Extraction of bicyclic S/N-compounds from FCC diesel with ionic liquid: experimental and molecular insight

doi:10.11949/0438-1157.20240370

Abstract

Abstract:

Extraction technology can be considered as an important supplement to the hydrodesulfurization and denitrification process to separate aromatic sulfur and nitrogen components in oil products. This study investigates the separation of benzothiophene and quinoline from fuel oils using ionic liquids (IL) as extractive solvent at both molecular and experimental scales. COSMO-RS model identified 1-ethyl-3-methylimidazolium dicyandiamide ([EMIM][DCA]) as the optimal IL extractant from 37 IL candidates. The extraction performance of [EMIM][DCA] for separating benzothiophene and quinoline was demonstrated by liquid-liquid equilibrium experiments. Regeneration experiment indicates that the selected IL maintained stable extraction efficiency in 5 cycles. The separation mechanism of the extraction process was uncovered. Molecular dynamic simulations and quantum chemical calculations show that π-π interactions and C—H…N hydrogen bonding between the IL and benzothiophene/quinoline are the primary forces driving the efficient separation. The conclusions present here offer theoretical guidance for designing new and effective extractants.

Key words: extraction desulfurization and denitrification, ionic liquid, phase equilibrium, molecular simulation, quantum chemical calculation, COSMO-RS model

摘要：

萃取技术可以作为加氢脱硫脱氮工艺的重要补充用于分离油品中芳香性硫氮组分。在分子尺度和实验尺度对离子液体萃取分离苯并噻吩和喹啉进行探讨，利用COSMO-RS模型从37种常见离子液体中确定1-乙基-3-甲基咪唑双氰胺盐（[EMIM][DCA]）为最佳离子液体萃取剂。通过液液相平衡实验证明了[EMIM][DCA]萃取分离苯并噻吩和喹啉的可行性，再生实验表明所选离子液体在5次循环中萃取性能始终保持稳定。在分子尺度揭示了萃取过程的分离机理，分子动力学模拟和量子化学计算结果表明离子液体与苯并噻吩/喹啉之间形成的π-π相互作用和C—H…N氢键相互作用是离子液体高效分离苯并噻吩和喹啉的主要作用力。研究结果可为新型高效萃取剂设计提供理论指导。

关键词: 萃取脱硫脱氮, 离子液体, 相平衡, 分子模拟, 量子化学计算, COSMO-RS模型

CLC Number:

TQ 028.3

Siqi JIANG, Yufeng HU, Yongqiang CHENG, Qinghua LIU, Zhigang LEI. Extraction of bicyclic S/N-compounds from FCC diesel with ionic liquid: experimental and molecular insight[J]. CIESC Journal, 2024, 75(10): 3651-3659.

蒋斯麒, 胡玉峰, 程永强, 刘清华, 雷志刚. 离子液体萃取分离FCC柴油中双环芳香性硫氮组分：实验和分子机理[J]. 化工学报, 2024, 75(10): 3651-3659.

Figures/Tables 10

Table 1 LLE data for benzothiophene and quinoline systems

Upper phase			Lower phase
$w_{1}^{Ⅰ}$	$w_{2}^{Ⅰ}$	$w_{3}^{Ⅰ}$	$w_{1}^{Ⅱ}$	$w_{2}^{Ⅱ}$	$w_{3}^{Ⅱ}$
benzothiophene (1) + dodecane (2) + [EMIM][DCA] at 303.15 K with solvent ratio 1∶1
0.0376	0.9624	0	0.0241	0.0015	0.9744
0.0593	0.9407	0	0.0394	0.0023	0.9583
0.0886	0.9114	0	0.0726	0.0028	0.9246
0.1146	0.8854	0	0.0971	0.0036	0.8993
0.1352	0.8648	0	0.1225	0.0047	0.8728
0.1617	0.8383	0	0.1445	0.0053	0.8502
0.1852	0.8148	0	0.1619	0.0065	0.8316
0.2204	0.7796	0	0.1900	0.0074	0.8026
quinoline (1) + dodecane (2) + [EMIM][DCA] at 303.15 K with solvent ratio 1∶1
0.0192	0.9808	0	0.0321	0.0022	0.9657
0.0311	0.9689	0	0.0657	0.0027	0.9316
0.0524	0.9476	0	0.0941	0.0037	0.9022
0.0653	0.9347	0	0.1259	0.0048	0.8693
0.0782	0.9218	0	0.1547	0.0051	0.8402
0.0916	0.9084	0	0.1822	0.0062	0.8116
0.1106	0.8894	0	0.2081	0.0071	0.7848
0.1257	0.8743	0	0.2334	0.0083	0.7583

