An Investigation on the Performance of an Imidazoline Based Commercial Corrosion Inhibitor on CO۲ Corrosion of Mild Steel

The performance of an Imidazoline based commercial corrosion inhibitor on CO۲ corrosion of mild steel was investigated in a Cl- containing solution employing linear polarization resistance (LPR), potentiodynamic polarization and monitoring corrosion potential techniques. Experimental results showed that an increase of the commercial inhibitor concentration up to ۵۰۰ ppm increases the RP value and produces an efficiency of ۹۰ percent. The increase of a test solution temperature at ۶۰°C caused an increase on RP value compared to RP measured at room temperature this suggests adsorption of the inhibitor is promoted by temperature. Plot of c/θ versus inhibitor concentration (c) using different methods showed a straight line with a slope very close to unity, indicating that adsorption of the investigated commercial inhibitor on steel/saturated CO۲ solution obeys the Lungmuir adsorption isotherm.

Keywords:

CO۲ corrosion , Corrosion inhibitor , Linear Polarization Resistance , potentiodynamic polarization , Lungmuir Adsorption Isotherm