What is Base Oil? An Overview of Base Oil Knowledge

If you intend to explore and enter the lubricant business, you have likely heard the term "base oil." This is a crucial component of various lubricants today. So, what is base oil? What are the different groups of base oil? How are they classified? Join Huynh Chau Lubricants as we delve into these topics in the following article.

Base oil plays an important role in lubricant products.

1. What is base oil?

Base oil is a familiar concept for lubricant distributors. Base oil is produced through the refining of crude oil (also known as mineral oil). The process of creating base oil includes various treatment methods and different physical and chemical processes. Base oils refined through hydrocarbon synthesis from crude oil are referred to as synthetic oils.

The process of creating base oils involves multiple stages.

Base oil is an essential component that accounts for 80-85% of current lubricants. Chemical additives are subsequently added to the base oil to meet quality requirements for the final lubricant product, such as reducing friction and providing cleanliness.

2. Groups of base oils

Currently, base oils are divided into five main groups:

There are five groups of base oils.

• Group I

Base oils in this group are created through solvent refining processes that remove weak chemical structures or harmful agents (such as cyclic structures and double bonds) from crude oil. Group I base oils have a sulfur content (sulfuric acid) > 0.03% (300 ppm), a low paraffinic and naphthenic component (open-chain or cyclo-saturated structures) of less than 90%, and a viscosity index ranging from 80 to 120.

The refining process for Group I base oils is quite simple, making them the cheapest base oils on the market today. Due to containing many cyclic structures, sulfur, and nitrogen, Group I base oils typically have an amber or brownish-yellow color.

• Group II

Group II base oils are produced by combining solvent processing with hydroprocessing technology (hydrocracking). In this process, hydrogen gas is used to eliminate undesirable components from crude oil. Compared to Group I base oils, Group II oils have fewer cyclic structures, sulfur, and nitrogen.

Group II base oils have a sulfur content < 0.03%, a saturation level above 90%, and a viscosity index between 80 and 120. This type of oil exhibits better oxidation stability and is clearer than Group I base oils. Currently, Group II base oils are quite commonly used in the lubricant market due to their price being very close to that of