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The objective of this work is the re-identification of the process model that is used in existing predictive controllers (MPC) using closed-loop operation data. The controller is assumed to have a two-layer structure, where in the upper layer a simple economic optimization algorithm determines a set of optimal steady-state values ​​("targets"), which are passed to the MPC for implementation. This is the case for several commercial MPC packages applied in the industry. This paper focuses on the case where the model represents significant benefits in the MPC re-commissioning procedure. A new methodology is proposed to excite the system in closed loop, introducing persistent excitation signals in the objective function of the upper layer of the MPC. This strategy allows the continuous operation of the system, respecting the constraints of the process and meeting the specifications of th...

The purpose of this paper is to optimiza the operation of an upflow anaerobic sludge blanket (UASB) reactor. In this kind of processes, besides to maximiza organic matter removal, it is attractive to capture the biogas and to use it to provide energy services. For this purpose, the biogas has to be produced in large quantities. Thus, we have two clear objectives to be achieved: to maximiza both the organic matter removal and the biogas production. Three multiobjective optimization techniques are used to solve this problem. The first optimization approach is multiplex, which is based on the simplex method for single objective optimization. Other used approach is an interior point method, which is proved to be an efficient linear programming technique. Finally, it is applied an evolutionary algorithm, namely the elitist non-dominated sorting genetic algorithm (NSGA 11), which is considerad...

The purpose of this paper is to optimiza the operation of an upflow anaerobic sludge blanket (UASB) reactor. In this kind of processes, besides to maximiza organic matter removal, it is attractive to capture the biogas and to use it to provide energy services. For this purpose, the biogas has to be produced in large quantities. Thus, we have two clear objectives to be achieved: to maximiza both the organic matter removal and the biogas production. Three multiobjective optimization techniques are used to solve this problem. The first optimization approach is multiplex, which is based on the simplex method for single objective optimization. Other used approach is an interior point method, which is proved to be an efficient linear programming technique. Finally, it is applied an evolutionary algorithm, namely the elitist non-dominated sorting genetic algorithm (NSGA 11), which is considerad...