Model building in complex catalytic reaction systems

Abstract

Catalytic rate-modelling forms an integral part of Process Development and Design as well as providing insight into the underlying reaction mechanisms. Industrial reactions are usually complex, involving several simultaneous and consecutive reactions, leading to a variety of products. In petro-chemical applications, in particular, the reactions often occur in the presence of continuous deactivation of the catalyst—a complex process which must also be modelled if an optimum plant design and operating policy are to be realized. This paper describes an approach to model building of such systems which requires a multi-step strategy of experimentation and analysis, using different types of laboratory reactor. The approach is applied to the kinetic modelling of simultaneous isomerisation and disproportionation of a mixture of xylenes over a silica-alumina catalyst which is subject to continuous coking.