Distinction between Class III base oils and Class II base oils

Category: Saturated hydrocarbon content % Viscosity index vi Sulfur content % (mass fraction).

Class I < 90% 80 120 >

Class II >90% 80 120 <

Class III >90% > 120 <

From the perspective of production technology, the production process of Class I base oil is basically based on physical process, without changing the hydrocarbon structure, and the quality of the base oil produced depends on the content and nature of the ideal components in the raw material. As a result, these base oils are limited in terms of performance.

Group II base oils are prepared by a combination process (a combination of solvent process and hydrogenation process), which is mainly based on chemical processes, which are not limited by raw materials and can change the original hydrocarbon structure. Therefore, the group II base oil has less impurities (aromatic hydrocarbon content less than 10), high saturated hydrocarbon content, good thermal stability and oxidation resistance, and the low temperature and soot dispersion properties are better than those of the class I base oil.

Group III base oils are hydrogenated base oils with a high viscosity index compared to Group II base oils, also known as unconventional base oils (UCBO). Group III base oils far outperform Group I and Group II base oils in terms of performance, especially with a high viscosity index and very low volatility. Some Group III oils are comparable in performance to poly-olefin (PAO), but are much less expensive than synthetic oils.

Group IV base oils are poly-olefin (PAO) synthetic oils. Commonly used production methods are paraffin decomposition and ethylene polymerization. PAO can be divided into low polymerization, medium polymerization and high polymerization according to different polymerization degrees, which are used to prepare different oils.

Compared to mineral oils, these base oils are free of S, P and metals, and because they do not contain waxes, they have a very low pour point, usually below 40, and a viscosity index of more than 140. But the Pao boundary has poor lubrication. In addition, due to its small polarity, its ability to dissolve polar additives is poor, and it has a certain shrinkage to rubber seals, but these problems can be overcome by adding a certain amount of esters.

Synthetic oils (synthetic hydrocarbons, esters, silicone oils, etc.), vegetable oils, recycled base oils, etc., in addition to Group I and IV base oils, are collectively referred to as Class V base oils.

First, the composition is different.

1. A class of base oil: a class of base oil is greater than 90 saturated substances (%).

2. Class II base oil: Class II base oil is not greater than , saturated substance (%) 90.

Second, the production process is different.

1. Base oil category: the production process is basically based on physical processes, without changing the hydrocarbon structure, and the quality of the base oil produced depends on the content and properties of the ideal components in the raw materials. As a result, these base oils are limited in terms of performance.

2. Base oil class II: It is prepared by a combination process (combination of solvent process and hydrogenation process), the process is mainly based on chemical process, not limited by raw materials, and the original hydrocarbon structure can be changed.

Lubricating oil base oils are mainly divided into three categories: mineral base oils, synthetic base oils and vegetable oil base oils. Mineral base oils are widely used in large quantities (about 90% or more), but some applications require the use of synthetic base oils and vegetable oil base oil blends, ester oils are used as high-end lubricating oils.

Mineral oil base oil is refined from **. The main production processes of lubricating oil base oil are: atmospheric and vacuum distillation, solvent deasphalting, solvent refining, solvent dewaxing, clay or hydrogenation supplemental refining.

Class III base oil is prepared by full hydrogenation process, and compared with Class II base oil, it is a hydrogenated base oil with high viscosity index, also known as unconventional base oil. Group III base oils are far superior to Class I and Class II base oils in terms of performance, especially with a high viscosity index and very low volatility. Some of the three types of oils have comparable performance to PAO, but are much cheaper than synthetic oils.

From a technical point of view, the preparation technology of class III oil is a major progress in modern lubricant technology, with this technology, lubricating oil "high-end performance, civilian **" is no longer a dream, and the popularization of high-performance lubricating oil has become possible.

Precautions for three types of base oils.

Oxidation stability and high temperature stability are among the most significant advantages of synthetic oils. It has good oxidation stability and high temperature stability, and the lubricating oil can be used for a longer time.

The high content of unsaturated hydrocarbons and aromatic hydrocarbons makes the stability of the oil poor, and the class III oil is deeply refined, removing a large number of impurities, and the aromatic hydrocarbon content is less than 1%, so the stability of high-temperature oxidation has been improved. The stability of PAO is mainly affected by the amount of paraffin residue.

Synthetic base oil is not directly from petroleum refining, but a base oil obtained after the synthetic processing of petrochemical products.

Hydrogenated base oilsBase oils obtained after hydrotreating mineral oils.

Solvent-refined mineral oilA mineral oil-type base oil obtained by solvent refining.

Other base oils do not fall under the above 3 categories.

Standard base oil refers to the base oil produced according to relevant standards, such as the paraffin-based neutral oil standard, intermediate base and naphthenic base oil base oil standard, and base oil series standards issued by Sinopec Corporation earlier.