Deep desulfurization of fuels based on deep eutectic theory

In recent years, desulfurization of fuels has become a hot issue for the serious environmental pollution by organic sulfides. Compared with the traditional desulfurization process of fuels, this proposed process of deep desulfurization based on deep eutectic theory has many advantages, such as simple and environmental friendly process, cheap and easily obtained raw materials. In this study, series of alcohols have been designed and used to extract dibenzothiophene (DBT) from fuels. Moreover, some important factors that affect extraction process, such as alcohol type, phase ratio, extraction time, system temperature, stirring speed etc, were investigated in detail to optimize this specific desulfurization process. The result shows that polyethylene glycol (PEG-400) gets the highest desulfurization efficiency, which could reach as high as 99.9% in optimal conditions (25 degrees C, 30 min, phase ration 1:1). Finally, the extraction mechanism was probed with nuclear magnetic resonance hydrogen spectrum (H-1 NMR) and fourier-transform infrared spectroscopy (FT-IR). Through NMR and FT-IR, the hydrogen bond formed between active hydrogen of PEG and sulfur atom of DBT accounts for the higher extraction efficiency. This work will provide a new process for the deep desulfurization of fuels.