Abstract: The 4.0 Mt/a hydrocracker of CNOOC Huizhou Petrochemical Company Limited was modified by using RN-410C/RHC-210/RHC-220 graded catalysts and fractionation system revamping to upgrade the production of high-quality chemical feedstocks. The calibration results show that using the VGO feedstock, blended with 20.16% of CGO, with the nitrogen mass fraction of 0.1846% and a density (20 ℃) of 0.910 g/cm³, under the conditions of an inlet pressure of 15.18 MPa, an average hydrotreating temperature of 385.6℃ and average hydrocracking temperature of 389.3℃, the hydrogen consumption is 2.98%, heavy naphtha yield is 35.23%, and tail oil yield is 10.69%. The naphtha, jet fuel, and diesel products can meet the specification requirements. The smoke point of jet fuel can reach 30 mm, the cetane index of diesel with 1% of polycyclic aromatics, can reach 72.3, and the BMCI value of tail oil is 12. The energy consumption of the unit is 21.91 kgEO/t(1 kgOE=41.8 MJ), reaching the advanced level of similar units. The selectivity of heavy naphtha increased from 77.3% in the previous cycle to 84.2% in this cycle, indicating a significant effect of catalyst gradation and reaction zone regulation.

Key words: naphthene-base, hydrocracking, heavy naphtha, jet fuel, tail oil