Composition of lubricating oil

Lubricating oil is generally composed of two parts: base oil and additive. Base oil is the main component of lubricating oil, determines the basic properties of lubricating oil, additives can make up for and improve the lack of performance of base oil, give some new properties, is an important part of lubricating oil.
Base oil
Lubricating oil base oil is mainly divided into three categories: mineral base oil, synthetic base oil and biological base oil. The mineral base oil is widely used and the amount is large (about 95% or more), but some applications must use the products of synthetic base oil and biological oil base oil, so that these two base oils have been rapidly developed.
Mineral oil base oil is refined from crude oil. The main production processes of lubricating base oil are: atmospheric and vacuum distillation, solvent deasphalting, solvent refining, solvent dewaxing, clay or hydrogenation supplement refining. In 1995, China revised the current lubricant base oil standard, mainly modified the classification method, and added two special base oil standards for low coagulation and deep refining. In the production of mineral lubricants, the most important thing is to choose the best crude oil.
The chemical composition of mineral base oils consists of high boiling point, high molecular weight hydrocarbon and non-hydrocarbon mixtures. Its composition is generally alkanes (straight chain, branched chain, multi-branched chain), cycloalkanes (monocyclic, bicyclic, polycyclic), aromatic hydrocarbons (monocyclic aromatic, polycyclic aromatic), cycloalkyl aromatic hydrocarbons and organic compounds containing oxygen, nitrogen, sulfur and other non-hydrocarbon compounds such as gum and asphaltene. Bio-based oils (vegetable oils) are becoming more and more popular because they can biodegrade and rapidly reduce environmental pollution. The synthetic lubricating oil has the characteristics of excellent low temperature performance, good lubrication performance and long service life, and can be applied to the environment of high load, high speed, high vacuum, high energy radiation and strong oxidizing medium. Since all industrial enterprises in the world today are looking for measures to reduce environmental pollution, and this "natural" lubricating oil is having this feature, although the cost of vegetable oil is high, the increased cost is enough to offset the environmental treatment costs caused by the use of other mineral oils and synthetic lubricants. Classification according to the nature of crude oil and processing technology
It is divided into paraffin base oil, intermediate base oil and cycloalkyl base oil