Catalyst Deactivation

The decrease in hydroprocessing response speed over time on stream is a sign of deactivation. In actual refineries, rising temperature counteracts a drop in activity. The characteristics of the feeds, the operating environment, and the structure of the catalysts all have a role in how much deactivation occurs. It is reasonable to expect a considerable difference between the deactivation of the catalyst during the hydroprocessing of heavy feeds and light feeds. In the case of atmospheric distillates, poisoning from N-compounds and coke deposition predominates in the catalyst deactivation process. Because they preferentially bind to active sites, the N-bases, which are found in all petroleum feeds, contribute to the catalyst's deactivation and slow down the hydrogen activation process.