Nie Yi

Simultaneous desulfurization and denitrogen of liquid fuels using two functionalized group ionic liquids

Deep desulfurization of liquid fuels is an important and challenging issue in worldwide petroleum refining industry. Extraction and catalytic oxidative desulfurization (ECODS) of liquid fuels using a series of ionic liquids (ILs) with two functionalized groups, such as [(CH2)2COOHmim]Cl/nFeCl3, [(CH2)2COOHmim]Cl/nZnCl2, and [Amim]Cl/nFeCl3, was studied. In the ECODS, the ILs were used as both extractant and catalyst and 30 wt% hydrogen peroxide (H2O2) solution as oxidant. The effects of molar ratios of [(CH2)2COOHmim]Cl (or [Amim]Cl) to FeCl3 (or ZnCl2) in ILs, H2O2/sulfur (O/S) molar ratio, reaction temperature, and the nature of sulfur compounds on sulfur removal were investigated. The natures of the functional groups (-COOH, -CH2-CH=CH2) in cations and the acid strength of anions play important roles in the ECODS and affect the reaction time, temperature, and desulfurization efficiency of different substrates. Also, nitrogen-containing compounds (pyridine, pyrrole, and quinoline) could be removed simultaneously in the ECODS and had different effects on dibenzothiophene removal.

Study on the recovery of ionic liquids from dilute effluent by electrodialysis method and the fouling of cation-exchange membrane

With the wide application of ionic liquids (ILs) in various fields, developing efficient techniques to recover ILs from effluent is an urgent demand for the cost reduction and the environmental protection. In this study, an electrodialysis (ED) method was used to recover 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) IL from aqueous solution as model effluent. The influences of initial IL concentration and applied voltage on the current efficiency, removal ratio, desalination ratio, membrane flux and specific energy consumption during the ED process were investigated. It was found that the removal ratio and desalination ratio increases with the increasing of initial IL concentration and applied voltage. The current efficiency decreases with the increasing of initial IL concentration and the current efficiency reached the maximum value of 94.3% at 25 V. Besides, as the applied voltage increases, the membrane flux increases and the specific energy consumption decreases. Moreover, the fouling of cation-exchange membrane was also discovered after the desalination of IL. The deposits on the surface or into the membrane which is probably caused by [Bmim]+ was characterized by scanning electron microscopy, elemental analysis and Fourier transform infrared.

Extraction of coal-tar pitch using NMP/ILs mixed solvents

Coal-tar pitch (CP) is a promising carbon raw material for producing needle coke, carbon fiber etc. During processing, the H/C ratio, ash content, and quinoline insoluble (QI) in the CP are the key factors that influence the material preparation. In this study, NMP was selected to extract CP first; then [BMIM]Cl/NMP mixed solvent was used; and finally a series of ionic liquids (ILs) mixtures with NMP were developed for the extraction of CP to obtain the refined pitch. The extracts were analyzed via elemental analysis, TGA, FT-IR, and 13C-NMR. Results indicate that different NMP/IL mass ratios or different kinds of ILs have impact on the extraction yield. The relationship of the hydrogen to carbon (H/C) ratio changed with different solvents and QI extracts were obtained. Results showed that the H/C ratios changed little between NMP extracts and could be adjusted by changing the NMP/ILs mass ratio or using different ILs. The extracts are suitable for preparation mesophase pitch because of no ash content, low QI, and appropriate H/C ratios. As a result, NMP can be used to refine pitch. In addition, [BMIM]Cl is good mixed with NMP for CP extraction, because it can obtain a relatively high yield under the same extraction conditions.