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1.
Due to the extensive range of ionic liquids (ILs) used in industry, an efficient recovery method is needed. In this study, the effectiveness of a simultaneous concentration and recovery method was investigated for 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), an IL that was recovered using electrodialysis (ED). The optimal operational parameters for electrodialytic recovery were determined empirically. The variables that were investigated included the concentration of IL, applied voltage, linear flow velocity and the diluate-to-concentrate volume ratio. The recovery of [Emim]Cl, the concentration degree, the [Emim]Cl flux across membranes, the current efficiency, as well as the energy consumption were determined. The results of the experiments confirmed that [Emim]Cl concentration and recovery can be achieved using ED. The highest ED efficiency was obtained when a 2 V electric potential per one membrane pair was applied, using a 2 cm/s linear flow velocity, and by adjusting to 0.2 M IL in the feed solution. By using ED, a 2.35-fold concentration of [Emim]Cl with a recovery of 90.4% could be achieved when the diluate-to-concentrate volume ratio was 2. On the other hand, a 3.35-fold concentration of [Emim]Cl with a recovery of 81.7% could be obtained when the diluate-to-concentrate volume ratio was increased to 5.  相似文献   

2.
A reasonable project was presented for the extraction and separation of Pt(IV), Pd(II), Ru(III), and Rh(III) from the mixed imidazolium-based ionic liquids (ILs) [C6mim]Cl, [C6mim][NTf2], and [C6mim][DDTC]. Pt(IV) was first separated from other three platinum group metals with a mixture of [C6mim]Cl and [C6mim][NTf2]. Then, separation of Pd(II) and Ru(III) from Rh(III) was realized by changing the concentration of [C6mim][DDTC]. Back-extraction of Pt(IV), Pd(II), and Ru(III) from loaded hydrophobic phase and the recovery of Rh(III) in aqueous phase were also investigated. Mechanisms between Pd(II)/Ru(III) and [C6mim][DDTC] were further explored using ultraviolet spectrophotometry (UV-Vis), infrared spectrophotometry (FTIR), the method of continuous variations, ab initio quantum chemical studies, and X-ray crystallographic analysis. The results afford more directions for extracting and separating metals by introducing devisable functionalized group into ILs.  相似文献   

3.
Acidic ionic liquids (ILs) have been employed as extractant and catalyst in the oxidative desulfurization (ODS) process of fuels in recent years. Several Lewis acidic ionic liquids [C63MPy]Cl/nFeCl3 (molar fraction n = 0.5, 1, 2, 3) and [C6MIM]Cl/FeCl3 were prepared and used to remove the aromatic sulfur compounds dibenzothiophene and benzothiophene from fuels. In the ODS process, the used ILs acted as both extractant and catalyst with 30 wt % hydrogen peroxide aqueous solution as oxidant. The effects of Lewis acidity of ILs, IL's cation structure, molar ratio of O/S, reaction temperature, and different sulfur compounds on the sulfur removal of model oil were investigated. The results indicated that the sulfur removal for dibenzothiophene was affected by Lewis acidity of ILs and nearly reached 100 % by [C63MPy]Cl/FeCl3 at conditions of 298 K, IL/oil mass ratio of 1/3, O/S molar ratio of 4/1, in 20 min. The sulfur removal of real gasoline reached 99.7 % after seven ODS runs in the [C63MPy]Cl/FeCl3‐H2O2 system.  相似文献   

4.
《分离科学与技术》2012,47(8):1208-1214
The FeCl3-containing Lewis-acidic ionic liquids (ILs) [C6mim]Cl/FeCl3(1:1.5), [C6mim]Cl/FeCl3(1:2), [C8mim]Cl/FeCl3(1:1.5), and [C8mim]Cl/FeCl3(1:2) were used as extractants for desulfurization of model fuel and gasoline fuel, respectively. The results demonstrate that these ILs are effective for the removal of sulfur compounds from model fuel under different mass ratio of IL to model fuel (1:1, 1:3, 1:5, 1:10) at 25°C. The extractive performance of ILs increased as the molar ratio of FeCl3 to [Cnmim]Cl(n = 6, 8) varied from 1:1 to 1:2. The selectivity of sulfur compounds by extraction process followed the order of dibenzothiophene (DBT)>benzothiophene (BT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT). The sulfur removal of gasoline fuel containing sulfur content of 440.3 ppmw could be up to 85.8%; that is to say that the sulfur content of gasoline fuel varied from 440.3 ppmw to 62.4 ppmw after one extraction stage. Moreover, the [C6mim]Cl/FeCl3(1:2) can be recycled for at least 4 times with a little decrease in the desulfurization activity.  相似文献   

