Analysis of adsorption of carbon steel corrosion inhibitor in model stratum waters by polylogarithmic isotherm

Abstract

Using the methods of gravimetry, potentiodynamic polarization, and impedance spectroscopy, the protective effectiveness of the inhibitory composition INCORGAZ-111 with respect to hydrogen sulfide corrosion of carbon steel St3 in NACE and Samotlor oil field model stratum waters has been studied. Surface coverage is determined on the basis of the electric double layer capacity in presence of the inhibitor. Its adsorption is interpreted using the polylogarithmic isotherm with a big energy gradient of adsorption centers, that indicates linear energy heterogeneity of the surface. The constants of adsorption equilibrium, the energy gradient and the energy dispersion of adsorption centers as well as adsorption free energy were calculated.