Effect of succinic acid on carbon steel corrosion in produced water of crude oil

• Succinic acid is an efficient corrosion inhibitor for C-steel in produced water.
• The inhibition efficiency is maximum at concentration of 50 ppm and at pH = 3.
• Succinic acid was found to act as a mixed-type inhibitor.
• The corrosion inhibition is attributed to physical adsorption.
• Succinic acid follows Temkin adsorption with negative values of ΔGads0.

Succinic acid has been evaluated as a corrosion inhibitor for carbon steel corrosion in produced water of crude oil using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and FTIR techniques. The results showed that the inhibition efficiency increased with increase in succinic acid concentration but decreased with rise in temperature. The best inhibition efficiency was obtained by adding 50 ppm succinic acid at pH 3. Inhibition efficiency values obtained from polarization and EIS are in reasonably good agreement. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated and discussed. Polarization curves showed that the succinic acid act as a mixed-type inhibitor. The corrosion inhibition is attributed to physical adsorption of the succinic acid on the carbon steel surface. Succinic acid adsorption follows Temkin isotherm with negative values of adsorption free energy. Succinic acid adsorption on the electrode surface was fast and completed within 30 min.