Catalytic Oxidative-Extractive Deep Desulfurization of Diesel Fuel by N-methyl-2-pyrrolidone-Based Protic Acidic Ionic Liquids (PAILs)

Document Type : Research Article


1 Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186 Tehran, I.R. IRAN

2 Mazandaran University of Science and Technology, Babol, I.R. IRAN


Inexpensive and low-viscosity Protic Acidic Ionic Liquids (PAILs) of N-metheyl-2-pyrrolidone formate, acetate, and propionate abbreviated as [Hnmp][HCOO], [Hnmp][CH3COO] and [Hnmp][CH3CH2COO] respectively, were prepared and characterized by FT-IR and H-NMR. Deep oxidative and extractive desulfurization of a simulated oil and a real diesel containing 1000 ppmw sulfur were studied under the catalysis of the proposed PAILs without additional carboxylic acid and extraction solvent in the system. The desulfurization efficiency in this study was influenced by both amounts of PAILs and concentration of the produced peroxy acids from H2O2. Comparing to [Hnmp][HCOO], [Hnmp][CH3COO] and [Hnmp][CH3CH2COO] had a relatively higher extraction ability however the weaker acidic properties of them resulted in a lower activation of H2O2 to produce peroxy acids and finally led to lower oxidative desulfurization (ODS) efficiency in the same condition. Additionally, the neutralization reaction may not be efficiently gone to the right hand by weaker acids. The effects of the main process variables were studied in detail. The highest desulfurization yield of 97% for BT and 99% for DBT and 4,6-DMDBT, were achieved using [Hnmp][HCOO] in the ODS system at a temperature of 40 °C, H2O2/sulfur molar ratio of 10, VPAIL/Voil of 0.2, and a reaction time of 90 min. The immiscibility of the proposed PAILs in this study with the oil phase caused the easy separation of them after desulfurization. The possible ODS pathway was also proposed.


