Determining Appropriate Configuration of Ideal Heat Integrated Distillation Columns(HIDiC).

The major concern in developing various kinds of heat integrated distillation columns is the strong interaction and high sensitivity resulting from heat integration (Takamatsu, 1996), which could drastically deteriorate system potential performance. Hence, it is of great importance to design processes so as to make these undesired properties as small as possible, namely to increase system dynamic resilience. As for the ideal heat integrated distillation column (HIDiC), we already know that its symmetrical specifications, such as equal feed split, middle feed location and same structures between rectifying and stripping sections, are the main reasons for strong interaction between top and bottom control loops (Huang et al, 1996). In order to make the ideal HIDiC have higher dynamic resilience, these kinds of symmetrical specifications should be deleted. A previous work (Huang et al, 1996) already explored how to improve the system resilience through appropriately assigning feed thermal condition q and feed location under general configuration of the ideal HIDiC. As to the effects of symmetrical structure between rectifying and stripping sections, its effects are still not clear. In this work we will concentrate on this problem by studying three possible configurations of the ideal HIDiC. Both time and frequency domain techniques have been employed to assess the potential effects of system configuration towards system performances, and the results obtained are further evaluated through rigorous nonlinear closed-loop simulation.