Glycyrrhiza glabra extract as an eco-friendly inhibitor for microbiologically influenced corrosion of API 5LX carbon steel in oil well produced water environments

Abstract

In this study, the anti-biocorrosion potential of Glycyrrhiza glabra (GG) aqueous extract for API 5LX carbon steel in the presence of different corrosion causing bacterial strains is evaluated. Biocorrosion experiments are performed by using both weight loss study and electrochemical analysis including AC-impedance and potentiodynamic polarization. The bioactive molecules in the GG extract are confirmed using Fourier transform infrared spectrum (FT-IR). Both surface coverage and adsorption isotherm analysis confirm adsorption of GG inhibitor over the metal surface. Electrochemical analysis and surface analysis are confirmed mode of inhibition in detail. The inhibition efficiency is calculated from both weight loss and impedance data's and found 92% and 99.8% for the mixed consortia system added with 600 ppm of GG inhibitor, respectively. SEM analysis confirms that both abiotic and biotic systems are affected by severe pitting type of corrosion reaction and the addition of inhibitor molecules suppressed the corrosion problems by forming a protective layer over the carbon steel surfaces.