CO₂ Corrosion Inhibitors Performance at Deposit-Covered Carbon Steel and Their Adsorption on Different Deposits

The efficiency of inhibitors to prevent under deposit corrosion of carbon steel and their adsorption on aluminum oxide, calcium carbonate, and silica sand deposits have been evaluated using electrochemical measurements and UV-visible spectroscopy. 2-Mercaptopyrimidine provided the highest corrosion protection on both bare and deposit-covered steels. In contrast, 1-Dodecylpiridinium chloride had minimal adsorption on all deposits, but it exhibited insufficient performance. Inhibitors adsorption tended to be related to the inhibitor type and not notably to the physical properties of the deposits. Deposit porosity, layers thickness, and depletion of the inhibitor by adsorption on deposits could not be linked entirely to corrosivity and inhibitors performance.