Thermal Performance Analysis of Ionic Liquid-Pretreated Spent Coffee Ground Using Aspen Plus®

Thermal analysis and gasification study of spent coffee ground (SCG) pretreated with ionic liquids (ILs) is presented. Four ILs, namely, 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]), tributylmethylammonium chloride ([N₁₄₄₄][Cl]), and trihexyltetradecylphosphonium chloride ([P₆₆₆₁₄][Cl]), were investigated. The pretreatment was followed by thermogravimetric analysis. The syngas composition was computed using an equilibrium-based steam-O₂ gasification model developed in Aspen Plus® by varying gasifier temperature and steam/biomass ratio. All ILs reduced the ash content, enhanced the volatility as well as the higher heating value of SCG. IL pretreatment also decreased CO₂ and CH₄ contents showing environmental benefits of using ILs.     

离子液体催化丁醇与盐酸反应制备丁基氯

The catalytic performance of some quaternary ammonium salts for the liquid phase reaction of butanol and hydrochloric acid at different conditions was studied experimentally and compared with the traditional catalyst （ZnCl2）. The organic ammonium catalysts investigated include ionic liquids N-butyl-N-methyl imidazolium fluoborate （[BMIM][BF4]） and N-butyl-N-methylimidazolium chloride （[BMIM]Cl） as well as hydrochloric salts of N-methylimidazol （[HMIM]Cl）, pyridine （[HPy]Cl） and triethylamine （[HEt3N]Cl）. It is shown that the intrinsic catalytic performance of all organic ammonium salts except [HEt3N]Cl is slightly superior to ZnCl2, while the selectivity of butyl chloride is nearly at the same level around 96%. The conversion of butanol increases slightly with temperature and the catalyst amount added while the variation of selectivity is not obvious. Based on the recycle experiments, the ionic liquids as catalyst for the reaction of butanol and hydrochloric acid can be used more than 5 times, which suggests great potential of using ionic liquids as novel catalyst for such reactions.     

Solubility of CO2 in three cellulose-dissolving ionic liquids

The solubility of CO₂ in three cellulose-dissolving ionic liquids (1-ethyl-3-methylimidazolium diethylphosphate, [Emim][DEP], 1-allyl-3-methylimidazolium chloride, [Amim][Cl], and 1-butyl-3-methylimidazolium chloride, [Bmim][Cl]) at temperatures within 298 and 356 K and pressures up to 6.5 MPa was determined using a Van Ness-type apparatus (static isochoric). It was demonstrated that this device can work in isothermal and isoplethal modes, being the latter faster and more precise. Moreover, it was possible to determine CO₂ solubilities in metastable liquid [Bmim][Cl]. Experimental data were modeled using the Extended Henry's law correlation and the group contribution equation of state. New parameters for the binary interaction of CO₂ with ionic liquid groups were calculated.     

微波辅助离子液体制备及催化降解聚酯

采用微波辅助离子交换法,以氯化1-丁基-3-甲基咪唑([Bmim]Cl)和氯化锌为原料,合成了1-丁基-3-甲基咪唑氯锌酸盐离子液体,并考察了合成过程中溶剂对离子液体合成的影响。进一步以制备的离子液体为催化剂,乙二醇为溶剂,采用微波辅助乙二醇醇解聚对苯二甲酸乙二醇酯(PET)。以对苯二甲酸的回收量为指标,分别考察了离子液体用量、反应温度、时间以及溶剂用量对PET降解反应的影响。结果表明,采用微波辅助离子交换法在30 min内即可合成得到相应的离子液体,以二氧六环为溶剂时,3种产物的产率均高于90%。在微波加热的条件下,离子液体[Bmim][Zn2Cl5]对PET的乙二醇醇解反应具有较好的催化性能,对苯二甲酸的产率超过20%。     

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. [C_4Mim][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, [C_4Mim][Cl] or [C_4Vim][NTF_2] into acetonitrile. [C_4Vim][NTF_2] had higher selectivity than [C_4Mim][Cl].But the selectivity of the system combining CuCl with [C_4Vim][NTF_2] was much lower than with [C_4 Mim][Cl].For the CuCl-[C_4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu~+ concentration effectively improved the separation selectivity when ratio of CuCl/[C_4Mim][Cl] was less than 1. Compared with previous aqueous AgNO_3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.     

