Abstract: In order to meet the market demand for low-pour point diesel and to improve the utilization ratio of the unit, the feasibility of increasing the production of low pour point diesel No. －35 by using the existing 0.15 Mt/a lub base oil hydrotreating unit was studied in PetroChina Karamay Petrochemical Co.,Ltd. The results of commercial production and calibration show that the freezing point of product diesel is decreased from －22 ℃ to －58 ℃, and the cold filter plugging point is decreased from －1 ℃ to －32 ℃, the cold flow properties of the product diesel are significantly improved. The economic accounting results show that the unit can produce 54 kt of low pour point diesel in the whole year, and the economic benefit is increased by 12.1 million Yuan/a.

Key words: hydrotreating, low pour point diesel, hydrodewaxing, lubricating oil