The inhibition of CO2 corrosion of N80 mild steel in single liquid phase and liquid/particle two-phase flow by aminoethyl imidazoline derivatives

The inhibitory behaviour of 2-undecyl-1-aminoethyl imidazoline (AEI-11) and 2-undecyl-1-aminoethyl-1-hydroxyethyl quaternary imidazoline (AQI-11) on CO2 corrosion of N80 mild steel in single liquid phase and liquid/particle two-phase flow was investigated using weight loss, linear polarization, potentiodynamic polarization, EIS methods and SEM observations. The two compounds inhibited the CO2 corrosion of N80 steel and the extent of inhibition was dependent on the flow conditions and particulate content. In both phases, AQI-11 exhibited better inhibition ability than AEI-11 due to the polycentric adsorption sites on its structure. Theoretical calculation on the inhibition abilities of the compounds and their modes of adsorption are reported.