TRANSIENT BEHAVIOUR OF CATALYTIC REACTIONS WITH STOP-EFFECT

Abstract

The transient behaviour of a heterogeneous catalytic process described by a two-site adsorption-desorption model was studied. After a stop on the supply of reactant, a temporarily increase in the production rate is predicted. Analytical solutions to describe the instantaneous reaction rate in a differential reactor are presented. The theoretical results explain published experimental observations, that the reaction rate under transient conditions can be several times higher compared to steady state. By model simulations it was found that the transient rate can be considerably higher than under optimal steady state conditions.

The relationships developed may be helpful in model discrimination and parameter estimation.

KEYWORDS:

• Stop-effect
• Transient behaviour
• Absorption/desorption models
• Heterogeneous catalysis