Abstract: In order to flexibly adjust the ratio of diesel to gasoline and produce low pour point diesel while taking into account the high production of naphtha in winter, a new generation hydrofining catalyst PHD-112 and a hydrocracking catalyst PHU-301, developed by PetroChina Petrochemical Research Institute, were used to produce low pour point diesel in accordance with the standard of China Ⅵ in Refining and Chemical Complex of Yumen Oilfield，PetroChina. After stable operation of the unit for 3 months, calibration work was carried out. The results showed that after the mixture of FCC diesel, coker gasoline, and straight-run diesel was treated with graded PHD-112/PHU-301 catalysts, the sulfur content, nitrogen content and polycyclic aromatic hydrocarbon content of feed oil decreased from 4 260 μg/g to 3.6 μg/g, from 96 μg/g to 0.32 μg/g, and from 18.9% to 6.2% respectively, the hexadecane index increased by 1.6, the condensation point decreased to －28 ℃, and the cold filter point decreased to －20 ℃. At the same time, naphtha yield increased by about 10 percentage points (relative to feed amount), which showed that PHD-112/PHU-301 catalyst had good performance in desulfurization, denitrification, pour point depression and naphtha production. It could meet the production of low pour point diesel with China Ⅵ through diesel hydrotreating unit.

Key words: hydrofining, hydrocracking, low pour point diesel