Preparation and characterization of hydrotreating catalysts -: I.: Effect of preparation methods on properties of MoNiP/Al2O3 catalyst

Three methods for preparing hydrotreating catalysts, such as dry-mixing (DM), dry-mixing followed by impregnation (DM-I) and co-impregnation WO, were compared. The experimental data indicated that the active metals Mo and Ni on the surface of MoNiP/Al2O3(DM) catalyst have high dispersion degree and worse dispersion state. For MoNiP/Al2O3(DM-I) catalyst, the active metals have both good dispersion state and high dispersion degree. Based on a newly developed support gamma -Al2O3, MoNiP/Al2O3(CI) catalyst was prepared and its properties are very similar to MoNiP/Al2O3 (DM-I) catalyst. Hence, the HDN activity of both MoNiP/Al2O3(CI) and MoNiP/Al2O3 (DM-I) is obviously higher than that of MoNiP/Al2O3(DM) catalyst. In addition, MoNiP/Al2O3(DM-I) catalyst has larger surface area and pore volume, being suitable for hydrotreating hydrocarbon fractions, such as VGO (vacuum gas oil) and AGO (atmospheric gas oil). While MoNiP/Al2O3(CI) catalyst has larger pore size, being suitable for hydrotreating hydrocarbon fractions with larger molecular size, such as petroleum wax, vaseline, etc. The results of evaluation tests showed that the optimal calcination temperature for MoNiP/Al2O3(CI) catalyst is 450 degreesC.