Hydrolysis reaction of poly(ethylene terephthalate) using ionic liquids as solvent and catalyst

The hydrolysis of poly(ethylene terephthalate) (PET) was studied using ionic liquid 1‐n‐butyl‐3‐methylimidazolium chloride ([Bmim][Cl]) as solvent and acid‐functionalized ionic liquid 1‐methyl‐3‐(3‐sulfopropyl)‐imidazolium hydrogen sulfate ([HSOpmim][HSO₄]) as catalyst. The effects of temperature, time, and dosages of solvent and catalyst on hydrolysis results were examined. Under the optimum conditions of m(PET) : m(H₂O) : m([Bmim][Cl]) : m([HSOpmim][HSO₄]) = 3 : 4 : 6 : 0.6, reaction temperature 170°C and time 4.5 h, the conversion of PET and the yield of terephthalic acid (TPA) were almost 100% and ≥88%, respectively. After easily separated from the product, the ionic liquids could be reused eight times without obvious decrease in the conversion of PET and yield of TPA. Hence, an environmental friendly strategy for chemical recycling of PET was developed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Performance and pressure drop of CO2 absorption into task-specific and halide-free ionic liquids in a microchannel

The gas–liquid two-phase flow pattern, absorption rate and pressure drop of CO₂ absorbed into the aqueous solution of the task-specific ionic liquids (1-aminopropyl-3-methylimidazole tetrafluoroborate [Apmim][BF₄] and 1-hydroxyethyl-3-methylimidazole tetrafluoroborate [OHemim][BF₄]) and halide-free ionic liquid 1-butyl-3-methylimidazolium methylsulfate [Bmim][CH₃SO₄] were investigated in a microreactor. The absorption mechanism of the three ionic liquids was analyzed employing the ¹³C NMR spectroscopy. The [Apmim][BF₄] was found to have the best ability of CO₂ capture compared with the other two ionic liquids, as chemical absorption occurred between [Apmim][BF₄] and CO₂, while only physical absorption took place between [OHemim][BF₄]/[Bmim][CH₃SO₄] and CO₂. The sequence of CO₂ absorption rate in three ionic liquids aqueous solutions is: [Apmim][BF₄] > [Bmim][CH₃SO₄] > [OHemim][BF₄]. Furthermore, the effects of gas–liquid flow rate and ionic liquids concentration on CO₂ absorption rate and pressure drop were studied, the pressure drop models based on various flow patterns were proposed.     

SO2 Absorption/Desorption Characteristics of Two Novel Phosphate Ionic Liquids

Two kinds of phosphate ionic liquids were synthesized and their SO₂ absorption performance was investigated. It was found that both ionic liquids could readily absorb SO₂, and the absorption capacity could reach 2.8 and 2.7 mol SO₂ per mole ILs, respectively, at ambient temperature and under normal pressure. Moreover, the cycle of SO₂ absorption and desorption from ionic liquids was repeated for four times and no change in the absorption capacity was observed. FT-IR spectrum and ¹H NMR were used to characterize the microstructure of SO₂-absorbed ILs and ILs, analysis showed that both ionic liquids absorbed SO₂ purely by physical absorption. Comparing with the previous reported ionic liquids such as [Bmim][PF6] and [Emim][BF4], the synthesized ionic liquids showed higher absorption capacity, due to the anion based phosphate (O?P?O) with the free electrons on the oxygen interacting with the Lewis acidic sulfur of SO₂, and then showing a great affinity for SO₂.     

