This type of reagent is used in fractionating columns to protect overhead lines from corrosion caused by the presence of salts (mainly chlorides), sulfur compounds, etc, which decompose with formation of volatile acids.
There are two technologies for the application of corrosion inhibitors (CIs): film-forming inhibition and neutralization of acid molecules. Inhibition and neutralization are particularly important because without proper application, the corrosion process will be going on. If process will be inhibited without neutralizing or vice versa, corrosion will not be controlled.
The purpose of the neutralizer is to react with acids (usually based on strong acids (HCl, H2SO4, thiosulfate, etc.), neutralizing them. As a result, the corresponding salts are formed and the pH of the condensed water is raised to a "safe" zone.
The corrosion inhibitor covers the metal surface with a protective film, reducing the level of influence of corrosive agents on the metal surface to a minimum.