A New Systematic Approach to Fi nd Plantwide Control Structures

Abstract A new systematic approach for addressing the problem of the plant-wide control structure, supported by steady-state information is presented. It is tested in a reactor/separator with recycle plant. Several authors have presented different control alternatives for this kind of plant. However, most of them mainly focused on the optimum energy consumption or in the regulator problem only. In both cases the decision of the final control structure was adopted based on several heuristic concepts. In this work both objectives are considered avoiding any heuristic concepts. The approach consists meanly on three steps: optimization, stabilization, and final pairing between manipulated and controlled variables focused on rejecting the most critical disturbances. In addition, the reactor design is subject to ensure quality product specification, cost investment together with the overall plant controllability. Finally, the dynamic model of the plant is used for testing the potentiality of the proposed control structure. Hence, a multivariable tuning procedure, based on internal model control (IMC), is performed for evaluating the dynamic closed loop responses under the worst disturbances scenarios.