Toward a Flexible Design for the Bioethanol Dehydration Using Extractive Distillation. Part 2: Validation of Operability under Uncertainty Using Base-Layer Control

Here, we validated the flexibility of the bioethanol dehydration process from our previous work (Tsai, C.-Y.; Ang, T.; Kong, Z. Y.; Sunarso, J.; Adi, V. S. K. Ind. Eng. Chem. Res. 2023, DOI: 10.1021/acs.iecr.3c01854.) via dynamic simulation. Previously, we integrated flexibility index (FI) into the initial design of extractive distillation (ED) to address variability and uncertainties in the early design stage, fostering robustness. However, a notable concern arose when incorporating FI into a steady-state environment, raising questions about the system's closed-loop dynamic behavior and resilience to disturbances. To tackle this, we transformed steady-state models into dynamic models using Aspen Plus Dynamics. Our validation revealed that the cost-minimization model aligns well with steady-state simulations, while the FI maximization and the integrated function (TAC_FI) models behave differently. Nonetheless, optimizing the model based on the FI indeed enhances flexibility, consistent with our prior work. Overall, integrating operational flexibility into steady-state design improves the operational flexibility of bioethanol dehydration via the ED process.