How is oil refining works?
Oil refining and process involves in oil refining plants is listed below you can easily find it.Refining is a set of operations and treatments (mechanical or chemical) which improve the characteristics of a product and produce a commercial product from a raw product.
Thecrude – or crude oils since it are many types (black, brown, viscous fluids) – can not be used as such. It must undergo refining operations.
In this case, this term designates all the transformations (, cracking, desulphurization, etc.) that the oil undergoes at the outlet of the wells.
Operations that make it possible to separate the different cuts of oil which will then be transformed into various intermediate products (naphtha, for example, a basic ingredient in the manufacture of) or marketable (gasoline, diesel, etc.).
Refining of paper and metals:
Refining operations are also carried out in the paper industry. They correspond to a mechanical treatment (and shearing) applied to the and aim, for example, to improve the printability properties of the papers.
Thecan, too, undergo refining operations (distillation and ) to remove the maximum trace impurities.
The composition of crude oil:
Thecrude is composed of 85% and 10% of . For the rest, it contains various impurities ( , water, salt, and ) that should be removed during to avoid any or fouling problem and to meet regulatory constraints.
Thecrude contains, in varying proportions, four types of that influence the quality of the final products:
- paraffins, linear carbon and hydrogen chains,
- isoparaffins, non-linear carbon and hydrogen chains,
- naphthenes, cyclic hydrocarbons
- and , cyclic hydrocarbons which have double carbon bonds.
Distillation of crude oil:
Theunit operates at a temperature of around 360 ° C and a of around 2 . It separates the oil into different cuts which will form the basis of the final products.
The lower the number ofatoms and the lower the boiling point, the higher the compounds will be in the distillation column. From top to bottom, we therefore find:
- of with a number of carbon atoms between 1 and 4, such as methane,
- naphtha, a with 5 or 6 carbon atoms that will be used in the manufacture of ,
- the which contains between 7 and 11 carbon atoms,
- the having up to 13 carbon atoms
- and diesel, which has up to 25 carbon atoms.
The residues are treated under vacuum in a second distillation column to produce industrial lubricating oils, paraffins, heavyoil and bitumen.
Cracking of heavy hydrocarbons:
After distillation, the proportion of heavy hydrocarbons generally remains high in view of the commercial demand for lighter products. The heavyare therefore broken into several lighter molecules. This is called the cracking operation. It generally takes place at about 500 ° C and in the presence of a . This operation is relatively energy intensive.
Products that need to be improved:
In general, the products resulting from these first two stages will have to undergo additional treatments before they can be marketed.
The gasoline cut, for example, must go through a step of reducing its sulfur content, which must be zero to meet European constraints. The operation takes place in a reactor at temperatures around 400 ° C and at a pressure between 40 and 80 bars. Under these conditions, hydrogen injected into the mixture reacts with the sulfur atoms to formwhich can then be removed. It is also necessary to increase the of this gasoline cut. To do this, the product is injected into a reforming unit. At a temperature of 500 ° C and a pressure of 20 bars, the paraffins and naphthenes are then transformed into aromatics with a higher octane number.
Read it also: