Approximation of the dynamical model of fixed bed reactors via a singular perturbation approach

In this paper, we propose to study the dynamics of fixed bed reactors with axial dispersion in the general case of a non-isothermal process involving N components and M reactions. It will be shown by using singular perturbation that for large dispersion coefficient values, the fixed bed reactor tends to a stirred tank reactor. Singular perturbation results in a series expansion of the state variables (component concentrations and temperature). The computation will be carried out up to the first order. The dynamical equations of the zero order approximation are the those of the corresponding stirred tank reactor