Extraction mechanism of cerium(Ⅳ) in H_2SO_4/H_3PO_4 system using bifunctional ionic liquid extractants

The extraction of Ce（Ⅳ） in H2SO4/H3PO4 system was investigated systematically using bifunctional ionic liquid extractants（Bif-ILES） [A336][P507],[A336][P204] and [A336][C272] in n-heptane.The effects of H2SO4 concentration,extractant concentration and salting-out agent concentration were observed in detail.The extraction mechanism of Ce（Ⅳ） in H2SO4/H3PO4 system was obtained.The comparison with other extractants such as Cyanex923,TBP was also studied.Thermodynamic functions of the extraction reaction were calculated,showing that the extraction was an exothermic process.The separation of Ce（Ⅳ） from RE（Ⅲ） and Th（Ⅳ） was also investigated.The result indicated that Ce（Ⅳ） could be selectively extracted in this system.CePO4 nanoparticles were obtained in the process of stripping using H2O2 in H2SO4/H3PO4 system.X-ray diffraction（XRD）,scanning electron microscopy（SEM） and spectroscopy were adopted for the characterization of the sample.

Design, Optimization and Control of Extractive Distillation for Separation of Ethyl Acetate-Ethanol-Water Mixture Using Ionic Liquids

In this work, the process simulation of pressure-swing distillation(PSD) and extractive distillation(ED) using ionic liquid(IL) 1-butyl-3-methylimidazolium acetate([bmim][OAc]) as the entrainer for separation of ethyl acetateethanol-water mixture is performed. The design parameters of the two distillation processes are optimized with the minimum total annual cost(TAC) serving as the objective function. The results show that the TAC saving of ED process is 35.27% in comparison with that of PSD process in the case of achieving the same purity and yield of ethyl acetate.In addition, the dynamic controllability of ED process is further studied. The traditional two-point temperature control structure is proposed for the ED process, and it works pretty well while taking into account the disturbances in both feed rate and feed composition.

Simulation for Transesterification of Methyl Acetate and n-Butanol in a Reactive and Extractive Distillation Column Using Ionic Liquids as Entrainer and Catalyst

有 entrainer 和催化剂(RED-IL ) 被建议与 n-butanol 由甲基醋酸盐的 transesterification 反应生产甲醇和 n 丁基醋酸盐的离子的液体的一个新反应、引得出的蒸馏过程。RED-IL 过程经由一个严密模型，和甲醇的高纯净产品被模仿， n 丁基醋酸盐能在如此的一个过程被获得。倒流比率的效果，喂模式，劫盗，喂地点， entrainer 比率和催化剂 RED-IL 过程上的集中被调查。甲基醋酸盐的变换和有在列， entrainer 比率和催化剂内容的劫盗的产品增加的纯净。最佳的倒流比率在 RED-IL 过程存在。比作混合喂模式，分离喂模式是更有效的，在哪个最佳喂反应物的地点存在。

Preparation of REPO_4(RE=La–Gd) nanorods from an ionic liquid extraction system and luminescent properties of CePO_4:Tb^(3+)

Uniform nanorods of rare earth phosphate(REPO_4, RE = La–Gd) nanocrystals were prepared in a properly designed ionic liquid extraction system by a stripping precipitation method. Rare earth ions were extracted into the organic phase at first; after that, the loaded organic phase was stripped by aqueous solution of PO_4^(3-) under stirring at room temperature within 5 min.The extractant used here is a bifunctional ionic liquid extractant called [A336][cyanex272]. The products are hexagonal phase in crystal structure, and their morphology is nanorods. The diameter of the products is from 30 to 50 nm, and the length increases from 200 nm to 2 μm gradually. Besides, the ionic liquid-absorbed CePO_4:Tb^(3+) nanorods show improved luminescent emitting intensity and lifetime. Based on the results, a possible growth mechanism of the REPO_4(RE = La–Gd) nanorods is proposed, where the extractants here also play roles of structure-directing agents and surfactants during the formation process of nanocrystals.

Deep Extractive Desulfurization of Gasoline with Ionic Liquids Based on Metal Halide

Ionic liquid [Et3NH]Cl-FeCl3/CuCl was synthesized by mixing [Et3NH]Cl, anhydrous FeCl3 and anhydrous CuCl, and the desulfurization activity of this ionic liquid was tested. It exhibited remarkable ability in effective desulfurization of model gasoline(thiophene in n-octane) and fluid catalytic cracking(FCC) gasoline, and the sulfur removal of thiophene in model oil(V(IL):V(oil)=0.08) could reach 93.9% in 50 min at 50 ℃. Low-sulfur(﹤10 μg/g) FCC gasoline could be obtained after three extraction runs at an ionic liquid/oil volume ratio of 0.1, with the yield of FCC gasoline reaching 94.3%. The ionic liquid could be recycled 5 times with merely a slight decrease in activity.

