Reactivity approach applied to hydrotreating processes: hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodeoxygenation (HDO).

Two methods can be considered when looking for new catalysts. On the one hand, a classical way, through experimental screenings of new materials according to standard operating conditions. Usually, selectivity, yield or compound distributions versus conversion are represented. Such data are closely related to the industry demand. One can try to look through a better understanding of the chemical reaction to optimize or develop new catalysts. Indeed, it can be worthy to have a substantial knowledge of the applied reaction to predict which active sites are needed. A global (or experimental) kinetic study i.e., studying the distribution of the products versus contact time is a useful tool. Such representation of data can give an instantaneous picture of the course of the reaction at the surface of the catalyst. Conversion, yield and selectivity can easily or directly be deduced from such a plot. Furthermore, these plots help to define the complex reaction pathways as a sum of successive, twins or concurrent elementary steps. It will be pointed out that the global kinetic study of hydrotreating reactions such as HDS, HDN or HDO reactions, leads to simple interpretations which fit the kinetic laws obtained at a mol. level.