Table 1 LLE data for benzothiophene and quinoline systems

Upper phase			Lower phase
$w_{1}^{Ⅰ}$	$w_{2}^{Ⅰ}$	$w_{3}^{Ⅰ}$	$w_{1}^{Ⅱ}$	$w_{2}^{Ⅱ}$	$w_{3}^{Ⅱ}$
benzothiophene (1) + dodecane (2) + [EMIM][DCA] at 303.15 K with solvent ratio 1∶1
0.0376	0.9624	0	0.0241	0.0015	0.9744
0.0593	0.9407	0	0.0394	0.0023	0.9583
0.0886	0.9114	0	0.0726	0.0028	0.9246
0.1146	0.8854	0	0.0971	0.0036	0.8993
0.1352	0.8648	0	0.1225	0.0047	0.8728
0.1617	0.8383	0	0.1445	0.0053	0.8502
0.1852	0.8148	0	0.1619	0.0065	0.8316
0.2204	0.7796	0	0.1900	0.0074	0.8026
quinoline (1) + dodecane (2) + [EMIM][DCA] at 303.15 K with solvent ratio 1∶1
0.0192	0.9808	0	0.0321	0.0022	0.9657
0.0311	0.9689	0	0.0657	0.0027	0.9316
0.0524	0.9476	0	0.0941	0.0037	0.9022
0.0653	0.9347	0	0.1259	0.0048	0.8693
0.0782	0.9218	0	0.1547	0.0051	0.8402
0.0916	0.9084	0	0.1822	0.0062	0.8116
0.1106	0.8894	0	0.2081	0.0071	0.7848
0.1257	0.8743	0	0.2334	0.0083	0.7583

Fig.1 Solvent capacity and selectivity of 37 ionic liquids for benzothiophene/quinoline

Fig.2 Ternary diagram for benzothiophene system (a) and quinoline system (b) at 303.15 K and 105 Pa

Fig.3 Distribution coefficient (a) and selectivity (b) of [EMIM][DCA] for benzothiophene and quinoline

Fig.4 Extraction efficiency of [EMIM][DCA] for benzothiophene and quinoline in 5 cyclics

Fig.5 Density distribution of benzothiophene/quinoline and dodecane in Z-axis

Table 2 Interaction energy and energy decomposition results of optimized binary complex

No.	Binary complex	ΔE_total/(kJ/mol)	Energy/(kJ/mol)
No.	Binary complex	ΔE_total/(kJ/mol)	E_elst	E_disp	E_ind	E_exch
1	EMIM-BT	-56.14	-47.44	-61.76	-18.85	71.92
2	EMIM-QL	-67.90	-61.55	-54.72	-22.35	70.73
3	DCA-BT	-35.76	-31.96	-15.92	-19.15	31.27
4	DCA-QL	-46.56	-43.46	-17.47	-21.16	35.53
5	C12-BT	-27.57	-24.62	-61.15	-5.83	64.03
6	C12-QL	-28.69	-25.09	-63.35	-5.99	65.74

Fig.6 Angular and distance distributions between [EMIM]+ and benzothiophene (a) and quinoline (b)

