Abstract: Compared with solvent refining process, the UV and thermal stability of naphthenic base oil from high pressure hydroprocessing is poor. UV and thermal stabilizers are generally added to solve this problem. Taizhou Petrochemical Company was also used the same method for N4006 and N4010 base oils, and the cost is increased by 80 yuan/t. Therefore, tests of increasing post-hydrofining temperature are conducted to improve the oil stability. The results showed that higher temperature of post-hydrofining can improve the UV and thermal stability of N4006 effectively, while no obvious effect on N4010. The yield of either base oil is not affected.

Key words: processing unit, naphthenic base oil, UV and thermal stability, temperature rise test