Use of Ionic Liquid-filled Semipermeable Membrane for Extraction of Polycyclic Aromatic Hydrocarbons in Water

A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3- methylimidazolium hexafluorophosphate ([C4MIM][PF6]) – filled semipermeable membrane. For 24 hrs extraction of naphthalene, 1-methylnaphthalene, 2-chloronaphthalene, phenanthrene, the result showed that the extraction efficiency, correlation coefficient (R2) and RSD (n=5) were in the range of 67-102 %, 0.9870-0.9962, and 2.1-5.3 %, respectively.

Efficient Extraction of Agarose from Red Algae Using Ionic Liquids

We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventional methods, a very high extraction yield of good quality agarose (as high as 39 wt%) could be achieved depending upon the nature of used IL and applied experimental conditions. Purity of extracted agarose was confirmed from various spectral and analytical techniques, such as 1H and 13C NMR, FTIR, circular dichroism (CD), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The physicochemical properties, such as gelling or melting temperature, viscosity and gel strength of extracted agarose hydrogels have been measured and compared with the agarose obtained from similar source reported in the literature. ILs were recovered after the extraction of agarose and were reused for further extraction experiments. % Recycling and extraction ability of recycled ILs in different cycles have been measured. The developed extraction process of utilizing ILs as medium is easy, simple and highly efficient as compared to the conventional methods of agarose extraction from algae.

Extraction of lanthanides from nitric acid solution using isobutyl-BTP/ionic liquid system

Extraction behavior of lanthanides(La, Eu, Dy, Lu) from HNO3 solution was studied using a novel extraction system with hydrophobic ionic liquid being diluent and isobutyl-BTP being extractant. Compared with that in isobutyl-BTP/cyclohexane extraction system, application of ionic liquid as the extracting phase provided unprecedented enhancement of the extraction performance of isobutyl-BTP for lanthanides. It was found that the isobutyl-BTP/[Cnmim][NTf2] extraction system is favorable to get good extraction at low acidity condition(< 0.1 M). Of all the isobutyl-BTP/ [C n mim][NTf2](n = 2, 6, 8) systems, isobutyl-BTP/[C2mim][NTf2]extraction system provides the best extraction performance and fastest extraction kinetics within 5 min towards Dy3+. The extraction is spontaneous endothermic and temperature is good for extraction. The transfer of lanthanides, in isobutyl-BTP/[C2mim][NTf2] extraction system, proceeded via a cation exchange mechanism, in contrast to extraction of neutral complex in the cyclohexane system.

Adsorption by Liquid-Liquid Extraction of Hg(II) from Aqueous Solutions Using the 2-Butyl-imidazolium Di-(2-ethylhexyl) Phosphate as Ionic Liquid

In this work, a novel room temperature ionic liquid (2-butyl-imidazolium di-(2-ethylhexyl) phosphate) ([C4mim] [D2EHPA]) was synthesized and tested as extractant in the mercury(II) liquid-liquid extraction. The effects of parameters such as aqueous to organic phase’s volume ratio, metal concentration IL concentration, pH levels, ionic strength, and temperature were reported. For the extraction of metal, [C4mim]3[R.HR]3[HgCl2]org and [C4mim]3[R.HR]3 [HgClOH]org species were formed where (H2R2) was D2EHPA. In the case of ionic strength, the results showed that the addition of sodium acetate at 0.302 mmol·L?1 to the aqueous phase strongly increased the mercury extraction yield (R = 100%). The extracted species were investigated by a calculation program using CHEAQS V. L20.1 inorder to determine the relation between the percentages of the extracted species and the extraction yield. The results showed that the extracted species in the best conditions were HgCl2 and HgClOH with respective percentages 80.66% and 18.29%.

Cu(II) Extraction in Ionic Liquids and Chlorinated Solvents: Temperature Effect

Room temperature ionic liquids have been currently used in liquid/liquid extraction processes in order to substitute conventional organic solvents. In this paper, a series of chlorinated solvents and 1-alkyl-3-me- thylimidazolium-based ionic liquids were selected to study the extraction efficiency of a lipophilic polya- mine 1,1,7,7-tetraethyl-4-tetradecyldiethylenetriamine (TE14DT) towards the model ion Cu(II) in such dif-ferent media. The effect of temperature on the extraction efficiency was also investigated. The metal ion par-tition was found to be strongly dependent on both the nature of the solvent and on the working temperature. The viscosity of ionic liquids and the water content in ionic liquid were found to affect the extraction effi-ciency of TE14DT. The chemical nature of the cation of ionic liquids, and in particular the alkyl chain length on imidazolium ring, also seemed to be important in determining the efficiency of the extraction process. Finally, preliminary experiments on back-extraction of Cu(II) ions from ionic liquid also revealed interesting hints to the development of a continuous transport process.

Extraction of Tetracycline via Ionic Liquid Two-phase System

A new method to extract and separate tetracycline（TC） in a new aqueous tyro-phase system（ATPS） consisting of hydrophilic [Bmim]BF4 and NaH2PO4 was investigated. The effects of the amount of salt, ionic liquid as well as tetracycline on extraction efficiency were studied systematically. The results show that ionic liquid-ATPS exhibited the highest extraction efficiency higher than 90%. When the concentration of NaH2PO4 was 33.3%--38.5% （mass fraction）, the amounts of ionic liquid and TC were 1.0--2.0 mL and 1.8 mL, respectively, and ionic liquid could be re-used.

Th(Ⅳ) and U(Ⅵ) removal by TODGA in ionic liquids:extraction behavior and mechanism,and radiation effect

Extraction behavior of thorium(Ⅳ) and uranium(Ⅵ) from nitric acid(HNO_3) was studied using N,N,N',N'-tetraoctyldiglycolamide(TODGA) as extractant in different ionic liquids, and isooctane as comparison.Slope analyses with varying HNO_3 concentrations and diluents revealed the extraction mechanism. With increasing length of alkyl chain and HNO_3 concentration, the extraction mechanism of TODGA/IL system changed from cation exchange to neutral complex and/or anion exchange,and the molar ratio between TODGA and metal ions varied gradually from 2:1 to 1:1 for Th(Ⅳ) and 3:1 to 1:1 for U(Ⅵ). The kinetics and thermodynamic studies of Th(Ⅳ)and U(Ⅵ) by the best TODGA/[C_2mim][NTf_2] system showed that the extraction equilibrium was reached within 2 h and extraction reactions were endothermic. Compared to TODGA/isooctane system, TODGA/[C_2mim][NTf_2]system presented higher radiation stability under c-irradiation. Therefore, it would have a promising application in spent fuel reprocessing.

Anionic structural effect in liquid–liquid separation of phenol from model oil by choline carboxylate ionic liquids

Phenolic compounds exist in crude oil as pollutants, and their removal is vital important for the refining and further application of oils. In traditional separation approaches, strong acid and strong base have to be used to remove these compounds, which may cause serious environmental problems. In this work, 19 kinds of cholinium ionic liquids have been developed to separate phenol from model oil by liquid–liquid extraction. Structural effect of anions of the ionic liquids in the separation is systematically investigated. It is found that depending on the chemical structure of ionic liquids, phenol can be removed from toluene with single-step removal efficiency from 86 to 99% under optimal conditions. The type of substituent groups and the-CH_2 number between two carboxylates have obvious effect on the removal efficiency, and more hydrophilic ionic liquids have a stronger extraction performance for phenol. Furthermore, thermodynamic,^(13) C NMR,~1 H NMR and density functional theory calculations have been performed to characterize the extraction process and to understand the extraction mechanism. It is shown that the extraction of phenol from oil to ionic liquid is a favorable process, and this process is mainly driven by enthalpy change. The formation of the hydrogen bond between anion of the ionic liquid and-OH of phenol is the main driving force for the extraction of phenol from oil to the ionic liquids.

Solvent impregnated resin prepared using task-specific ionic liquids for rare earth separation

A novel bifunctional task-specific ionic liquid(TSIL),i.e.[trialkylmethylammonium][sec-nonylphenoxy acetate]([A336] [CA-100]) was impregnated on intermediate polarized XAD-7 resin,and the prepared solvent impreganated resin(SIR) was studied for rare earth(RE) separation.Adsorption ability of the SIR was indicated to be obviously higher than that prepared by [A336][NO3] because of the functional anion of [A336][CA-100].Adsorption kinetics,adsorption isotherm,separation and desorption of the SIR were also stu...

