TABLE OF CONTENTS Mathematical models have been developed and used for predicting long-time performance of the catalysts during hydroprocessing of petroleum feeds. In this regard, rather extensive information can be found in the scientific literature. In the following, a summary of these efforts is only given, although the wealth of information suggests that a separate book can be written on this subject.
The first stage of model development involves derivation of the mathematical expressions which may predict the performance of catalyst. Subsequently, the validity of these equations is verified using the experimental data. After modifications, these models can be used to generate the database for selecting catalysts to match the feed of interest with a suitable reactor as well as to predict a long-term performance of the system. The database necessary for the design of catalysts and reactors to suit a particular feed can be readily generated using the models as well.
Models incorporate changes in the interphase, intraphase and interparticulate gradients of temperature and concentration with TOS. The complexity of chemical structure of heavy feeds compared with light feeds suggests that the development of models to simulate hydroprocessing of the former is much more challenging than that for light feeds. It requires the determination of performance parameters such as the change in catalyst activity for hydroprocessing reactions with TOS, the parameters accounting for catalyst deactivation, metal storage capacity of catalyst, pore size distribution, etc. The experimental techniques for determining most of the required parameters...