Fig.7 IGM isosurface between different molecular segments

Fig.8 Electrostatic potential [(a)—(c)] and vdW potential [(d)—(f)] surface for studied moleculars

References 31

1	潘红蕊, 王媛媛. 油品脱氮技术研究进展[J]. 石化技术, 2021, 28(8): 77-78.
	Pan H R, Wang Y Y. Advances in denitrogenation technology of oil[J]. Petrochemical Industry Technology, 2021, 28(8): 77-78.
2	石亚华. 石油加工过程中的脱硫[M]. 北京: 中国石化出版社, 2009.
	Shi Y H. Desulfurization in Petroleum Processing[M]. Beijing: China Petrochemical Press, 2009.
3	宋红艳, 何静, 李春喜. 燃料油深度脱硫的技术策略及研究进展[J]. 石油化工, 2015, 44(3): 279-286.
	Song H Y, He J, Li C X. Technical strategies and recent advances for deep desulfurization of fuel oils[J]. Petrochemical Technology, 2015, 44(3): 279-286.
4	Bello S S, Wang C, Zhang M J, et al. A review on the reaction mechanism of hydrodesulfurization and hydrodenitrogenation in heavy oil upgrading[J]. Energy & Fuels, 2021, 35(14): 10998-11016.
5	Kulkarni P S, Afonso C A M. Deep desulfurization of diesel fuel using ionic liquids: current status and future challenges[J]. Green Chemistry, 2010, 12(7): 1139-1149.
6	Li A, Song H Y, Meng H, et al. Steric effects of alkyl dibenzothiophenes: the root cause of frustrating efficacy of heterogeneous desulfurization for real diesel[J]. AIChE Journal, 2022, 68(5): e17614.
7	Li G X, Gao Q H, Liu Q H, et al. Extraction of polycyclic aromatic hydrocarbons from fluid catalytic cracking diesel with ionic liquids[J]. AIChE Journal, 2023, 69(2): e17914.
8	Shin J, Oh Y, Choi Y, et al. Design of selective hydrocracking catalysts for BTX production from diesel-boiling-range polycyclic aromatic hydrocarbons[J]. Applied Catalysis A: General, 2017, 547: 12-21.
9	方静, 张淑婷, 李婷婷, 等. 离子液体用于燃油萃取脱硫的选择与过程优化[J]. 化工学报, 2017, 68(9): 3434-3441.
	Fang J, Zhang S T, Li T T, et al. Selection and process optimization of ionic liquids for desulfurization[J]. CIESC Journal, 2017, 68(9): 3434-3441.
10	Peng D L, Kleiweg A J, Winkelman J G M, et al. A hierarchical hybrid method for screening ionic liquid solvents for extractions exemplified by the extractive desulfurization process[J]. ACS Sustainable Chemistry & Engineering, 2021, 9(7): 2705-2716.
11	Wang D, Zhang T, Yang L, et al. Molecular mechanism and extraction explorations for separation of pyridine from coal pyrolysis model mixture using protic ionic liquid [Hnmp][HSO₄][J]. Fuel, 2022, 309: 122130.
12	Wang H, Xie C X, Yu S T, et al. Denitrification of simulated oil by extraction with H 2 P O 4 - based ionic liquids[J]. Chemical Engineering Journal, 2014, 237: 286-290.
13	Paucar N E, Kiggins P, Blad B, et al. Ionic liquids for the removal of sulfur and nitrogen compounds in fuels: a review[J]. Environmental Chemistry Letters, 2021, 19(2): 1205-1228.
14	Dong K, Liu X M, Dong H F, et al. Multiscale studies on ionic liquids[J]. Chemical Reviews, 2017, 117(10): 6636-6695.
15	Lei Z G, Dai C N, Chen B H. Gas solubility in ionic liquids[J]. Chemical Reviews, 2014, 114(2): 1289-1326.
16	Pena-Pereira F, Namieśnik J. Ionic liquids and deep eutectic mixtures: sustainable solvents for extraction processes[J]. ChemSusChem, 2014, 7(7): 1784-1800.