Modified g-C3N4 derived from ionic liquid and urea for promoting visible-light photodegradation of organic pollutants

In this work, modified g-C₃N₄ was fabricated successfully by calcination of ionic liquid (IL) and urea. The addition of IL changed the polymerization mode of urea, induced the self-assembly of urea molecules, modified the morphological structure of the tightly packed g-C₃N₄, and extended the electron conjugation system. When using 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as a modifier, the heteroatom Cl could be inserted into the g-C₃N₄ to optimize the electronic structure. The results of characterizations indicate that the unique structure of modified g-C₃N₄ has an expanded electron delocalization range, introduces an interlayer charge transmission channel, promotes the charge transmission, reduces the band gap, enhances the absorption of visible light, and inhibits electron-hole recombination. Modified g-C₃N₄ showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline. Furthermore, the effect of different anions in 1-butyl-3-methylimidazolium salts ([Bmim]Cl, [Bmim]Br, [Bmim][BF₄], and [Bmim][PF₆]) on the structure and function of g-C₃N₄ are discussed.     

The effect of protic ionic liquids incorporation on CO2 separation performance of Pebax-based membranes

The separation of carbon dioxide (CO₂) is of great importance for environment protection and gas resource purification. The ionic liquids (ILs)-based gas separation membrane provides a new chance for efficient CO₂ separation, while high permeability and selectivity of membranes is a great challenge. In this study, the influence of two protic ILs with different anion ([TMGH][Im] and [TMGH][PhO]) on the CO₂ separation performance of the prepared ILs/Pebax blended membranes were systematically investigated at different temperature. The results showed the CO₂ permeability exhibits the rising trend for ILs/Pebax blended membranes with the increment of IL content. Especially, the [TMGH][Im] with low viscosity and high CO₂ absorption capacity leads to the blended membranes showing better CO₂ permeability and ideal CO₂ selectivity than that of membranes with [TMGH][PhO] at high IL content. Besides, with operating temperature increasing, the gas permeability of 20% (mass) [TMGH][Im]/Pebax blended membrane increases due to the decreasing viscosity of IL and the rising chain mobility of polymer. Inversely, the gas selectivity shows decreasing trend because CO₂ absorption capacity obviously decreased at higher temperature.     

含离子液体乙腈-正丙醇体系的等压汽液平衡

常压(101.3 kPa)下, 测定了如下体系的汽液平衡数据:乙腈-正丙醇-氯化1-苄基-3-甲基咪唑([BzMIM][Cl])、乙腈-正丙醇-溴化1-苄基-3-甲基咪唑([BzMIM][Br])、乙腈-正丙醇-溴化1-己基-3-甲基咪唑([HMIM][Br]), 考察了3种离子液体对乙腈-正丙醇体系相平衡行为的影响。实验结果表明, 3种离子液体都能够提高乙腈对正丙醇的相对挥发度, 3种离子液体提高相对挥发度的顺序为 [BzMIM][Cl] > [BzMIM][Br] > [HMIM][Br]。用NRTL模型对测得的汽液平衡数据进行了关联, 关联结果与实验结果具有良好的一致性。     

Effect of small amount of water on the dynamics properties and microstructures of ionic liquids

A series of systems of 1‐butyl‐3‐methylimidazolium acetate ([Bmim][Ac]), 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim][BF₄]), and 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][Tf₂N]) with a small amount of water were simulated. Viscosities of systems were obtained by nonequilibrium molecule dynamics simulation and the results show that the viscosities change in different ways: for [Bmim][BF₄] and [Bmim][Tf₂N], viscosities decrease rapidly in the first stage, and then decrease slowly with the increase of water content. But for [Bmim][Ac], the viscosities increase first and then decrease. The unique phenomenon of [Bmim][Ac] can be attributed to the formation of chain‐like structure of anion???water???anion???. Hydrogen bond (HB) interaction between ion pairs is weakened, but the number of HB between water and anions increases with increase of water content. Besides, the microstructures of water in ionic liquids‐water systems were compared and found that the distribution of water is more concentrated in [Bmim][Tf₂N]‐H₂O system, while it is isotropy in [Bmim][Ac]‐H₂O system. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2248–2256, 2017     

