Application of simulation technique on studies of ammonium salts corrosion in oil refining plants

Process simulation and heat exchanger simulation are applied as design tools for oil refining plants. Calculation accuracy has been enhanced and these techniques have been generally used. On the other hand, electrolyte thermodynamic model has been practically used to predict corrosion environment recently. Many case studies using this model are reported. Corrosion caused by ammonium salts such as NH4Cl or NH4HS is one of the serious issues in oil refining plants because corrosion rate can reach several mm per year in the concentrated ammonium salts solutions and it is difficult to predict corrosion rate. This is because it is quite difficult to predict localized corrosive environment in the plant. Thus, employment of electrolyte thermodynamic model is helpful to evaluate localized corrosion environment. This paper describes some examples that simulation technique was applied to study ammonium salts corrosion.