Base oils are used to manufacture products including greases, engine oil and metalworking fluids. Different products require different compositions and properties of the oil. One of the most important factors is the viscosity of the liquid at different temperatures. Whether a crude oil is suitable for producing a base oil or not depends on the concentration of the base oil molecules and how easy it is to extract them.
Base oil is made by refining crude oil. This means that crude oil is heated so that different distillates can be separated. Light and heavy hydrocarbons are separated during the heating process – the light ones can be refined into gasoline and other fuels, while the heavier ones are suitable for bitumen and base oils.
Chemical substances – additives – are added to the base oil in order to meet the quality requirements for the end products with regard to, for example, friction and cleaning properties. Certain types of engine oils contain more than twenty percent additives.
There are large numbers of crude oils all around the world that are used to produce base oils. The most common one is a type of paraffinic crude oil, although there are also naphthenic crude oils that create products with better solubility and very good properties at low temperatures. By using hydrogenation technology, in which sulfur and aromatics are removed using hydrogen under high pressure, you can obtain extremely pure base oils, which are suitable when quality requirements are particularly stringent.