Conclusions for Controllability

Steady-state and dynamic comparisons have been presented of an extractive distillation process using three different solvents. The numerical example examines the acetone-methanol separation using water, DMSO, or chlorobenzene solvents. 

The DMSO solvent gives the best steady-state economics and the best dynamic controllability. This is one of those uncommon situations in which there is no trade-off between controllability and steady-state economics. 

In this chapter, the use of extractive distillation has been illustrated using the acetone-methanol system as a numerical example. Steady-state and dynamic comparisons have been presented between extractive distillation and a pressure-swing distillation, with and without heat integration. In addition, the effect of solvent selection on dynamic controllability has been investigated. 

Knapp J. P. and M. F. Doherty, Thermal integration of homogeneous azeotropic distiUation sequences, AIChE J., 36, 969 984 (1990). 

Kossack S., K. Kraemer, R. Gani, and W. Marquardt, A systematic synthesis framework for extractive distillation processes, Chem. Eng. Res. Des., 86, 781-792 (2008). 

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