Main Subjects

[1] Yu G., Zhao J., Song D., Asumana C., Zhang X., and Chen X., Deep Oxidative Desulfurization of Diesel Fuels by Acidic Ionic Liquids, Ind. Eng. Chem. Res., 50: 11690–11697 (2011).
[2] Faghihian H., Naeemi S., Application of a Novel Nanocomposite for Desulfurization of a Typical Organo Sulfur Compound, Iran. J. Chem. Chem. Eng. (IJCCE), 32(3): 9-15 (2013).
[3] Azimzadeh H., Akbari A., Omidkhah M.R., Catalytic Oxidative Desulfurization Performance of Immobilized NMP.FeCl3 Ionic Liquid on g-Al2O3 Support, Chem. Eng. J., 320:  189–200 (2017).
[4] Akbari A., Omidkhah M.R., Towfighi Darian J., Facilitated and Selective Oxidation of Thiophenic Sulfur Compounds Using MoOx/Al2O3–H2O2 System under Ultrasonic Irradiation, Ultraso. Sonochem., 23: 231–237 (2015).
[6] Ali S.H., Hamad D.M., Albusairi B.H., Fahim M.A., Removal of Dibenzothiophenes from Fuels by Oxy-Desulfurization, Energy Fuels, 23: 5986–5994 (2009).
[7] Zhao D., Sun Z., Li F., Liu R., Shan H., Oxidative Desulfurization of Thiophene Catalyzed by (C4H9)4NBr.2C6H11NO Coordinated Ionic Liquid, Energy Fuels, 22: 3065 (2008).
[8] Li F., Liu R., Wen J., Zhao D., Sun Z., Liu Y., Desulfurization of Dibenzothiophene by Chemical Oxidation and Solvent Extraction with Me3NCH2C6H5Cl.2ZnCl2 Ionic Liquid, Green Chem., 11: 883-888 (2009).
 [9] Filippis P.D., Scarsella M., Verdone N., Oxidative Desulfurization I: Peroxyformic Acid Oxidation of Benzothiophene and Dibenzothiophene, Ind. Eng. Chem. Res., 49: 4594–4600 (2010).
[10] Akbari A., Omidkhah M.R., Towfighi Darian J., Optimization of Operating Conditions in Oxidation of Dibenzothiophene in the Light Hydrocarbon Model, Chem. Ind. Chem. Eng. Q., 20(3): 315-323 (2014).
[11] Otsuki S., Nonaka T., Takashima N., Qian W., Ishihara A., Imai T., Kabe T., Oxidative Desulfurization of Light Gas Oil and Vacuum Gas Oil by Oxidation and Solvent Extraction, Energy Fuels, 14: 1232–1239 (2000).
[12] Yu G., Li X., Liu X., Asumana C., Chen X., Deep Desulfurization of Fuel Oils Using Low-Viscosity 1-Ethyl-3-methylimidazolium Dicyanamide Ionic Liquid, Ind. Eng. Chem. Res., 50: 2236–2244 (2011).
[14] Bui T.T.L., Nguyen D.D., Ho S.V., Nguyen B.T., Uong H.T.N., Synthesis, Characterization and Application of Some Non-Halogen Ionic Liquids as Green Solvents for Deep Desulfurization of Diesel Oil, Fuel, 191: 54-61 (2017).
[15] Zhao D.S., Wang Y.N., Duan E.H., Oxidation Desulfurization of Fuel Using Pyridinium-Based Ionic liquids as Phase-Transfer Catalysts, Fuel Processing Technology, 91: 1803–1806 (2010).
[16] Li F., Wu B., Liu R., Wang X., Chen Zhao L., D., An Inexpensive N-Methyl-2-pyrrolidone-based Ionic Liquid as Efficient Extractant and Catalyst for Desulfurization of Dibenzothiophene, Chem. Eng. J., 274: 192-199 (2015).
[17] Liang W., Zhang S., Li H ., Zhang G., Oxidative Desulfurization of Simulated Gasoline Catalyzed by Acetic Acid-Based Ionic Liquids at Room Temperature, Fuel Processing Technology, 109: 27–31 (2013).
[18] Chen X., Guan Y., Abdeltawab A.A., Al-Deyab S.S., Yuan X., Wang C., Yu G., Using Functional Acidic Ionic Liquids as Both Extractant and Catalyst in Oxidative Desulfurization of Diesel Fuel: An Investigation of Real Feedstock, Fuel, 146: 6–12 (2015).
[19] Yang H., Jiang B., Sun Y., Hao L., Huang Z., Zhang L., Synthesis and Oxidative Desulfurization of Novel Lactam-Based Brønsted-Lewis Acidic Ionic Liquids, Chem. Eng. J., 306: 131-138 (2016).
[21] Li H., Zhu W., Wang Y., Zhang J., Lu J., Yan Y., Deep Oxidative Desulfurization of Fuels in Redox Ionic Liquids Based on Iron Chloride, Green Chem., 11: 810-815 (2009).
[22] Nie Y., Dong Y., Bai L., Dong H., Zhang X., Fast Oxidative Desulfurization of Fuel Oil Using Dialkylpyridinium Tetrachloroferrates Ionic Liquids, Fuel, 103: 997–1002 (2013).
[23] Zhu W., Wu P., Yang L., Chang Y., Chao Y., Li H., Jiang Y., Jiang W., Xun S., Pyridinium-Based Temperature-Responsive Magnetic Ionic Liquid for Oxidative Desulfurization of Fuels, Chem. Eng. J., 229: 250-256 (2013).
[24] Zhang L., Wang J., Sun Y., Jiang B., Yang H., Deep Oxidative Desulfurization of Fuels by Superbase-Derived Lewis Acidic Ionic Liquids, Chem. Eng. J,. 328: 445–453 (2017).
[25] Gao S., Li J., Chen X., Abdeltawab A.A., Yakout S.M., Yu G., A Combination Desulfurization Method for Diesel Fuel: Oxidation by Ionic Liquid with Extraction by Solvent, Fuel, 224: 545–551 (2018).
[27] Jiang W., Dong L., Li H., Jia H., Zhu L., Zhu W., Li H., Magnetic Supported Ionic Liquid Catalysts with Tunable Pore Volume for Enhanced Deep Oxidative Desulfurization, J. Molec. Liq., 274: 293-299 (2019).
[28] Chen X., Zhang M., Wei Y., Li H., Liu J., Zhang Q., Zhu W., Li H., Ionic Liquid-Supported 3DOM Silica for Efficient Heterogeneous Oxidative Desulfurization, Inorg. Chem. Front., 5: 2478-2485 (2018).
[29] Olivier-Bourbigou H., Magna L., Morvan D., Ionic Liquids and Catalysis: Recent Progress from Knowledge to Applications, Appl. Catal. A General, 373: 1-56 (2010).
[30] Anouti M., Caillon-Caravanier M., Dridi Y., Galiano H., Lemordant D., Synthesis and Characterization of New Pyrrolidinium Based Protic Ionic Liquids, Good and Superionic Liquids, J. Phys. Chem. B, 112: 13335-13343 (2008).
[31] Amarasekara A.S., Acidic Ionic Liquids, Chem. Rev., 116 (10): 6133-6183 (2016).
[32] Wang H. Lu, S., Deng C., Ren W., Guo B., Oxidative Desulfurization of Model Diesel via Dual Activation by a Protic Ionic Liquid, J. Hazard. Mater., 279: 220-225 (2014).
[33] Zhang B., Jiang Z., Li J., Zhang Y., Lin F., Liu Y., Li C., Catalytic Oxidation of Thiophene and Its Derivatives via Dual Activation for Ultra-Deep Desulfurization of Fuels, J. Catalysis, 287: 5-12 (2012).