5.
Ionic liquids (ILs) have received much attention in both academia and industries due to their superior performance in many applications. Efficient recovery/recycling of ILs from their dilute aqueous solutions is essential for the acceptance and implementation of many IL-based technologies by industry. In this work, a practical and cost-effective hybrid process design method that combines aqueous two-phase extraction, membrane separation, and distillation operating at their highest efficiencies is proposed for the recovery of hydrophilic ILs from dilute aqueous solutions. The application of this hybrid process design method is illustrated through case studies of recovering two hydrophilic ILs, n-butylpyridinium trifluoromethanesulfonate ([C4Py][TfO]) (CAS number: 390423-43-5) and 1-butyl-3-methylimidazolium chloride ([C4mIm][Cl]) (CAS number: 79917-90-1), from their dilute aqueous solutions. For the recovery of 10 wt.% [C4Py][TfO] from aqueous solution, the hybrid process using (NH4)2SO4 as the salting-out agent could reduce the total annual cost (TAC) and energy consumption by 57% and 91%, respectively, compared with the pure distillation processes. In the case of recovering 10 wt.% [C4mIm][Cl] from aqueous solution, the reduction in TAC and energy savings of the hybrid process with salting-out agent (NH4)2SO3 could reach 49% and 87%, respectively, compared with the pure distillation process. Furthermore, uncertainty analysis through Monte Carlo simulations show that the proposed hybrid process design is more robust to uncertainties in energy prices and other material (e.g., equipment and solvent) costs.  相似文献   

6.
BACKGROUND: Separation and recovery of zinc from ammoniacal solutions with solvent extraction is very important in the hydrometallurgical industry. Ionic liquids (ILs) have considerable potential for the separation of metal ions. The extraction behaviour of zinc from ammoniacal solution into three hydrophobic ILs was investigated using β‐diketone as the extractant. RESULTS: The extraction efficiency of zinc for three ILs reached a maximum at pH 7.5 and subsequently decreased with increase of pH and it also decreases with increase of the total ammonia concentration. The overall extraction process is exothermic. The extractability decreases in the IL order: [BMIM]NTf2 > [OMIM]PF6 > [OMIM]NTf2. The results of X‐ray absorption spectra indicate that the coordination number of the extracted zinc complexes decreases with increase in the hydrophobicity of the ILs. The results of five recycling experiments indicate that the three hydrophobic ILs are more stable than [BMIM]PF6 for the extraction of zinc in ammoniacal solutions. CONCLUSION: Hydrophobic ILs combined with β‐diketone can be used to extract zinc from ammoniacal solutions. The extraction of zinc is dependent on the zinc species in ammoniacal solutions and the hydrophobicity of ILs. Moreover, the latter affects both the extractability of extraction systems and the structure of the extracted complexes. © 2012 Society of Chemical Industry  相似文献   

7.
A polymer of intrinsic porosity (i.e., PIM‐1) has been blended with different ionic liquids (ILs) in order to evaluate the effect of the ILs on the microstructure of the polymer blend. [C8MIM][Cl], [BMIM][DCa], [BMPyr][DCa], and [BMIM][Tf2N] have been selected and were mixed with PIM‐1. Polymer blends containing up to 80 wt % of ILs were prepared by a casting method with chloroform as solvent. SEM images show that during the film formation a structuring of the surface appears depending on the nature and the concentration of ILs, with appearance of well‐defined microstructure in the case of [BMIM][Tf2N] and [BMIM][DCa]. In the case of [BMIM][Tf2N]/PIM‐1 film, the lower IL concentration induces the denser film with small micropatterns onto the surface. AFM analysis indicates that the ILs are well dispersed on the surface. X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and water contact angle measurements show that a gradient of IL concentration is observed across the film thickness. It is demonstrated that ILs are versatile co‐solvents for inducing controlled micropatterns in polymer membrane surfaces. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46109.  相似文献   

