While we all know that crude oil contains high amounts of hydrocarbons, few realize the oil also contains water, chloride salts and other impurities. The hydrochloric acid formed by the Chlorides and other impurities can readily corrode equipment throughout the refining process. As a result, the desalting process is crucial to crude oil refining.
Organic chlorides are compounds which contain a carbon-chlorine bond. Examples of these compounds include chloroform and chlorobenzene. Organic chlorides present a more significant problem in crude oil refineries as compared to inorganic chlorides since they are not removed through the desalting process. While these compounds are generally not present naturally, the oil can be adulterated when additives, cleaning solutions or chemicals for oil recovery are used.
As a result, refineries typically do not accept crude oil that contains more than 5 parts per million (μg/g) of organic chloride.