Corrosion of T2 copper in E50 ethanol gasoline blends and corrosion inhibition by Turkish red oil

• Assessing ethanol-petrol blends as sustainable fuel alternatives . • Modeling corrosive byproduct impacts on copper . • Turkish red oil: Sulfonated castor derivative with green chemistry compliance. • Electrochemical/SEM/AFM/XPS analyses reveal copper corrosion mechanisms . • Multiscale modeling deciphers inhibition mechanisms through DFT/MC/MD. The depletion of fossil fuel reserves and their environmental impact have driven the adoption of ethanol-gasoline blends (EGBs) as an alternative fuel, with the aim of reducing gasoline consumption and greenhouse gas emissions. However, the introduction of water and pollutant ions during bioethanol production, transportation, and usage has the potential to lead to corrosion in pipelines and storage equipment. This study investigates the corrosion behaviour of T2 copper in EGBs containing a simulated liquid (SL) and evaluates the corrosion inhibition mechanism of Turkish red oil (TRO) as an eco-friendly inhibitor. Surface observation, electrochemical techniques, and surface analysis (SEM, AFM , XPS) were employed to assess corrosion behaviour. The results obtained from this study indicate that an increase in SL concentration results in an intensification of corrosion, as evidenced by a decrease in charge transfer resistance ( R ct ) and an increase in corrosion current density ( I corr ). The addition of TRO has been shown to significantly inhibit corrosion, with optimal efficiency exceeding 90 % at 500 ppm, resulting in a smooth copper surface. Furthermore, XPS analysis has confirmed the adsorption of TRO molecules on T2 copper, while theoretical analysis has revealed that TRO's electron-donating and electron-accepting groups facilitate parallel adsorption, thereby enhancing corrosion inhibition. This study provides experimental and theoretical insights into the corrosion inhibition of green organics in EGBs, supporting their wider application in sustainable energy systems.