Caustic soda in the refinery

Caustic soda in the refinery

As important industrial units in the process of converting crude oil into various products, refineries play a very important role in energy and chemical requirements. In refineriery, it is necessary to use chemical compounds to improve the quality and efficiency of polishing. One of these compounds used in refineries is caustic soda or sodium hydroxide. Caustic soda used in the refinery for many reasons. In this article, we are going to examine the uses of caustic soda in refineries, stay with us.

What is a refinery?

A refinery is a type of industrial unit that is used to process and purify crude oil, natural gas and other petroleum products. The main purpose of refineries is to convert petroleum raw materials into products such as gasoline, diesel, diesel, kerosene, bitumen, liquefied gases and other petroleum products.

Refinement process

The refining process in refineries includes different stages, which are generally:

  1. Fractionation Towers: In this step, crude oil is separated into various components, including gases, gasoline, kerosene, and bitumen.
  1. Purification: This stage includes processes such as mechanical purification, chemical purification and thermal purification, which are used to remove impurities and suspended particles in petroleum raw materials.
  1. Conversion: In this stage, petroleum raw materials are subjected to various chemical and physical processes to be converted into final products such as gasoline, diesel and other petroleum products.
  1. Re-refining: In this stage, final products are subjected to processes such as purification and quality enhancement to be presented to customers.

Refineries play a very important role in the oil and energy industry, because they enable the production and supply of petroleum products to the market. Also, these units are important for reducing environmental pollution, because in the refining process, the pollutants in the petroleum raw materials are removed.

Application of caustic soda in the refinery

Caustic soda or sodium hydroxide is one of the important chemical products that has different uses in different industries. Caustic soda is also used in refineries to perform various steps. In the following, we will examine some of the applications of caustic soda in the refinery:

oil refining

One of the important uses of caustic soda in refineries is in the oil refining process. Caustic soda is used to remove organic acids as well as hydrocracking and hydrotreating in order to produce cleaner fuels. Hydrocracking:

  • Hydrocracking:

Hydrocracking is an oil refining process in which heavy petroleum raw materials and high molecular weight promolecules are converted under pressure and in the presence of catalysts and hydrogen. This process is used to improve the quality and increase the extraction capability of petroleum products.

In the hydrocracking process, heavy petroleum raw materials are directed to refinery units under pressure and in the presence of catalysts and hydrogen. In this process, hydrogen atoms actively react in the reactor with petroleum raw materials and catalysts. These reactions lead to the breakdown of lignins, alkanes, aromatics and other molecular details in crude oil. Finally, larger molecules are converted into smaller, more usable molecules as output materials.



The hydrocracking process is dual purpose. First, it reduces the molecular weight of petroleum raw materials, which improves quality and reduces sulfur and nitrogen content. Second, it facilitates the production of high-value products such as high-quality gasoline, diesel, and diesel. As an important process in the oil refining industry, hydrocracking improves the quality of final products and also increases the production of light and usable fuels.

  • Hydrotreating:

Hydrotreating is one of the important processes in the oil refining industry. In this process, petroleum raw materials or petroleum products are refined and strengthened using hydrogen and in the presence of catalysts, under pressure and at high temperatures.

The main purpose of hydrotreating is to remove pollutants in petroleum raw materials and petroleum products. These pollutants can include sulfur, nitrogen, heavy metals and aromatic compounds that can lead to the contamination of petroleum products and the formation of airborne particles.

In the hydrotreating process, hydrogen actively reacts with the pollutants in the crude oil. These reactions lead to the destruction and analysis of pollutants, and as a result, sulfur, nitrogen and aromatic pollutants are reduced. Also, this process can convert unwanted and incompatible carbons into light and usable hydrocarbons.

By implementing the hydrotreating process, petroleum products such as gasoline, diesel and other light products are improved in quality and the amount of harmful pollutants in them is significantly reduced. As an important process in the oil refining industry, hydrotracking improves the quality of final products, increases compatibility with environmental standards, and improves the performance of fuels.

get water

Caustic soda is also used in refineries for water purification. By adding caustic soda to water, acids and heavy metals in water are removed. This process is done as a water purifier before it is used in other refinery processes.

Cleaning parts

In refineries, caustic soda is used to clean parts and equipment. This substance acts on machine and steel parts with strong degreasing power and alkali properties and removes deposits from the surfaces of the parts. In some refinery units, they may be present as heavy oils, organic and inactive sediments, and solid particles. By using caustic soda, these fats and deposits are removed well and the quality of the products is improved.

pH adjustment

Caustic soda, as a strong alkaline substance, is used in some refinery processes to adjust pH. Proper pH is very important in some chemical and refining processes, and caustic soda can be used as a pH regulator.


pH adjustment

Removal of acids

One of the main uses of caustic soda in the refinery is to remove organic acids in crude oil. These acids may cause harmful properties to the final products due to the presence of phenolic, carboxylic and sulfonic groups in crude oil. By adding caustic soda to the refining process, these acids are converted into inactive and harmless substances by creating an oxidative reduction reaction. This process improves the quality of the final products.

Improving the properties of fuels

Caustic soda may be used as a high performance catalyst in refining processes such as hydrocracking and hydrotreating. These processes improve the properties of fuels, such as a dramatic increase in the C-number index (cetane number) in diesel fuels and a dramatic decrease in octane (octane number) in gasoline fuels. Caustic soda acts as a catalyst in these processes and accelerates chemical reactions, which improves the quality of final fuels.

Reduction of sulfur compounds

Petroleum products may contain high sulfur compounds that can be released into the air, forming acids and polluting the environment. By using caustic soda in refining processes such as desulfurization (sulfurization), sulfur compounds can be reduced to an acceptable level. This reduction of sulfur compounds improves the quality of refined products and reduces their consumption and harmful effects.

These are just a few of the applications of caustic soda in the refinery that we have explained above. In general, caustic soda in refining processes has several effects that improve the quality of final products. which includes acids, adjusting pH, removing consumptions, improving the properties of fuels and reducing sulfur compounds.

final word

As an important chemical substance in refineries, caustic soda has many uses. Its applications include oils & fuels refining, water purification, parts and equipment cleaning, and pH adjustment. Using caustic soda in these processes improves the quality of products and increases refining efficiency. This material is one of the most important chemical compounds used in industry and refineries due to its strong alkaline properties and soluble in water. At the end, you can contact our experts for advice and purchase of causic soda flakes 98.5%.

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