Abstract: Based on the process and parameters of the hydroisomerization/hydrofining in industrial production of API Ⅱ base oil and catalysts suitable for the processing of Fischer-Tropsch synthetic wax, the influence of Fischer-Tropsch synthetic wax as raw material and process parameters on the cloud point and pour point of API Ⅲ 5cSt base oil were studied in the 200 mL hydrogenation pilot plant. The results showed that high hydroisomerization temperature, low hydroisomerization pressure and low carbon number of Fischer-Tropsch synthetic wax could reduce the cloud point and pour point of 5cSt base oil. When Fischer-Tropsch synthetic wax was used as raw material, the proportion of hydrocarbons with carbon number more than 40 did not exceed 0.5%, the isomerization pressure was 2.5 MPa, and the temperature was 348 ℃, the cloud point and pour point of 5cSt base oil were not higher than -15 ℃ and -30 ℃ respectively, the viscosity index was not lower than 135, and the yield was not lower than 30%.

Key words: Fischer-Tropsch wax, hydroisomerization, lube base oil, low temperature property