We have heard the name of base oil many times. But, do you know what base oil is and how many categories it is divided into? Base oil is a type of oil that is used as a base to produce different oils. The base material is, in most cases, a crude Base oil that has been used and then mixed with other materials to produce oils with specific characteristics, depending on the type of oil being considered.
All lubricants are composed of a base oil. Typically, lubricants consist of 90% base oil and 10% additives. But how do we know which is the best Base oil? Trying to choose between mineral (natural) and synthetic oils can be confusing.
We all know that different oils, including engine oil, hydraulic oil, etc., are all used to lubricate car parts and industrial machines. Base oil is used as a raw material in all these lubricants. All lubricants follow a simple formula (Base oil + additives). The only difference between oil and grease is that grease has an additional thickener. About 30% of grease is made up of a thickener (a simple or complex soap).
Base oil is used for lubrication and is produced from refining crude oil (mineral base oil) or through chemical synthesis (synthetic base oil). Based on the “American Petroleum Institute (API)” classification, base oils can be classified into 5 groups. Group I, II and III are from crude oil (mineral oil), Group IV is a fully synthetic oil and Group V is for all Base oils. They are characterized by saturation level, sulfur level and viscosity index.
Saturates are a type of molecule commonly found in base oil. They occur naturally in the Base oil. However, higher levels of saturation are achieved during the refining process. If the level of saturation is higher, the molecular bond of the oil is stronger. This increases resistance to fracture and oxidation or loss of viscosity.
Sulfur is a natural mineral found in crude oil. This material reacts with oxygen and can be harmful to the performance of the oil. Also, due to being an effective antioxidant, sulfur improves oxidative stability. When the amount of sulfur is less, its purity is better. It means that it reduces the possibility of corrosion and oxidation.
Viscosity index refers to changes in viscosity compared to oil temperature. Viscosity is measured at 40°C and 100°C. When the viscosity index is high, the changes with the temperature difference are less. All oils increase in viscosity with decreasing temperature and decrease in viscosity with increasing temperature.
All Base oils have characteristics that determine how well they withstand lubrication challenges. Industrial oil, whether mineral-based or synthetic-based, is designed in such a way that it has a specific application. Some of the features that should be present in a Base oil are:
Thermal and chemical stability: The base oil must have good thermal and chemical stability to be used in heat and high pressure conditions.
Neutralizing properties: The Base oil must have good neutralizing properties so that it can be used in the production of chemicals and automotive accessories.
The ability to absorb and disperse additives: the base oil must have the ability to absorb and disperse additives so that it can be used in the production of different oils.
Insolubility with water: The Base oil must be insoluble in water in order to be used in humid conditions.
Ability to resist oxidation: The base oil must have good resistance to oxidation and polymerization so that it can be used in long-term conditions.
Chemical and physical stability: The base oil must have good chemical and physical stability to be used in long-term conditions.
Preservation of properties at low temperatures: The Base oil must maintain its properties at low temperatures in order to be usable in cold conditions.
In fact, base oils are classified as one or more of these five API groups before any additives are added to the mix:
Group I
As saturated oils less than 90%, sulfur more than 0.03% and with a viscosity index range of 80 to 120 are classified. This oil is obtained from crude oil. Therefore, they are the cheapest base oils available. Group I Base oils are obtained from the solvent extraction method, which results in the production of an oil with irregular molecules, which increases friction within the oil.
Group II
These oils are defined with more than 90% saturation, less than 0.03% sulfur and with a viscosity index of 80 to 120 and are usually made by hydrocracking, which is a more complex process than the Group I base. Hydrocracking is a process that breaks down large hydrocarbon molecules into smaller molecules. As a result, it gives them better antioxidant properties. The price of group II oils is close to that of group I oils.
Group III
These oils are more than 90% saturated, less than 0.03% sulfur, and have a viscosity index above 120. This longer process is designed to achieve a purer base oil. More pressure and heat are applied during the refinery process. That is, they are more resistant to oxidation than Group I oils. Also, like the Base oils of the second group, these oils are also increasing.
Group IV
Group IV base oils are polyalphaolefins. That is, the main synthetic base industrial oils used in industrial and automotive oils. These synthetic Base oils are made by humans through a process called synthesis. They have a much wider temperature range. They are perfect for use in cold and hot conditions. Also, they are significantly more expensive than Group III base oils.
Group V
Group V base oils are classified as all other base oils. Including silicone, phosphate ester, polyalkylene glycol, polyester, biolobes, etc., the oils of this group can be more useful at higher temperatures. Even compared to synthetic base oil, they provide an excellent detergent that increases the hours of use. Usually, group V oils are not used as Base oils, but these oils are used as an additive to other Base oils.
Generally, base oils are used to produce fluids and other oil products. So we must say, Base oil is used in the production of lubricating greases, various products that require oil and its compounds, motor oil, etc.
Base oil is one of the primary and basic materials for the production of various oil and petroleum derivatives and is mostly used in the automotive industry. The amount of this oil to produce other fluids depends on their type. Types of Base oils, according to their compositions and characteristics, affect the viscosity, oxidation and solvent power of other oils such as motor oil. The only difference between these types of Base oils is that they determine the level of lubrication and resistance of different oils.
