Abstract: In order to increase the production of high quality continuous reforming feedstock, the No.1 4.0 Mt/a hydrocracking unit of Zhejiang Petrochemical Co., Ltd. was revamped and the original catalyst was replaced with chemical type hydrocracking catalyst RHC-220. After changing agent, the radial temperature difference at the bottom of each bed was controlled within 3 ℃, the yield of heavy naphtha increased from 29.29% to 42.73%, and the BMCI of unconverted oil decreased from 15 to 5.5. It can adapt to the working condition of the hydrogenated gas oil in slurry bed, enrich the raw material composition of the unit, ensure the high load operation of the unit, and optimize the product structure and quality of the unit. It provides strong support for the increasing production of PX with high added value.

Key words: heavy naphtha, inferior materials, hydrocracking, catalyst