Investigation of the corrosion inhibition performances of various inhibitors for carbon steel in CO2 and CO2/H2S environments

Abstract

ABSTRACT The corrosion inhibition performances of thiourea (TU), l-cysteine (CYS), sodium dodecyl sulfonate (SDS), tetradecyl trimethyl ammonium bromide (TTAB), N-benzyl pyridinium chloride (BPC) and imidazoline quaternary ammonium salt (IAS) in CO2-saturated and CO2/H2S coexistent brine solutions were investigated by electrochemical measurement, weight-loss test, molecular dynamics simulation and SEM observation. The results show that H2S can remarkably affect the adsorption of some inhibitors on the steel surface and the inhibition performance. In detail, the inhibition performances of TU, CYS and SDS, which are effective in the CO2 environment, deteriorate in the CO2/H2S environment. However, the cationic inhibitors (TTAB, BPC and IAS) exhibit good inhibition performance in the CO2/H2S environment possibly because of a relatively strong interaction between inhibitor cations and HS− ions. The finding of this study delivers a provable method to predict the performance of inhibitors in the aggressive solution containing H2S.