Head Pressure minimization of a Visbreaking column through an advanced PID controllers architecture

In this paper an advanced PID control architecture developed to minimize the head pressure of a visbreaking column is presented. The implemented control strategy has been designed through an advanced interconnection of PID controllers typically used in industrial processes: cascade control, feedforward control and override control. In order to correctly identify the interactions of the key variables, a RGA analysis has been performed. The proposed control system has been previously tested on simulation, thus been able to evaluate its performances in terms of robustness, stability and rejection of the main disturbances of the process. The results on the plant of the column optimization confirmed its effectiveness in the minimization of the head pressure. In this way, the new controller guaranties an increase of the separation between the heavy and light components and an increase of the extraction of the valuable products like gasoline and Light GasOil. The application of the proposed control architecture has allowed reaching an important economic recovery.