Activation of alumina-supported hydrotreating catalysts by organosulfides or H2S : Effect of the H2S partial pressure used during the activation process

The influence on the hydrodesulfurization (HDS) of dibenzothiophene (DBT) of different activation procedures using H2S or dimethyldisulfide (DMDS) has been investigated on phosphorus-free and phosphorus-doped CoMo and NiMo industrial catalysts supported on alumina. The comparison of the two sulfiding agents was performed using strictly similar procedures of sulfidation to determine the origin of the well-known beneficial effect of organosulfides for the activation of hydrotreating catalysts. Partial pressures in H2 and/or in sulfiding agents have been modified to observe activity variations among the different sulfiding agents used. Comparison between H2S and DMDS has also been performed on phosphorus-doped CoMoP/Al2O3 and NiMoP/Al2O3 catalysts.