Eco-friendly oxidative desulfurization of model diesel fuel using glycerol-based deep eutectic solvents

Glycerol-based deep eutectic solvents were synthesized and applied as extractive solvents in oxidation desulfurization of model diesel. Ammonium chloride, triethylammonium acetate, and choline chloride were used as hydrogen bond acceptors of DESs. Molar ratios of HBA:HBD were taken 1:6. As the model fuel used n-decane and hexadecane. Sulfuric components of model diesel fuel were thiophene (5%) and dibenzothiophene (2%). Hydrogen peroxide (30%) was chosen as an oxidative agent of the oxidation desulfurization processes. Oxidation desulfurization processes were conducted in 1 and 3 hours of mixing at 60° and 90°C temperatures. The effects of reaction time, temperatures, the molar ratio of DES/model fuel, and the volume ratio of H2O2 were studied. Thiophene and dibenzothiophene showed better purification efficiencies at 90°C. Thiophene (5%) was completely separated from model fuel in 1 hour by NH4Cl/6Glycerol and ChCl/6Glycerol. [TEAH+][AcO-]/6Glycerol demonstrated the same result in 3 hours. The high desulfurization rate of dibenzothiophene was 95% by NH₄Cl/6Glycerol. All separation processes were controlled with the help of the NMR method.