22 | MAY | 2019
Molecules to improve oil refining
Oil platform and two vessels are seen off the coast of Louisiana, in the Gulf of Mexico - Photo: Gerald Herbert/AP

Molecules to improve oil refining

Mexico City
Rafael López
-A +A
Scientist from UNAM have developed surface-active molecules to purify petroleum and make refinery processes more efficient

The National Autonomous University of Mexico (UNAM) has been working to improve oil refinery processes. A group of investigators from the Faculty of Chemistry, led by Jesús Gracia Fadrique, has developed two molecules to free black gold from impurities.

The development of these molecules was possible through a research that won first place at the Program for Promoting Patenting and Innovation (PROFOPI) of UNAM.

These molecules, which are known as surface-active among physicists, have a specific function: To eliminate water droplets and electrolytes found in petroleum.

“In its natural state, crude oil cannot be used in refineries because the water droplets and electrolytes it contains causes the corrosion and contamination of catalysts during the distillation process. Consequently, before refining crude oil to obtain gasoline and gasoline sub-products, it is absolutely necessary for these materials to be removed,” said the university investigator.

Certain compounds with a very high molecular weight structure known as asphaltenes can be found in petroleum; their purpose is to stabilize the level of water droplets in the substance. These distillation residues are used to produce asphalt roads and bridges.

The molecules developed by the Faculty of Chemistry of UNAM displace the oil’s natural molecules, which allows for the water droplets to come together in one place for further separation. Thus, in separating the water, the emulsion breaks and the hydrocarbon becomes free of water and soluble salts.

There are some international standards that allow for a small number of water droplets to be present in crude oil since they can never be completely removed; all in all, a removal of this kind ensures a greater level of purity for the hydrocarbon.

“Our molecules can compete with other similar products in the international market. With this technology development, we have gained a high efficiency in crude oil conditioning,” Gracia Fadrique commented.

In oil deposits that are near aquifers and underwater reserves, clays, salts, and other materials abound. Upon exposure to these substances, the water emulsifies in little drops within the crude oil, which enables it to absorb electrolytes such as sodium chloride, magnesium, etc.

“This type of water may contain 50 to 100 times more electrolytes than sea water, which is why it must be extracted from the oil,” the investigator explained.

Since water droplets spread in petroleum are somewhat stable, it’s not enough to leave them resting for them to be separated. Chemical agents with surface activity and electric fields must be added so that, as they collide, they may reunite and form bigger droplets until eventually, the water separates completely. The speed of this process depends on the hydrocarbon’s density. Furthermore, there are clays and other solubilized materials in the water that must also be removed from the petroleum.

Before the oil is taken to a refinery, these two molecules, developed by UNAM investigators, are applied to the substance. At this stage of the process, other instruments are required, such as electrostatic precipitators that use high voltage and intense current flows in order to increase the coalescence capacity.

The molecules developed at the Faculty of Chemistry of the National Autonomous University of Mexico are soon to be applied in the oil extraction industry of Mexico.

“Wherever there’s an oil well, these molecules will be needed. Any kind of petroleum has to be treated with them before entering refineries. In an oil country such as this, it is imperative that we apply this kind of technology in our extraction processes,” Jesús Gracia Fadrique stated.



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