乙腈+[C4mim][Cl]、乙腈+[C4mim][BF4]、乙腈+[C6mim][Cl]的气液平衡测定与关联（英文）

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ([C6mim][Cl]) at temperatures of 313 to 353 K by a quasi-static method. The experimental data for the binary sys-tems were correlated by the non-random two liquid (NRTL) equation with an average absolute relative deviation (AARD) of within 1.84%. The results indicate that the three ionic liquids (ILs) can result in a negative deviation from the Raoult's law for the binary solutions containing acetonitrile, and the affinity between ILs and acetonitrile mole-cules fol ows the order [C4mim][BF4]+acetonitrile N [C4mim][Cl]+acetonitrile N [C6mim][Cl]+acetonitrile.     

离子液体催化1-己烯齐聚反应的研究

分别以氯化1-丁基-3-甲基咪唑和盐酸三乙胺为阳离子,氯化铝和氯化铁为阴离子合成酸性离子液体催化剂,用于1-己烯齐聚反应研究。结果表明,以［Bmim］Cl-AlCl₃制备的催化剂活性和选择性较好。较佳工艺条件为：催化剂用量为1-己烯质量的4%,n(氯化铝)∶n(咪唑)=2.5∶1,反应时间3 h,反应温度160 ℃。气相色谱分析可知,1-己烯转化率70%以上,产物主要是二聚、三聚、四聚和较少的五聚物,没有裂解产品。     

Solubilities of small hydrocarbons,viscosities of diluted tetraalkylphosphonium bis(2,4,4‐trimethylpentyl) phosphinates

Tetraalkylphosphonium bis(2,4,4‐trimethylpentyl)phosphinates show large solubilities for methane, ethane, ethylene, and propane. In these ionic liquids, solubilities of ethane are larger than those of ethylene. Therefore, these ionic liquids may be useful solvents for separation of ethane and ethylene; because the vapor pressure of ethylene is higher than that of ethane, the relative volatility ethylene/ethane is enhanced. However, the viscosities of these ionic liquids are too high for an industrial process. Low‐viscosity 1‐butyl‐3‐H‐imidazolium acetate([BHMIM][AC]) is a suitable diluent for reducing the large viscosities of trihexyl tetradecylphosphonium bis(2,4,4‐trimethylpentyl) phosphinate ([P(14)666][TMPP]) and tetrabutylphosphonium bis(2,4,4‐trimethylpentyl) phosphinate ([P4444][TMPP]). Addition of 20 wt % [BHMIM][AC] gives a dramatic drop in the viscosities of these ionic liquids. Mixtures of [P(14)666][TMPP] or [P4444][TMPP] with 20 or 50 wt % [BHMIM][AC] show high solubilities for the four solutes when compared with those in other ionic liquids. In these mixtures, the solubility for ethane is higher than that for ethylene. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2607–2612, 2014     

Vapor pressure measurement and correlation of acetonitrile+1-butyl-3-methylimidazolium chloride,+1-butyl-3-methylimidazolium tetrafluoroborate,and+1-hexyl-3-methylimidazolium chloride

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ...     

Electrodeposition of nanocrystalline copper thin films from 1-ethyl-3-methylimidazolium ethylsulphate ionic liquid

Copper thin films are increasingly important as interconnectors for the creation of smaller and better performing integrated circuits and electrodeposition from ionic liquid-based electrolytes could provide a greener fabrication method for these films. The electrodeposition of copper from copper(I) and copper(II) salt solutions in a low cost, widely available ionic liquid, 1-ethyl-3-methylimidazolium ethylsulphate, was studied using a range of different deposition potentials and temperatures. Three different electrolytes containing ~0.1 M of copper(I) chloride(CuCl), copper(II) chloride (CuCl₂) and copper(II) sulphate (CuSO₄) were used. Under similar deposition conditions, the films obtained from CuCl and CuSO₄-based electrolytes presented better continuity than films obtained from CuCl₂-based electrolyte. Continuous films with a homogeneous structure were obtained by electrodeposition from CuCl and CuSO₄-based solutions at a constant potential of ?1.8 V and a temperature of 35 °C. Under similar deposition parameters, the films deposited from CuCl₂-based electrolyte presented the largest particle size, while those deposited from copper(I) chloride and CuSO₄-based solutions presented finer microstructures. X-ray diffraction analysis and energy dispersive X-ray spectroscopy showed that the deposits were crystalline and consisted mainly of copper, with traces of oxygen and sulphur resulting from residues of the ionic liquid. The films presented a nanocrystalline microstructure consisting of particles about 25 nm, aggregated in clusters.     