8.
《分离科学与技术》2012,47(8):1166-1174
The inability of traditional hydrodesulfurization (HDS) to effectively remove aromatic sulfur compounds such as thiophene (TS) and dibenzothiophene (DBT) has called for alternative methods to be studied, among which extractive desulfurization using ionic liquids (ILs) has attracted increasing interest. In this work, we prepared a new IL, 1-butyl-3-methylimidazolium dicyano(nitroso)methanide ([C4mim][dcnm]), and investigated its extractive desulfurization for both model oils and real FCC gasoline, where model diesel fuel was composed of n-hexane and droplets of DBT and model gasoline was composed of n-hexane, toluene and droplets of TS. Other three [dcnm]-based ILs, 1-ethyl-3-methylimidazolium dicyano(nitroso)methanide ([C2min][dcnm]), N-ethyl-N-methylpyrrolidinium dicyano(nitroso)methanide ([C2mpyr][dcnm]), and N-butyl-N-methylpyrrolidinium dicyano(nitroso)methanide ([C4mpyr][dcnm]), were also comparatively investigated. These [dcnm]-based ILs have low viscosity which favors the mass transfer and reduces the extractive equilibrium time, also are fluorine-free which avoids the corrosion by hydrogen fluoride from anion decomposition that occurs generally in fluorine-containing ILs. The desulfurization ability follows the order [C4min][dcnm] > [C4mpyr][dcnm] > [C2min][dcnm] > [C2mpyr][dcnm]. Typically, [C4min][dcnm] is capable of removing 66% DBT and 53% TS from their respective model oils after one cycle (initial 500 ppm S, 25°C, 15 min, mass ratio of IL:oil 1:1), and < 10 ppm S-content can be obtained after 4 cycles. It was observed interestingly that the S-content in real FCC gasoline can be reduced from initial 250 ppm to < 30 ppm after 6 cycles using [C4min][dcnm] as extractive reagent, which is better than some previous results for real feedstocks. Mutual solubility, extractive temperature, IL:oil mass ratio, multiple extraction, initial S-content, and regeneration were also studied. These dcnm-based ILs are competitive extractive reagents compared with some other ILs to remove those aromatic S-compounds from fuel oils.  相似文献   

9.
The effect of two ionic liquids (ILs), namely, 1‐allyl‐3‐methyl imidazolium chloride ([AMIM]Cl) and 1‐ethyl‐3‐methyl imidazolium tetrafluoroborate ([EMIM]BF4), on the surface and volume resistivities, mechanical properties, transparency, and water contact angle of methyl vinyl silicone rubber (MVQ) were investigated. The chemical structures of the two ILs before and after heat treatment were characterized by Fourier transform infrared spectroscopy. The morphology and fluorine and chlorine elemental dispersion were characterized by field emission scanning electron microscopy and energy‐dispersive X‐ray spectroscopy mapping, respectively. The antistatic mechanism was revealed. The results show that the MVQ–[EMIM]BF4 composites had lower surface and volume resistivities than the MVQ–[AMIM]Cl composites. The mechanical properties of the MVQ–[EMIM]BF4 and MVQ–[AMIM]Cl composites were slightly lower than those of the pristine MVQ. With increasing [EMIM]BF4 content, the surface and volume resistivities and water contact angle of the MVQ–[EMIM]BF4 composites decreased. When the content of [EMIM]BF4 was 2.0 phr, the MVQ–[EMIM]BF4 composites showed better antistatic performance with lower surface and volume resistivities of 9.6 × 109 Ω and 1.2 × 1011 Ω cm, respectively. The antistatic mechanism of the MVQ–IL composites was ascribed to the synergistic effect of ionic migration and moisture absorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45180.  相似文献   

10.
Ten 1,3‐dialkylimidazolium‐based ionic liquids (ILs) have been investigated as media for the enzymatic synthesis of tricaprylin, in comparison with the conventional organic solvent hexane. The results suggested that the esterification activity of Novozym 435 was higher than Lypozyme RM IM in all the ILs assayed. Novozym 435 showed higher catalytic activity in ILs with anions Tf2N? and PF6? than in BF4? and hexane. FTIR analysis of the secondary structure of the lipase indicated that a smaller decrease of the α‐helix was observed in [C4MIM] Tf2N and [C4MIM] PF6 than [C4MIM] BF4 and hexane, indicating that the anions of ILs might be a key factor for the activity of lipase in ILs. Process parameters (amount of lipase, caprylic acid/glycerol molar ratio, temperature and their interactive effects) were optimized in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([C4MIM]PF6) using Novozym 435 by response surface methodology. When the reactions were performed with the lipase amount of 6.1 % substrate mass at a caprylic acid/glycerol molar ratio of 4.5:1 and 66.7 °C, a higher yield was reached up to 92.4 %.  相似文献   

