Selective Extraction and Identification of Neutral Nitrogen Compounds Contained in Straight-Run Diesel Feed Using Chloride Based Ionic Liquid

Abstract

Extraction of neutral nitrogen-containing compounds (N-compounds) has been investigated with chloride based ionic liquids (ILs) with varying cation classes (imidazolium, pyridinium). ILs were first discriminated by their mutual solubility of ILs and model fuel. Low solubility of 1-butyl-3-methylimidazolinium chloride (BMImCl) and 1-octylpyridinium chloride (OcPyCl) in the model fuel was observed. The ILs were then evaluated using a synthetic solution with dibenzothiophene and carbazole as model compounds, and a high selectivity for N-compounds was found. BMImCl and OcPyCl were then evaluated using straight-run diesel feed, containing 13 400 ppm S and 105 ppm N. An extraction of up to 50% of the N-compounds was obtained in one step whereas the sulfur concentration reduction was only 5%. Both ILs can be regenerated using small amount of water. Extracted compounds could be then extracted using toluene. The major constituents were identified by GC-MS. Analysis of the extracted compounds emphasized the selectivity of the extraction process. Furthermore, refractory sulfur-containing compounds (S-compounds) and polyaromatics were also identified in the extract.

Aromatic sulfur‐nitrogen extraction using ionic liquids: Experiments and predictions using an a priori model

“…6 Liquid-liquid extraction (LLE) is an efficient process as compared to distillation, absorption, and other chemical process for the removal of aromatic sulfur and nitrogen containing compounds from diesel oil. [12][13][14] The main advantages of LLE as compared to other separation processes are ambient temperature and atmospheric pressure, 15 no additional catalyst, 15,16 and low energy consumption. 2 In addition, the hydrogen consumption and handling are also eliminated.…”

Removal of Basic Nitrogen Compounds from Fuel Oil with [Hnmp]H2PO4 Ionic Liquid

“…For example, imidazolium-based ILs with HSO 4 -anion or H 2 PO 4 -anion 9-11 achieved very high basic N-extraction efficiency of more than 90 %. Charles et al 12 found that ILs with N(CN) 2 anion exhibited a better extraction effect for non-basic N-compounds than for basic N-compounds, e.g., the extraction efficiency of carbazole can reach 100 % with [BMI] 14,15 has a very highly selective extraction for neutral N-compounds in the diesel oil, while a further study 16 found that the ionic liquid can remove 55 % of nitrogen from straight run gas oil containing 0.0105 w% nitrogen. Gabric et al 17 selected five imidazolium-based ILs to extract thiophene, dibenzothiophene and pyridine from two model solutions, and found the extraction efficiency of pyridine was almost twice higher than that observed for thiophene and dibenzothiophene.…”

Efficient concurrent removal of sulfur and nitrogen contents from complex oil mixtures by using polyoxometalate-based composite materials

“…Recently, they have also been widely applied to remove sulfur compounds from fuels through an extraction process. [21][22][23] However, ILs exhibit a limited sulfur extraction ability which can reach a value of ~12-30 %. 24 Interestingly, Zhang et al 25 reported a promising simultaneous extraction and catalytic oxidative desulfurization and denitrogenation system using a functionalized ionic liquid component in a IL/M n Xn (where M: Fe, Zn and n = 2 or 3) system in the presence of a rather simpler oil mixture of two sulfur (100 ppm) and nitrogen (500 ppm) containing substrates.…”