PERFORMANCE EVALUATION OF IDEAL HEAT-INTEGRATED DISTILLATION-COLUMNS

In order to understand the operating feasibility of the ideal heat int egrated distillation column (HIDiC), its control systems are studied i n both time and frequency domains with respect to three operating cond itions (i.e., feed thermal condition, q<0.5, q=0.5 and q>0.5). It was found that the ideal HIDiC could be operated quite smoothly under all these operating conditions, However, the strongest interaction between top and bottom control Loops is observed at q=0.5, and the system res ilience may be degraded when q strays from 0.5 because of the strong g ain directionality of the profess. The feed location also strongly aff ects the dynamic performance of the ideal HIDiC. Placing feed in the m iddle of the process could intensify the interaction between the top a nd bottom control loops, Therefore, the determination of both feed the rmal condition and feed location should be based on a careful compromi se between steady state energy saving and dynamic resiliency of the sy stem.