We’ve looked at some of the different types of lubrication that are made, and what specific purpose each serves. For this blog we’re going to focus in on oil lubricants and examine the basics of how these fluids are made as well as what they’re made from.
Lubricant oils are one of many derivatives of raw petroleum. Petroleum in its raw form is a liquid, which varies in colour depending on its source, but is typically somewhere in the yellow/brown/black spectrum. It is composed of hydrocarbons. These are organically existing chemical compounds which are made purely from combinations of carbon and hydrogen atoms- hence the name.
During the process of sedimentation, many immediate impurities in the oil are removed as they form a sediment, equally because of the insolubility of oil, it also separates from any water present in the sedimentation process, meaning the oil which then goes on to be processed is separated from many of the initial contaminations with which it leaves the ground.
The most valuable uses of raw petroleum are extracted by fractioning columns. Because the different hydrocarbons within the raw petroleum mix all have different properties, they cool and condense at different rates. This means that the component parts of the petroleum come of the fractional distillation tower at different heights. Petrol fuel, known as Gasoline in the US, comes of the tower the highest and is a high value product of raw petroleum.
Most of the oils used in lubricants are made using the crude oil which is filtered from lower in the tower. The crude oil is filtered to remove remaining impurities which have not been separated from the crude oil during the ‘fractioning’ or the sedimentation processes. Often the purity of the oil during this process can be viewed through sight glasses in the pipes of the filtering process, such as these.
Although the crude oil at this early stage does have many of the qualities which are required of a lubricating oil, further processing is still required to enhance the fluid, ensuring it can perform all the functions required of it. It is at this stage that additives are introduced to the crude oil. These include allowing the oil to be resistant to extreme temperatures, for example ensuring the oil won’t freeze at low temperatures.