Abstract: Using Feedstock A with high nickel(Ni) content and low vanadium(V) content (Ni and V mass fractions of 36.6 μg/g and 19.2 μg/g, respectively) and Feedstock B with low Ni content and high V content (Ni and V mass fractions of 23.8 μg/g and 83.0 μg/g, respectively), fixed bed residue hydrotreating experiments were carried out on the same fixed bed hydrotreating pilot-test unit with the same catalyst gradation under the conditions of a liquid-hour volume space velocity of 0.23 h^-1, a hydrogen partial pressure at the reactor inlet of 15.0 MPa, a hydrogen oil volume ratio of 700, and an average reaction temperature of 375.5 ℃. The results demonstrated that Feedstock B achieved superior hydrodemetallization performance. Compared with Feedstock A, Feedstock B showed higher Ni,V and (Ni+V) removal efficiency by 4.00,8.71 and 9.41 percentage points,respectively. This trend was corroborated in industrial operations when comparing Unit U1 processing high Ni content and low V content residue with Unit U2 processing low Ni content and high V content residue. U2 exhibited higher Ni removal by 4.52 percentage points, higher V removal by 8.18 percentage points, and higher total metal removal by 9.52 percentage points than U1,respectively. To enhance hydrodemetallization efficiency in fixed-bed residue hydrotreating, two strategic approaches are recommended: Laboratory development of catalysts and grading systems with enhanced conversion capability for resins and asphaltenes, followed by industrial implementation; Operational optimization through preferential processing or appropriate blending of feedstocks with lower Ni/V mass ratio or higher aromaticity in commercial units.

Key words: residue hydrotreating, feedstock, hydrodenickelization, hydrodevanadization, hydrodemetallization