Comparative Assessment of the Degradation Behaviour of API 5l X65 And Micro-Alloyed Steels in E20 Simulated Fuel Ethanol Environment

• Published in: Energy procedia 2019-01, Vol.157, p.1320-1327
• Main Authors: Joseph, O.O., Loto, C.A., Dirisu, J.O.
• Format: Article
• Language: English
• Subjects: API 5L X65; corrosion; degradation; E20; micro-alloyed steel; SFGE
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2018.11.297

Presently, bio-fuels are evolving as a significant alternative to tackle the problem of global warming in the world. Fuel ethanol is one of such alternatives employed to reduce the usage of fossil fuels such as petrol. Regardless of the great potentials posed by fuel ethanol in comparison to gasoline fuels, corrosion and stress corrosion cracking (SCC) in the presence of fuel ethanol has recently been recognized and identified as a phenomenon in end-user storage and blending facilities. Predictions on the performance of pipeline steels in fuel ethanol environments, are therefore, needed in solving the ethanol SCC problem. Electrochemical tests have been conducted for API 5L X65 and micro-alloyed steel (MAS) in E20 simulated fuel grade ethanol (SFGE) environment via potentiodynamic polarization and mass loss methods. The tests were performed using simulated E20 fuel grade ethanol with additions of 5 volume percent methanol, 1 volume percent water and 32 mg/L NaCl. Mass loss corrosion rates were very low (generally less than 2 mpy). Results show that the two materials are susceptible to degradation in E20 simulated fuel grade ethanol (SFGE). No significant difference was observed in the mass loss corrosion rates of API 5L X65 and micro-alloyed steels in E20 SFGE. However, morphological observation of the post-corrosion samples and calculated polarization resistance show micro-alloyed steel as more compatible with E20 in this regard.