11.
Abstract

We tested dissolution and regeneration of poplar wood using 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) and 1-butyl-3-methylimidazolium acetate ([C4mim]OAc). When 5wt% of poplar sawdust in [C4mim]OAc was stirred at 130°C, 96wt% of added poplar was dissolved in [C4mim]OAc, whereas 25.3wt% of poplar dissolved in [C4mim]Cl at the same reaction condition. Fourier transform infrared spectroscopy (FT-IR) and lignin content analysis revealed that poplar was partially delignified during the dissolution and regeneration processes. X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and microscopy were used to characterize raw poplar sawdust, undissolved poplar, and regenerated wood from the poplar-ionic liquid solution. The direct acetylation of poplar-[C4mim]OAc solution using acetyl chloride was also performed in the absence of any organic solvent. FT-IR analysis of the resulting wood sample revealed the formation of partially delignified acetylated-poplar.  相似文献   

12.
A new methyl chloride (CH3Cl) capture and dehydration process using two ionic liquids (ILs) was designed and systematically studied. ILs [EMIM][Ac] and [EMIM][BF4] were screened out as CH3Cl capture and drying absorbents through the COSMO-RS model. The result of solubility experiment suggests [EMIM][Ac] has an excellent solvent capacity for CH3Cl at mild operation conditions. The bench-scale CH3Cl absorption experiments further confirmed the outstanding CH3Cl capture ability of [EMIM][Ac]. Besides, the water content of outlet gas can be decreased to 452 ppm (mass fraction) using [EMIM][BF4] in the dehydration experiment. The industrial-scale CH3Cl capture and dehydration process was simulated and optimized. Compared to the benchmarked triethylene glycol process, IL process has higher product purity (99.99 wt%), and lower energy consumption. The quantum chemical calculations clearly revealed the relationship between hydrogen bond and separation performance. This study provides a decision-making basis for designing green process associated with volatile organic compounds.  相似文献   

13.
The study of CO2 absorption in ionic liquids (ILs): [Emim] [Ac], [Bmim] [Ac] in a packed column is presented. The influence of mass transfer resistances, initial CO2 concentration, absorption temperature and 2, 5, 10% wt. water addition on CO2 removal efficiency was investigated. The resistance in series model and estimated values of enhancement factor were used to predict with good accuracy mass fluxes of absorbed carbon dioxide for both ILs. The CO2 absorption efficiency in packed column depends on temperature and initial CO2 concentration. The addition of small amounts of water to [Emim][Ac] is of minor effect on CO2 absorption.  相似文献   

14.
《分离科学与技术》2012,47(5):663-669
Both hydrophibic [C8mim][PF6] and [C4mim]Cl/(K2CO3, K2HPO4 or K3PO4) aqueous biphasic system (ABS) were employed for the enrichment of aromatic compounds including nitrobenzene, 4-nitrophenol, phenol and aniline from aqueous solutions. In [C8mim][PF6] enrichment system, the distribution ratio (D) of nitrobenzene and aniline increase with the increasing of pH values of aqueous phase from 2 to 8, but there is no obvious change for 4-nitrophenol and phenol. And the D values of the aromatic compounds decrease with the phase ratio change from 1/5 to 1/30 (IL phase volume/aqueous phase volume). In [C4mim]Cl/(K2CO3, K2HPO4 or K3PO4), the distribution ratio increase with the increasing of the salts concentrations. The distribution ratio order in [C8mim][PF6] and [C4mim]Cl/kosmotropic salt ABS is nitrobenzene > phenol > aniline > 4-nitrophenol. It is expected that these results are promising for the removal of the aromatic compounds from water, especially for sample enrichment in analytical science.  相似文献   

15.
A coordinating ionic liquid (IL), 1‐[(diethyl amine)amine]ethyl‐3‐methyl imidazolium chloride ([N3MIM]Cl), was prepared as an alternative to a simple organic ligand to coordinate to copper(I) bromide (CuBr). We, thereby, obtained a novel catalyst for atom transfer radical polymerization (ATRP) reactions. This catalyst was applied to the ATRP of methyl methacrylate in the IL 1‐allyl‐3‐methyl imidazolium chloride ([AMIM]Cl). The chemical structures of the ILs obtained were confirmed by Fourier transform infrared spectroscopy, mass spectrometry, and 1H‐NMR analyses. The coordination ability of [N3MIM]Cl was assessed by cyclic voltammetry, and the redox potential of [N3MIM]Cl–CuBr was ?0.507 V. The [N3MIM]Cl–CuBr complex was expected to be a markedly more active catalyst than the amine DETA–CuBr complex. The coordination mode toward CuBr was also examined. The [N3MIM]Cl–CuBr catalyst system showed good controllability in the aforementioned ATRP reaction in [AMIM]Cl. The Cu catalyst was easily separated from the obtained polymer with the coordinating IL as a ligand. Consequently, the coordinating IL overcame the shortcomings of traditional organic ligands, such as poor compatibility with IL media and poor separation of the catalyst from the polymer; this makes it highly promising for applications in the ATRP field. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45484.  相似文献   

