Hydrothermal treatment of natural rectorite enhanced Mo sulfidation for slurry-phase hydrocracking of vacuum residue

Abstract

Natural rectorite modified by the hydrothermal method was employed to prepare a catalyst for the slurry-phase hydrocracking of vacuum residue (VR). The influence of hydrothermal treatment on the properties of rectorite and the performance of the corresponding catalyst was examined. Hydrothermal treatment of the rectorite led to the formation of Fe₃O₄, as evidenced by H₂-TPR analysis. XPS results indicate that the hydrothermal treatment of rectorite can intensify the sulfidation process of Mo species supported on it, possibly due to modifications in the surface properties of the rectorite. Comparative slurry-phase hydrocracking tests showed that the catalyst supported on hydrothermally treated rectorite exhibited significantly higher VR conversion, higher liquid product yield, and higher yields of gasoline and diesel fractions, but lower gas yield compared to the catalyst supported on untreated rectorite. This is ascribed to the high hydrogenation activity of the catalyst supported on hydrothermally treated rectorite, which effectively suppresses the over-cracking reactions of intermediate products that would otherwise produce gas, illustrating the process intensification achieved through hydrothermal treatment.