Toward a Flexible Design for the Bioethanol Dehydration Using Extractive Distillation. Part 1: Steady-State Design and Optimization

This study introduces a novel approach to the initial design of bioethanol dehydration, incorporating process fluctuations. Unlike previous studies, which overlooked fluctuations, we aim to determine the feasible operating range of the process by considering them. Initially, the bioethanol dehydration base case was optimized individually for cost and flexibility, resulting in the most economical and flexible process. However, a trade-off between these objectives was observed, leading to the optimization of an integrated function (TACFI) that balances the total annual cost (TAC) and flexibility index (FI). The optimized design can tolerate a 21.3% decrease in the feed flowrate and a 21.3% increase in ethanol concentration, exceeding typical fluctuation ranges observed in dynamic performance testing. This highlights the significant controllability potential of the design, emphasizes the importance of considering operational flexibility during the early phase of process design, and offers valuable insights for industrial applications of extractive distillation for bioethanol dehydration.