16.
17.
Electrodialysis (ED) has been recently known as a highly effective technique to remove and recover ionic liquids from aqueous solution. When a conventional electrolyte solution for the ED process containing Na2SO4 was used, a recovery ratio of an acidic IL, 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim][HSO4]), was 90%. On the other hand, the value clearly increased to 96% when we employed [Bmim][HSO4] as the electrolyte solution. In an acid hydrolysis of bagasse using the IL under microwave irradiation, the recovery ratio maintains 96%, irrespective of reaction time. This demonstrates the applicability of the proposed ED system in biomass processing.  相似文献   

18.
A comparative study was made of lipase‐catalyzed acylation of konjac glucomannan (KGM) with vinyl acetate as the acyl donor in five ionic liquids (ILs) and also in the presence of the organic solvent tert‐butanol (t‐BuOH). An obvious enhancement in enzyme activity and stability was observed using ILs as the reaction media when compared with t‐BuOH. The maximum degree of substitution (DS) of the modified KGM in ILs and t‐BuOH under the conditions employed is 0.71 and 0.54, respectively. The water activity (aw) of the reaction system affected the acylation of KGM to some extent. 1‐Butyl‐3‐methylimidazolium tetrafluoroborate (C4MIm.BF4) was the best IL medium for the reaction, and an aw of 0.75 was optimum. It was also found that the nature of both the cation and the anion of ILs had an effect on the reaction. Candida antarctica lipase B immobilized on an acrylic resin (Novozym 435) displayed no acylation activity to KGM in 1‐butyl‐3‐methylimidazolium chloride (C4MIm.Cl). The optimum reaction temperature for enzymatic acylation in ILs was shown to be 45‐55 °C. Enzymatic acylation of KGM in IL‐t‐BuOH co‐solvent systems was also investigated. When an appropriate amount of t‐BuOH was added to ILs, the DS of the modified KGM was enhanced. Additionally, the enzymatic acylation of KGM in all the media examined was shown to be regioselective, with acylation occurring predominantly at the C‐6‐OH. Copyright © 2006 Society of Chemical Industry  相似文献   

19.
BACKGROUND: The fast development of practical applications of photopolymerizable compositions (PPCs) leads to a growing demand for the elaboration of novel monomers and simultaneously for the investigation of three‐dimensional polymerization mechanisms including the possible influence of initiator, additives, etc. The aim of the current study is to explore and clarify the role of ionic liquids (ILs) as environmentally friendly catalytic additives in the photopolymerization of poly(ethylene glycol dimethacrylate)s. RESULTS: The photopolymerization of triethylene glycol dimethacrylate (TEGDM) and poly(ethylene glycol‐400 dimethacrylate) (PEGDM) in the presence of various ILs both imidazolium‐based, i.e. [1‐methyl‐3‐alkylim]+ (CF3SO2)2N? (im = imidazolium; alkyl = C2H5, C4H9, C14H29), and phosphonium‐based, i.e. [P+ (C6H13)3(C14H29)]X? (X? = PF6?, BF4?, (CF3SO2)2N?, Cl?), as catalytic additives was investigated. The influence of the concentration of the ionic salts as well as the nature of the ILs upon the photopolymerization was studied in detail. It was found that imidazolium ILs accelerate TEGDM photopolymerization and suppress the polymerization of PEGDM. In contrast, polymerization of PEGDM with extra small amounts of phosphonium ionic solvents proceeded at a high rate and offered access to new polymers and the utilization of low‐reactivity monomers in PPCs. CONCLUSION: The most striking advantage is that the use of certain ILs permits the control of polymerization rate to achieve maximum oligomer conversion. Copyright © 2007 Society of Chemical Industry  相似文献   

20.
《分离科学与技术》2012,47(5):1083-1090
Abstract

Aqueous solutions of water‐structuring, kosmotropic salts (e.g., salts of PO4 3?, HPO4 2?, CO3 2?) will salt‐out water‐destructuring chaotropic ionic liquids (ILs) (e.g., 1‐butyl‐3‐methylimidazolium chloride, ([C4mim]Cl)) forming salt/salt aqueous biphasic systems (ABS). The chaotropic pertechnetate (TcO4 ?) anion will partition without the use of an extractant into the IL‐rich phase. These complex salt/salt ABS are not unlike the complex and salt‐rich Hanford tank waste, and thus have been used here as a simple model to show effectiveness in the partitioning of TcO4 ? from such tank waste into an IL‐rich phase.  相似文献   

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