Abstract (EN):
Residence time distributions have been largely used in chemical engineering to make diagnosis of the ill-functioning of chemical reactors and to predict conversion in homogeneous isothermal reactors once the kinetic rate of reaction is known. The prediction is unambiguous for first-order reactions. In this paper, the impulse tracer response of isothermal heterogeneous fixed-bed reactors packed with large-pore catalysts, in which intraparticle convection occurs, is derived. From the impulse tracer response, the residence time distribution of the outer phase is calculated and used to predict the steady state conversion in the reactor for first-order reactions. The effect of intraparticle convection, measured by the intraparticle Peclet number lambda for a given reaction-catalyst system, i.e. for a set of Damkholer, Thiele, Biot and Peclet numbers (Da, phi, Bi-m and Pe respectively) is to drive the conversion between the diffusion-controlled and the kinetic-controlled limits. The problem of scaling from batch to continuous packed beds is also addressed.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
10