Electrodeposition of Nickel on Glassy Carbon Electrode from Protic Ionic Liquids with Imidazolium Cation

The electrodeposition of nickel (Ni) on glassy carbon electrode was performed in a variety of six imidazolium based protic ionic liquids (PILs) like 2-methylimidazolium lactate ([Hmim][lactate]), 1-ethylimidazolium lactate ([Heim][lactate]), 1-butylimidazolium lactate ([Hbim][lactate]), 2-methylimidazolium glycolate ([Hmim][glycolate]), 1-ethylimidazolium glycolate ([Heim][glycolate]), 1-butylimidazolium glycolate ([Hbim] [glycolate]), respectively at various concentrations. While examining the course of the deposition process using cyclic voltammetry, the results demonstrate that all PILs possess high electrochemical stability with good electrochemical window ranging 1.61–3.6 V. In addition, [Hmim][lactate] and [Hmim][glycolate] showed greater cathodic stability, due to the replacement of C-2 acidic proton in imidazolium cation with methyl group. The Ni electrodeposition is found to be proceeding via one step—two electron transfer process that involved the irreversible reduction of Ni (II) to Ni (0). Also, it was found that by increasing Ni (II) concentration, nickel electrodeposition becomes more facile. Moreover, it was observed that owing to their high ionic conductance, the Ni electrodeposition was more facile in [Hmim][lactate] and [Hmim][glycolate] with diffusion co-efficient 1.8 × 10^?5 and 5.1 × 10^?7, respectively. The electrodeposited Ni was characterized using scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. The distinctive uniform,sponge and gravel-like morphologies of Ni deposits were confirmed by SEM images and the EDX analysis endorse the presence of Ni element.     

SO2／离子液体体系热力学性质的分子动力学模拟

为研究SO2对咪唑类普通离子液体输运特性、体积的影响,本文通过分子动力学方法模拟了293．15K时,常压下[bmim][PFs]和[bmim][BF4]与soz的？昆合物。结果表明,咪唑类普通离子液体的扩散系数随气体溶质摩尔分数的增加而增大,粘度则相应减小。吸收SO2对离子液体体积的影响极小。混合物摩尔体积随SO2摩尔分数增加呈直线下降。     

咪唑类离子液体混合物用于二氧化硫高效吸收

开发易制备、价格便宜、面向SO₂气体高效分离的离子液体（ILs）,是当前ILs从实验探索迈向工业应用的难点与重大挑战。合成了不同摩尔比（3∶1、2∶1、1∶1、1∶2和1∶3）的1-乙基-3-甲基咪唑氯盐（[Emim][Cl]）和1-乙基-3-甲基咪唑乙酸盐（[Emim][OAc]）的离子液体混合物[Emim][Cl]_x[OAc]_1-x, 在测定其密度、黏度、热稳定性等基本物性数据的基础上,研究了[Emim][Cl]_x[OAc]_1-x混合物在不同温度和SO₂分压下的SO₂吸收能力。结果表明,[Emim][Cl]_x[OAc]_1-x能够有效地捕获SO₂。[Emim][Cl]与[Emim][OAc]之间存在协同促进作用,有利于实现SO₂高效吸收。[Emim][Cl]_0.33[OAc]_0.66混合液在1.0和0.2 atm（1 atm=101325 Pa）下捕获SO₂量分别为（1.34±0.08）和（0.74±0.05） g/g,与现有结果相比,混合物在SO₂捕获方面有明显优势。此外,这些离子液体混合物对二氧化硫的吸收和解吸具有良好的可逆性。