Effect of the Structure of Cations and Anions of Ionic Liquids on Separation of Aromatics from Hydrocarbon Mixtures

The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The .results showed that the corresponding separation factors were considerably larger than those of the traditional solvents （Benzene＋Hexane＋sulfolane）, and that the ionic liquids could be used as novel solvents for the separation of aromatics from hydrocarbon mixtures. The key parameters governing the ability of ionic liquids for separating aromatics from hydrocarbon sources were investigated. It was found that the effectiveness of the ionic liquids, based on the same anion, changed in the cation order of [BIqu]^＋〈 [BPy]^＋〈 [BMIM]^＋. The selectivity of the ionic liquid toward aromatics decreased apparently with the increasing length of the substituted alkyl chain of its cationic head ring. The separation factors, based on the same cation, changed in the anion order of [Tf2N]^-〈[PF6]^-〈[BF4]^-〈[C2H5SO4]^-. The solubilities of the aromatics were greater in the ionic liquids based on the former three anions than that in the ionic liquids involving [C2H5SO4]^-.

Separation of methyl linolenate and its analogues by functional mixture of imidazolium based ionic liquid-organic solvent-cuprous salt

Methyl linolenate was separated from its analogues by a new extraction system constructed by solvent,imidazolium based ionic liquids and cuprous salt. Firstly, the effect of ionic liquid on the dissolution of CuCl in acetonitrile, N,N-dimethylformamide(DMF), methanol and water was evaluated by visual observation.[C4Mim][Cl]can improve the dissolution of CuCl in acetonitrile. Then, for the new system as acetonitrile-ILs-CuCl, extraction equilibrium, distribution ratio and selectivity of methyl linolenate and its analogues were determined by gas chromatography analysis and the mass balance. The extraction time, IL structures and CuCl concentrations were investigated. Distribution ratio decreased slightly, but selectivity increased significantly with the addition of CuCl,[C4Mim][Cl] or [C4Vim][NTF2] into acetonitrile.[C4Vim][NTF2] had higher selectivity than [C4Mim][Cl].But the selectivity of the system combining CuCl with [C4Vim][NTF2] was much lower than with [C4 Mim][Cl].For the CuCl-[C4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu^+ concentration effectively improved the separation selectivity when ratio of CuCl/[C4Mim][Cl] was less than 1. Compared with previous aqueous AgNO3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.

Separation of m-cresol from aromatic hydrocarbon and alkane using ionic liquids via hydrogen bond interaction

Low temperature coal tar contained a large amount of phenols, aromatic hydrocarbons and alkanes;the separation of phenols from coal tar has a great significance to the deep processing of coal tar. In this work, the separation of m-cresol from cumene and n-heptane by liquid–liquid extraction using ionic liquids(ILs) as extractants was studied. The suitable ILs were screened by conductor-like screening model for real solvents(COSMO-RS)model and the liquid–liquid phase equilibrium(LLE) experiments were to verify the accuracy of the screening results. The extraction conditions such as extraction time, extraction temperature and mass ratio of ILs to model oils were evaluated. An internal mechanism of the m-cresol extract by ILs was revealed by COSMO-RS calculation and FT-IR. The results showed that the selected ILs can extract m-cresol effectively from cumene and nheptane, 1-ethyl-3-methylimidazolium acetate(emim CH3 COO) was the best extraction solvent. A hydrogen bond between anion of ILs and phenolic hydroxyl groups was observed. M-cresol in model oils could be extracted with extraction efficiencies up to 98.85% at an emim CH3 COO: model oils mass ratio of 0.5 and 298.15 K,emim CH3 COO could be regenerated and reused for 4 cycles without obvious decreases in extraction efficiency and extractant mass.

Application of ionic liquids in hydrometallurgy of nonferrous metals

Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.

Purification of Astaxanthin from Laminaria japonica by Ionic Liquid-based Monolithic Cartridge

An effective and accurate method was developed for the extraction of astaxanthin from Laminariajapo- nica with subsequent separation by ionic liquid-based monolithic cartridge. The optimized extraction conditions in- cluding extraction solvent（ethanol）, extraction time（90 min） and ultrasonic power（75 W） were obtained by systema- tical investigation. Chromatographic analysis was performed on a C18 column with ultraviolet（UV） detection at 476 nm, and a solution consisting of methanol/acetonitrile/H2O/dichloromethane（83：6：6：5, volume ratio） was used as the mobile phase at a flow rate of 0.7 mL/min. After ionic liquid-based monolithic solid phase extraction, 17.82 μg/g as- taxanthin was obtained from Laminaria japonica. This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin, and it can be potentially used as the stationary phase of high performance liquid chromatography（HPLC）.