An Electrochemical Investigation on the Effect of Heat-Stable Salts on the Corrosion Resistance of Carbon Steel in MDEA Solution

Subject Areas :

Hojatollah Abnavi ¹ , Esmaeil Jafari ²

1 - Materials Science and Engineering Dept., Shiraz Branch, Islamic Azad University, Shiraz, Iran, Fax Number: [phone]
2 - Materials Science and Engineering Dept., Shiraz Branch, Islamic Azad University, Shiraz, Iran, Fax Number: [phone]

Received: 2021-08-15 Accepted : 2021-10-07 Published : 2021-08-01

Keywords: Carbon Steel, MDEA Solution, Heat Stable Salts, Polarization Resistance,

Abstract :

The purpose of this study is to identify the influence of different concentrations of heat-stable salts (oxalate, acetate, formate, succinate, glycolate) on the carbon steel corrosion in MDEA solution. Natural gas usually contains acidic gases like CO2 and H2S along with other sulphur components. These acidic gases have to be scrubbed off from the gas for environmental, operational, and economic reasons. A long-term experiment was conducted to investigate the corrosion behavior of carbon steel in HSS+MDEA solutions and surface analysis techniques (SEM, EDS) were carried out to characterize the morphologies and compositions of the surface layers. To obtain the corrosion behavior of carbon steel in different concentrations of HSS+MDEA solutions the potentiodynamic polarization tests were used. The result showed that the acetate had less corrosion effect and the oxalate had the greatest impact on corrosion of the carbon steel. According to the electrochemical results, these five heat stable salts didn’t have a significant corrosion effect on carbon steel till 5000 ppm concentration.

References:

[1] Kohl, A. and Richard, N. 1997. Gas purification, Gulf Professional Publishing.

[2] Tanthapanichakoon, A. W. 2006. Electrochemical Investigation on the Effect of Heat-stable Salts on Corrosion in CO₂ Capture Plants Using Aqueous Solution of MEA,  Industrial & Engineering Chemistry.

[3] Khorrami, M. R., Raeissi, K., Shahban, H. and Torkan, M. A. and Saatchi. A. 2008. Corrosion Behavior of Carbon Steel in Carbon Dioxide-Loaded Activated Methyl Diethanol Amine Solution. Corrosion. 64 (2):124–130.

[4] Haws, R. Contaminants in amine gas treating. 2001. CCR Technologies inc.

[5] Dong, B., Zeng. D., Yu, Z. and Tan, S. 2019. Effects of heat-stable salts on the corrosion behaviours of 20 steel in the MDEA/H2S/CO2 environment, Corrosion Engineering, Science and Technology. 54(4):339-352.

[6] Ling H., Liu, S. , Gao, H.  and Liang, Z. 2019. Effect of heat-stable salts on absorption/desorption performance of aqueous monoethanolamine (MEA) solution during carbon dioxide capture process. Separation and Purification Technology. 212:822-833.

[7] Durrani, M., Haija, M. and Rangaraj, M. K. 2019. Removal of heat stable salts from aqueous MDEA solution via electrosorption using carbon-based electrodes. International Journal of Greenhouse Gas Control. 85:160-173.

[8] Achazhiyath, A., Alhseinat, E. and Banat, F.  2019. Removal of heat stable salts from industrial lean methyldiethanolamine using magnetic alginate/iron oxide hydrogel composite. International Journal of Greenhouse Gas Control. 83:117-127.

[9] Krajangpit, W., Supap, T.,  Muchan, P.,  Saiwan, C.,  Idemb, R. and Koiwanit, J. 2019. Solvent extraction based reclaiming technique for the removal of heat stable salts (HSS) and neutral degradation products from amines used during the capture of carbon dioxide (CO2) from industrial flue gases. Separation and Purification Technology. 228:44-57.

[10] Arora, N., Banat, F. and Alhseinat, E. 2019. Capacitive deionization performance of CNTs-Si-Ag based electrodes for the removal of heat stable salts from methyldiethanolamine (MDEA) solution in natural gas sweetening units. Chemical Engineering Journal. 356:400-412.