Purification of motor fuels by means of extraction using deep eutectic solvent based on choline chloride and glycerol

BACKGROUND Deep eutectic solvents (DESs) are being used in different applications as replacements for classical organic solvents; their physico-chemical properties comply with the criteria of environmental acceptability. RESULTS In this work, choline chloride-glycerol based DESs of different molar ratios (ChCl-Gly 1:1.5, 1:2 and 1:3) were prepared and characterized with respect to density, dynamic viscosity, refractive index, electrical conductivity and thermal properties. The DESs were tested for denitrification, desulfurization and dearomatization of the six-component model gasoline composed of three aliphatic hydrocarbons and pyridine, thiophene and toluene as representatives of nitrogen, sulfur and aromatic compounds of fuel, respectively. It was found that ChCl-Gly is a better solvent for removal of pyridine from model gasoline in comparison with thiophene and toluene. Optimally, denitrification efficiency of 58% can be achieved in one-stage extraction, and deep denitrification can be achieved in five-stage extraction resulting in an efficiency of 99.62%. By performing a four-stage extraction using the same batch of DES, a gradual decrease in extraction efficiency was observed. By evaporative purification of DES between the stages, the extraction efficiency was found to remain constant. ChCl-Gly exhibited significant efficiency in denitrification of fluid catalytic cracking gasoline as well. CONCLUSION ChCl-Gly based DESs are suitable for denitrification of fuel. The ability of application environmentally friendly solvents in the fuel purification process contributes to the development of cleaner technologies. (c) 2018 Society of Chemical Industry