Evaluation of the Dynamic and Control Strategies of the Vapor Recovery Section of a FCC for a Plantwide Control Design

Abstract

The goal of plantwide control studies is to design a control system that can achieve the operating requirements of the complete plant optimal conditions. The problem focuses on the whole plant and not only on single equipment. The size of plantwide control problems are larger than that for individual units, making the solution much more difficult. The main problem is the presence of recycle streams that provide interactions between different equipment. Disturbances that enter a process can propagate not only downstream from one unit operation to the next but upstream through material and energy recycle loops. In this work, the product recovery section of a fluid catalytic unit was used to discuss the optimization and the control of large plants. This unit was chosen because of the presence of four material recycle loops, which allow the observation of equipment coupling. The control system must be able to reject not only local disturbances at the unit level but also at the plant level.