Effect of carbon dioxide on corrosion of tubular steel in high hydrogen sulfide and carbon dioxide environments

Abstract

Purpose

The present work primarily aims to study the corrosion characterization of tubular steel API‐P110 in high H₂S containing solution with or without CO₂.

Design/methodology/approach

Corrosion behaviors of steel in buffered solutions containing 50 percent H₂S and various levels of CO₂ concentration were investigated via weight‐loss method, SEM and EDS. The effects of CO₂ on corrosion occurred on the metal were analyzed by electrochemical techniques.

Findings

Corrosion rates of steel decreased as the CO₂ content in H₂S/CO₂ solution increased. It was observed for the tubular steel to experience an increase in corrosion rate at concentrations 17 percent CO₂ or 34 percent CO₂ in 50 percent H₂S while when further increasing concentration of CO₂ to 50 percent the corrosion rate decreases. Increased CO₂ content in H₂S/CO₂ led to fewer anions desorbing and fewer reactants adsorbing, e.g. H+, H₂CO₃. As a result, cathodic reaction rate decreased and the amount of hydrogen absorbed decreased.

Originality/value

The experimental results showed that corrosion alleviated when increasing CO₂ content in high H₂S and CO₂ containing environment.

Citation

Deng, H., Li, C. and Cao, X. (2011), "Effect of carbon dioxide on corrosion of tubular steel in high hydrogen sulfide and carbon dioxide environments", Anti-Corrosion Methods and Materials, Vol. 58 No. 4, pp. 196-204. https://doi.org/10.1108/00035591111148911