(512f) Oil Desulfuriztion Using Deep Eutectic Solvents Via Liquid-Liquid Extraction

Catalytic hydrodesulfurization is the common process that is used in the industry to achieve low sulfur concentrations in oil fuels [1]. However, it is usually conducted at relatively high pressure and temperature that results in an expensive and energy intensive process. In this paper, two deep eutectic solvents (DESs) were evaluated for their extraction properties of sulfur derivatives from two aliphatic hydrocarbons via liquid-liquid extraction. The mixtures thiophene/n-hexane and thiophene/n-octane were selected as oil models. The selected DESs were (i) tetrahexylammonium bromide:ethylene glycol with molar ratio = 1:2 (DES 1) and (ii) tetrahexylammonium bromide:glycerol with molar ratio = 1:2 (DES 2). To confirm the suitability of the DESs for the system {aliphatic+thiophene+DES}, the binary solubility of thiophene/DES and aliphatic/DES was tested at T/K = 298 and atmospheric pressure. Then, the liquid−liquid equilibrium (LLE) data of the ternary systems {n-hexane + thiophene + DES 1}, {n-hexane + thiophene + DES 2}, {n-octane + thiophene + DES 1} and }n-octane + thiophene + DES 2} were determined at T/K = 298 and atmospheric pressure. Also, the solute distribution ratios and the selectivities were calculated from the experimental LLE data and compared to the literature. Moreover, the DES were successfully regenerated by means of vaccum evaporation. Finally, the experimental LLE data were correlated using the nonrandom two-liquid (NRTL) thermodynamic model. It was found that the DESs are potential solvents for desulfurization procesess.

References

[1] S. Brunet, D. Mey, G. Perot, C. Bouchy, and F. Diehl, “On the hydrodesulfurization of FCC gasoline: A review,” Appl. Catal. A Gen., vol. 278, no. 2, pp. 143–172, 2005.