Axial dispersion of liquid in fluidised bed with external recycling: two dynamic modelling approaches with a view to control

摘要

In this paper, hydrodynamic modelling of a fluidised bed reactor is studied through two different approaches (the input/output model and the distributed parameters model), as the aim of our work is complete study of anaerobic digestion in a fluidised bed reactor. After identification of parameters based on several experiments, the use of each model is discussed according to the stated objectives. Orthogonal collocation is used to reduce the partial derivative equations and the resulting model is validated for all our experiments. We show that the axial dispersion model appears to be the best choice in our case to design a control law for the process. The different steps we followed during this study, enable us to model recycling outside the reactor in a very simple and satisfactory way.