineries as a decision-support tool for researchers, investors and policy makers.