Corrosion Of Steel In 1-butyl-3-methylimidazolium Hydrogen Sulfate Ionic Liquid Systems For Desulfurization Application

1-butyl-3-methylimidazolium hydrogen sulfate([BMIM]HSO4)ionic liquid(IL)has been proved is an ideal candidate for deep desulfurization of fuel oils,but the corrosion behavior of[BMIM]HSO4 for desulfurization application have not been studied.Since the IL-based desulfurization systems containing model oil,water and hydrogen peroxide,its corrosion properties is different from pure IL,so the investigations of corrosion characteristics of IL-based desulfurization systems are urgently needed.The corrosion behavior of two typical metals,namely mild steel and stainless steel,in IL systems for desulfurization application were investigated by IR spectra,Raman spectra,weight loss measurements,electrochemical tests and SEM.The results showed that stainless steel had better resistance than mild steel in all systems.The adsorption of IL molecules on steel surface was confirmed by IR spectra.SEM results indicated that severe localized corrosion was attributed to the presence of water and hydrogen peroxide.The side effect of corrosion on the IL-based desulfurization process was also studied.The distribution of HOMO and LUMO,Fukui indices and quantum parameters on IL molecule were calculated by quantum chemical calculation.The results show that the imidazolium ring and hydrogen sulfate play the most important role in the interaction between IL and metal surface.The quantum parameters of IL in aqueous solution significantly change and chemical adsorption ability becomes weak.The adsorption process and adsorption energy of IL on steel surface in water-free and aqueous environments are investigated by molecular dynamics simulation.