Contrôle de la sélectivité des réactions d'hydrodésulfuration et d'hydrogénation en hydrotraitement (étude cinétique sur des essences craquées modèles)

In the oil context of a future market of gasoline without sulphur, this work deals with the selec-tive hydrodesulphurization of FCC gasoline on a CoMo/Al2O3 catalyst, the aim of this process beeing to remove the maximum of sulphur compounds while minimizing the olefins hydro-genation. For a better understanding of the mechanisms involved in this process and to try to clarify the number of different active sites on the catalyst, an experimental approach with model compounds has been chosen to study the kinetics of the HDS, HYD, isomerisation and recombination reactions. This work allowed us to evidence the existence of a thermodynamic equilibrium between olefins and thiols, and adsorption of olefins and sulphur compounds has been demonstrated to occur on the same active sites. Moreover, our results indicate that the hydrogen sulphide governs the selectivity HDS/HYD, whatever was the addition of secondary compounds (nitrogen compounds, xylenes, hydrogen ). A kinetic model based on the exis-tence of a single type of active sites allowed to explain most of the results obtained during this workLYON1-BU.Sciences (692662101) / SudocSudocFranceF