17	Bösmann A, Datsevich L, Jess A, et al. Deep desulfurization of diesel fuel by extraction with ionic liquids[J]. Chemical Communications, 2001(23): 2494-2495.
18	Selvan M S, McKinley M D, Dubois R H, et al. Liquid-liquid equilibria for toluene + heptane + 1-ethyl-3-methylimidazolium triiodide and toluene + heptane + 1-butyl-3-methylimidazolium triiodide[J]. Journal of Chemical & Engineering Data, 2000, 45(5): 841-845.
19	Song Z, Zhou T, Zhang J N, et al. Screening of ionic liquids for solvent-sensitive extraction—with deep desulfurization as an example[J]. Chemical Engineering Science, 2015, 129: 69-77.
20	惠燕华, 王辉, 刘福胜, 等. 三乙烯二胺类离子液体的合成及其用于脱除非碱性氮[J]. 石油化工, 2021, 50(2): 123-129.
	Hui Y H, Wang H, Liu F S, et al. Synthesis of triethylenediamine ionic liquids and their use in removing non-basic nitrogen[J]. Petrochemical Technology, 2021, 50(2): 123-129.
21	Zhang C L, Wu J, Wang R X, et al. Study of the toluene absorption capacity and mechanism of ionic liquids using COSMO-RS prediction and experimental verification[J]. Green Energy & Environment, 2021, 6(3): 339-349.
22	Klamt A, Eckert F. COSMO-RS: a novel and efficient method for the a priori prediction of thermophysical data of liquids[J]. Fluid Phase Equilibria, 2000, 172(1): 43-72.
23	Klamt A, Eckert F, Arlt W. COSMO-RS: an alternative to simulation for calculating thermodynamic properties of liquid mixtures[J]. Annual Review of Chemical and Biomolecular Engineering, 2010, 1: 101-122.
24	Kurczab R, Mitoraj M P, Michalak A, et al. Theoretical analysis of the resonance assisted hydrogen bond based on the combined extended transition state method and natural orbitals for chemical valence scheme[J]. The Journal of Physical Chemistry A, 2010, 114(33): 8581-8590.
25	Sprenger K G, Jaeger V W, Pfaendtner J. The general AMBER force field (GAFF) can accurately predict thermodynamic and transport properties of many ionic liquids[J]. The Journal of Physical Chemistry B, 2015, 119(18): 5882-5895.
26	Yoshida Y, Baba O, Saito G. Ionic liquids based on dicyanamide anion: influence of structural variations in cationic structures on ionic conductivity[J]. The Journal of Physical Chemistry B, 2007, 111(18): 4742-4749.
27	Crosthwaite J M, Muldoon M J, Dixon J K, et al. Phase transition and decomposition temperatures, heat capacities and viscosities of pyridinium ionic liquids. [J]. J. Chem. Thermodyn., 2005, 37(6): 559-568.
28	Nishida T, Tashiro Y, Yamamoto M. Physical and electrochemical properties of 1-alkyl-3-methylimidazolium tetrafluoroborate for electrolyte[J]. J. Fluorine. Chem., 2003, 120(2): 135-141.
29	Fan W Y, Huang H W, Li Q, et al. Liquid-liquid equilibria for separation of benzothiophene from model fuel oil: solvent screening and thermodynamic modeling[J]. The Journal of Chemical Thermodynamics, 2022, 167: 106693.
30	Lu T, Chen F W. Multiwfn: a multifunctional wavefunction analyzer[J]. Journal of Computational Chemistry, 2012, 33(5): 580-592.
31	Humphrey W, Dalke A, Schulten K. VMD: visual molecular dynamics[J]. J. Mol. Graph., 1956, 14(1): 33-38.

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