Figure 1. Structure of the control system structure as the existing distillation column in the Danube Refinery was created. The model was adapted according to the data of the sensors and laboratory measurements. The controlled quality values were provided by inferential calculations based on archived data of the unit. During the analyses a control structure was created which could be suitable for the quality control of the column, and also the resulting models can be used in the implementation of Advanced Process Controllers (APC). *Correspondence: Iszaboszhb@mol.hu Table 1. Disturbances 2. Experimental Figure 3. Validation of the Simulator Figure 4. FC1 controller Table 2. Input parameters of inferential calculations Hungarian Journal of Industry and Chemistry Table 3. Relative Gain Array Figure 5. Performance of inferential calculations temperature and pressure measurements). One hour- long periods were aggregated from the online data before each laboratory sample time. From these values pressure compensated temperatures (PCT) and ratios of the mass flowrates were also calculated. Figure 6. Open loop test CV2 — MV2 Figure 7. APC models The following final control pairings were applied: CV1-— MV1, CV2 — MV3 and CV3 — MV2. According to this analysis quality control can be achieved using simple PID control loops. Therefore, the analysis of the closed-loop quality control in the following chapter was performed using only PID loops. This analysis was also the basis of an APC implementation. The initial APC models can be seen in Fig.7.
