There are a lot of philosophies regarding chemical desalting aids. Depending on what the objective of the program is, any of them can work better. Just like they do in properties, crude slates vary significantly in contaminates, why is why there is no one-size-fits-all solution. A primary emulsion breaker is often injected into the crude oil. Though it has become the standard for desalting operations, adjunct chemistries may also be used. For instance, a water clarifier can be used to remove oil from effluent water before processing at the wastewater plant.
Advantages of Adding Caustic to Desalter
Adding caustic to the desalter has multiple advantages. Magnesium and calcium chloride, if they are able to escape, hydrolyze and create the potential for corrosion. Caustic reduces the risk of corrosion in the crude unit overhead by converting hydrochloric acid formed to sodium chloride, which does not hydrolyze at crude unit temperatures.
Caustic can help in breaking hard emulsions. It ensures that less contaminated water is carried over into the crude unit and hence, reduces fouling and corrosion potential.
Caustic can also aid in iron removal at the desalter and the process can be controlled by pH. The addition of caustic forces iron from the oil and removes it from the system in the effluent water. Iron removal not only decreases fouling potential but also helps in increasing the value of coke.
Desalter Acidification to Combat Amines
Amines can lead to a variety of problems. They usually originate from triazine-based H2S scavengers added to reduce safety and environmental hazards. The risk with amines is that if they make it through the desalting process along with salts, they can form highly corrosive amine chloride salts. Acidifying the desalter can avoid the problem, preventing corrosion.
DeSalters LLC for Desalters & Services
Oil refineries in TX requiring desalters or servicing, reach out to DeSalters LLC! We have top-solutions available to optimize plants and processes and increase their operational efficiency.