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

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. (c) 2013 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.