METHOD FOR OBTAINING HIGH-VISCOSITY INDEX BASE OILS Russian patent published in 2023 - IPC C10G67/04 C10G7/06 

FIELD: oil refining.

SUBSTANCE: invention relates to oil refining processes, in particular to methods for obtaining high-viscosity index base oils of the first and second groups. The invention concerns a method for obtaining high-viscosity index base oils, which consists in selective solvent purification of oil distillates obtained by vacuum distillation of fuel oil and deasphalted tar oil from resins and asphaltenes, followed by solvent dewaxing and hydro-refining processes in the presence of a catalyst. Before vacuum distillation of fuel oil, an unconverted hydrocracking residue is added to it in an amount of 3.0-10.0 wt.%, the dewaxing process is carried out before the hydro-refining process, and hydro-refining is carried out at a ratio of hydrogen-containing gas: raw materials 300-349 nm³/m³.

EFFECT: increase in the viscosity index and the total yield of base oils; a decrease in sulfur content and the NOACK evaporation rate, improving the environmental friendliness of the production of oils and the final product.

1 cl, 1 dwg, 2 tbl, 1 ex