Lubricating oil hydrogenation production technology

The ideal components of base oil are branched alkanes (iso-alkanes) and monocyclic cycloalkanes with long alkyl side chains, while the non-ideal components are thick cyclic aromatic hydrocarbons and thick cyclic alkanes. Traditional solvent refining process is to selectively extract and remove polycyclic hydrocarbons and other heterocyclic compounds with low viscosity index (such as sulfur, nitrogen compounds, gum, etc.), so as to improve the viscosity index of the oil, so as to improve the color and antioxidant stability. This physical separation method can only retain the original ideal components of the raw material. The improvement of base oil yield, viscosity index and other properties was limited. The hydrotreatment of lubricating oil is through deep hydrogenation conversion method, so that polycyclic hydrocarbons become ideal components, and almost completely remove heterocyclic compounds, so the base oil yield is high, and the improvement of oil quality indexes is more obvious.
In the hydrogenation process, the main chemical reactions are: (1) removal of heterocyclic compounds; Aromatic saturation, ring opening and isomerization of cycloalkanes are the most important reactions to improve the viscosity index; (3) Normal alkanes or low branching isomeric alkanes are isomerized to high branching isomeric alkanes by hydrogen; ④ Hydrocracking of alkanes and hydrodealkylation of alkanes with long alkyl side chains. This kind of reaction will lead to the production of light oil and reduce the yield of base oil. The first three are favorable responses, and the fourth is the response that needs to be suppressed.