Analysis and control of heteroazeotropic batch distillation

✍ Scribed by S. Skouras; S. Skogestad; V. Kiva

• Publisher: American Institute of Chemical Engineers
• Year: 2005
• Tongue: English
• Weight: 192 KB
• Volume: 51
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.10376

✦ Synopsis

Abstract

The separation of close‐boiling and azeotropic mixtures by heterogeneous azeotropic distillation is addressed in batch columns. Both a common rectifier and a multivessel batch column are considered. Theoretical and graphical analyses of the process are presented for both column configurations and different separation strategies are presented. A simple control scheme is proposed for the practical operation of the columns, the implementation of different separation strategies and the realization of the final results. Dynamic simulations for mixtures classified under Serafimov's topological classes 2.0‐2b and 3.1‐2 verify the theoretical findings. The results show that heteroazeotropic batch distillation exhibits substantial flexibility. The column profile can be totally restored during the process and lie in regions different from those of the initial feed. The still path can cross distillation boundaries and the still product does not have to be the stable node of the feed region. Such results cannot be obtained by homogeneous azeotropic batch distillation. © 2005 American Institute of Chemical Engineers AIChE J, 2005