Dynamic modelling of a gas phase catalytic fixed-bed reactor—II: Results from dynamic experiments

Abstract

The dynamic experiments on the fixed bed reactor consist of periodic changes in inlet conditions as well as start-up and step disturbances. The experimental results are compared with simulations using a simple one dimensional homogeneous model. The model parameters are determined in mutually independent groups. One group is the kinetic parameters which have been estimated in Ref.[1]. Another group is the heat transport parameters found from heat regenerator experiments. The experiments and the estimation method are described in this paper. The results show that the thermal residence time should be augmented 10% in order to account for the combined effect of radial velocity profile, nonadiabaticy and dynamic heat exchange with the reactor insulation. The estimated total heat transport Peclet number is high indicating that no dispersion phenomena apart from those characteristic for a packed bed are present. The agreement between simulations and experiments is fine for all types of experiments. The effect of radial velocity profile has been investigated separately. This involves solution of a model with two spatial dimensions. Through using a double collocation method combined with Runge-Kutta integration of the ordinary differential equations reasonable calculation times have been obtained.