Evaluation of Phosphate Tridecyl Ethoxylate Triethanolamine Salt as a Corrosion Inhibitor in CO₂-O₂ Environment for Carbon Steel

Investigation of corrosion inhibitors on CO₂-saturated aqueous solution with O₂ contamination is limited. Hence, this study investigated the corrosion behavior of phosphate ester inhibitor towards carbon steel corrosion in a simulated CO₂-O₂ environment by potentiodynamic polarization technique and electrochemical impedance spectroscopy. It was shown that the PE prevents the corrosion attack in the presence of CO₂-O₂, reaching an efficiency of 90.7% with 25 ppm in 3.5 wt% NaCl solution at 25 ^oC. Furthermore, the superficial characterization of carbon steel was studied by scanning electronic microscopy which supported that the inhibitor protects against corrosion. The varying temperatures showed that PE adsorbed on the steel surface by a physical process and obeyed the Langmuir isotherm.

Keywords:
Inhibitor; phosphate ester; CO₂ corrosion; O₂ corrosion