Photo Oil refinery : principles and operation !
28 Aug 2018

Oil refinery : principles and operation !

The oil refinery is a key industry in oil development.  This article offres a zoom on its principle and its operation.

Principles of the oil refinery

Definition of refining

Petroleum refining is the industrial process that makes it possible to obtain the main energy derivatives of oil such as gasoline, diesel, or heavy fuel oil. Refining is a complex process within a refinery that involves the mobilization of a large infrastructure costing millions or even billions of dollars. The Skhira refinery in Tunisia is valued at $ 2 billion.

Why is a refinery needed?

The installation of a refinery makes it possible to meet a technical need: in particular, because the oil is still unusable in its raw state. The refinery also has a commercial purpose by aiming to extract the high value products contained in the crude oil. Apart from this, note that refining is also useful for separating non-energy products from petroleum namely naphthas, lubricants and bitumen.

Modern refinery techniques

Today, refining is no longer limited to the separation of major hydrocarbons. Final product optimization steps are also involved in the process. The big African oil industries such as Tunisian Tarek Bouchamaoui are in charge of processing, mixing and improving.

Operation of an oil refinery

What is a refinery?

A refinery is a huge industrial infrastructure managed and supervised by the refinery operator. It uses employees specialized in the oil business: petroleum engineers and supervisors, among others. It contains 3 main plants: separation, conversion and improvement plants.

The functions of the separation plant

The first plant (separation) is the one that receives the crude oils from the extraction pipeline. It contains atmospheric distillation equipment to separate molecules according to their weight. When it comes out, the various oil derivatives are already obtained, from the heaviest (such as bitumens) to the lighter and more volatile ones (like gases).

The functions of the conversion plant

The second plant of the refinery carries out successive operations at the first. Called a conversion factory, it performs the tasks of obtaining even lighter products. Note that after the separation, the derivatives are still too heavy. Therefore, each product must undergo another molecular separation procedure called catalytic cracking.

The functions of the improvement plant

At the exit of the factory number 2, the oil derivatives are already operational. However, to meet the expectations of the market, they must undergo a final treatment, a stage of improvement. The latter consists in eliminating any corrosive molecule present in each product in order to arrive at the products distributed in the gas stations.

The oil refinery in Africa

The largest refineries in Africa

New oil territory, Africa contains several refineries of high quality :

  • The Aliko Dangote Refinery : The world's richest Nigerian refinery, built on a $ 9 billion budget, is one of the largest refineries in Africa.
  • The Qalaa refinery: valued at $ 3.7 billion, the Qalaa Holding refinery in Egypt reduces the country's oil import by 50%. Thanks to its position as the 3rd largest oil producer in Africa, Egypt attracts investors from all over the world. There are major oil companies such as Qatar petroleum or HBS Tarek Bouchamaoui.
  • The Skhira refinery: the largest refinery in Tunisia valued at $ 2 billion.