Encontrados 9 documentos, a visualizar página 1 de 1
A tool to analyze robust stability for constrained nonlinear MPC
Santos, Lino O.; Biegler, Lorenz T.; Castro, José A. A. M.A sufficient condition for robust asymptotic stability of nonlinear constrained model predictive control (MPC) is derived with respect to plant/model mismatch. This work is an extension of a previous study on the unconstrained nonlinear MPC problem, and is based on nonlinear programming sensitivity concepts. It addresses the discrete time state feedback problem with all states measured. A strategy to estimate b...
The unscented filter as an alternative to the EKF for nonlinear state estimatio...
Romanenko, Andrei; Castro, José A. A. M.The Kalman filter has been widely used for estimation and tracking of linear systems since its formulation in 1960 due to its simplicity and robustness. In many chemical engineering applications the extended Kalman filter (EKF) is often used to deal with certain classes of nonlinear systems. In spite of that, designing an EKF for highly nonlinear processes is not a trivial task, particularly those involving hig...
Nitrophenols Reduction in the Benzene Adiabatic Nitration Process
Quadros, Paulo A.; Castro, José A. A. M. Castro; Baptista, Cristina M. S. G.The benzene adiabatic nitration process has been carried out in a pilot plant to enable the study of this reaction under relevant industrial operating conditions, aiming to increase the reaction conversion and selectivity by reducing the nitrophenols. The influence of relevant operating parameters such as the reaction temperature, benzene-to-nitric acid molar feed ratio (FB/FN), and stirring speed was studied. ...
Modeling intra-particle convection in heterogeneous non-catalytic reacting systems
Fernandes, Natércia C. P.; Castro, José A. A. M.A dynamic mechanistic model of a multi-phase heterogeneous batch reactor processing a non-catalytic fluid-solid reaction is developed and numerically solved. The model takes into account both intra-particular convection and diffusion phenomena, as well as chemical reaction between the fluid and the solid. By addressing the until now ignored case of convection originated by the continuous increase of the particl...
On-line implementation of nonlinear MPC: an experimental case study
Santos, Lino O.; Afonso, Paulo A. F. N. A.; Castro, José A. A. M.; Oliveira, Nuno M. C.; Biegler, Lorenz T.A nonlinear model predictive control algorithm is implemented on-line to control the liquid level and temperature in a pilot plant CSTR, where an irreversible exothermic chemical reaction is simulated experimentally by steam injection. The dynamic behavior of the pilot plant reactor is represented using a mechanistic, first principle model and a comparison between off-line simulation and experimental data is pr...
Polymerization of beta-pinene with ethylaluminum dichloride (C2H5AlCl2)
Guiné, Raquel P. F.; Castro, José A. A. M.The main goal of this work is to study the cationic polymerization of terpenes, particularly of beta-pinene, with alkylaluminum catalysts. Some experiments at different polymerization temperatures (10, 20, and 50°C) were carried out with ethylaluminum dichloride catalyst, C2H5AlCl2. From the results, it is possible to draw some general conclusions about the evolution of chain growth during polymerization. This ...
Steady-state simulation of a continuous moving bed reactor in the pulp and pape...
Fernandes, Natércia C. P.; Castro, José A. A. M.This paper is concerned with the mathematical modeling and simulation of the steady-state operation of an industrial moving bed heterogeneous reactor for the kraft pulping of Eucalyptus globulus. The cooking takes place in a single-vessel hydraulic digester adapted for isothermal cooking (ITC), a further development of the modified continuous cooking (MCC) process. A heterogeneous model is used to take into acc...
An RT-Linux based control system of a pilot plant for reaction kinetics and pro...
Romanenko, Andrei; Castro, José A. A. M.The pilot plant under study is designed for determining the kinetics of the heterogeneous non-catalytic reaction of chemical pulping of wood and for teaching system dynamics and batch process control in an appropriate university course. The natura complexity of the system includes time varying dynamics and stepwise behavior and this makes it attractive for highlighting some important features of the real world ...
Improving safety of a pilot reactor using a model based fault detection and ide...
Afonso, Paulo A. F. N. A.; Tavares, João M.; Castro, José A. A. M.This work describes the experimental implementation of an automatic scheme for the on-line detection and identification (FDI) of faults in the sensors of an industrial scale pilot plant reactor under process control, where a pseudo zero-order exothermic chemical reaction is partially simulated. The main goals of this research are to enhance the safety of reactor operations and to demonstrate the potential of FD...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||