基于COSMO-RS模型的分离油酚混合物的离子液体萃取剂筛选

低温煤焦油中酚类化合物的分离对其充分利用具有重要意义。基于COSMO-RS模型,以间甲酚和异丙苯作为模型化合物,研究了离子液体在分离油酚体系中的应用;利用Turbomole软件建立了包含27种离子液体阴离子和48种离子液体阳离子的s-图谱数据库,结合COSMOtherm软件对组成的1296种离子液体进行筛选,探讨了阴阳离子对间甲酚分离效果的影响,并对筛选得到适宜的离子液体进行液液相平衡实验验证。结果表明,离子液体阴离子对间甲酚分离效果影响较大,以Cl^-和CH₃COO^-为阴离子的离子液体与间甲酚之间具有较强的氢键相互作用,因此具有较好的分离效果;阳离子对间甲酚分离效果影响较小,碳链或支链的增加能适当提高离子液体对间甲酚的分离效果。实验得到的bmimOAc、bmimCl、emimOAc、TPAC四种离子液体-间甲酚-异丙苯的液液相平衡数据表明,四种离子液体对间甲酚均具有较大的分配系数和选择性,且萃取分离效果的顺序为：emimOAc > bmimOAc > TPAC > bmimCl,与COSMO-RS模拟筛选得到的结果一致,表明筛选具有较高的准确性。     

COSMO-RS筛选桉叶油萃取精馏的离子液体

采用COSMO-RS方法预测1,8-桉叶油素、柠檬烯、对聚散花素和γ-松油烯在离子液体中的选择性和溶解能力。结果表明:对选择性和溶解能力影响最好的阴离子为[NTf_2]~-。阳离子对1,8-桉叶油素、柠檬烯、对聚散花素和γ-松油烯的选择性和溶解能力一般遵从如下规律:溶解能力的强弱和选择性大小呈现相反的趋势;离子液体中烷基取代基的碳链长度越长、数目越多,与桉叶油的溶解能力越强,选择性反而越弱。含有羧基、羟基、胺基及不完全取代的铵盐类离子液体在分离1,8-桉叶油素的实际应用中前景较好。     

基于COSMO-RS方法筛选离子液体分离乙酸乙酯-乙腈共沸物

采用COSMO-RS方法探究了不同离子液体在分离乙酸乙酯-乙腈共沸物系中的应用;通过预测值与实验值的对比,验证了COSMO-thermX预测离子液体分离效果的准确性。离子液体的选择性和不同离子液体对乙酸乙酯-乙腈近沸点处相对挥发度的影响为指标,计算和分析了17种阳离子和13种阴离子组成的221种离子液体对乙酸乙酯-乙腈共沸物系的分离效果的影响规律。结果表明,含有[OAc]^－和[Cl]^－的离子液体对于乙酸乙酯-乙腈混合物的分离具有更好的促进效果,而阳离子的变化对于乙酸乙酯-乙腈混合物分离的促进效果差异较小。应用表面电荷密度分布（σ-profile）进一步研究了阴离子[OAc]^－和[Cl]^－对共沸物的影响,研究发现,阴离子[OAc]^－和[Cl]^－对乙酸乙酯-乙腈的分离效果影响顺序为[OAc]^－>[Cl]^－;综合筛选结果,得出离子液体[BMIM][OAc]有望在乙酸乙酯-乙腈共沸混合物分离过程中成为一种高效的萃取剂。     

COSMO-RS模型在离子液体/低共熔溶剂筛选中的应用研究进展

离子液体(ILs)和低共熔溶剂(DESs)作为一类新型的绿色溶剂,由于其独特的物理化学性质,在混合物分离方面已经受到了研究者的广泛关注,因此逐渐成为绿色化学领域的研究重点。针对特定的分离过程,选择合适的溶剂是非常重要的,然而,由于ILs和DESs种类较多,结构复杂,通过实验的方法逐一进行筛选费时费力、成本高,且几乎不可能找到最优选择,因此应用理论计算模型对ILs和DESs进行筛选是非常有必要的。真实溶剂类导体屏蔽模型(COSMO-RS模型)是一种由量子化学计算与统计热力学方法相结合的预测模型,它可以在不需要实验数据的情况下预测液体混合物的热力学性质,已经被研究者广泛用作各种分离问题的快速筛选工具。整理了应用COSMO-RS模型筛选ILs/DESs用于各种油中酚类、含氮化合物、含硫化合物、萜类化合物、天然维生素E的萃取分离,以及CO₂捕获和共沸混合物等的分离过程,表明COSMO-RS模型用于特定混合物萃取溶剂的筛选是快速有效的,可为难分离混合物分离过程中ILs/DESs的预筛选提供有价值的参考。     

新型离子液体用于芳烃、烯烃与烷烃分离的初步研究

The separation of aromatic hydrocarbons or olefins from paraffins is very important in chemical industry. The volatile organic solvents used are usually harmful to environment and human health. As green solvents, room temperature ionic liquids are potential substitutes for the separation of hydrocarbon products. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes,alkylbenzenes and styrene, in 1-butyl-3-methyl imidazolium hexafluorophosphate ( [BMIM] [PF6]), 1-allyl-3-methylimidazolium tetrafluoroborate ( [AMIM] [BF4] ), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ( [MPMIM] [BF4]) and [MPMIM] [BF4] AgBF4 were determined by gas-liquid chromatography. The measurements were carried out at different temperatures between 298.15 K and 318. 15 K. The separation effects of these ionic liquids for olefin/paraffin, alkanes/benzene and hexene isomers were discussed.     

基于COSMO-SAC模型的分子筛选方法用于咪唑类离子液体吸收甲苯蒸气

采用基于COSMO-SAC模型的分子筛选方法,对作为甲苯蒸气吸收剂的咪唑类离子液体进行了筛选。建立了100种常见的N,N'-二烷基咪唑阳离子与阴离子构成的咪唑类离子液体的s-谱图,在此基础上计算了303.15 K下离子液体对甲苯的吸收势,并以此为热力学评价标准对吸收剂进行筛选。选取6种离子液体进行甲苯蒸气的吸收实验,通过其饱和吸收量验证此方法的可行性。研究表明,实验和分子筛选结果相吻合。利用Gaussian 09软件进行微观结构分析,计算了离子液体阳离子与甲苯的相互作用能。对进气浓度和进气速度等动力学因素的影响进行探究,在条件为303.15 K、进气浓度为10000 mg·m^-3、进气速度为0.05 m³·h^-1情况下,离子液体对甲苯的初始吸收率高达96.2%。此外,实验验证了离子液体随着重复利用次数的增加,其吸收效果基本不变。     

离子液体脱除SO2技术的研究进展

离子液体(ILs)具有独特的物理化学性质,在烟气脱硫领域引起了广泛的关注.本文综述了近年来离子液体在脱硫方面的研究进展,介绍了离子液体(ILs)的特点和用于烟气脱硫的优势,评述了胍类、醇胺类、咪唑类和己内酰胺类等脱硫离子液体的溶解性能、吸收机理以及优缺点.ILs吸收SO2有物理吸收、化学吸收以及二者同时存在的3种机理,...     

基于COSMO-RS模型研究基团修饰[EMIM][OAC]的离子液体对乙腈-水汽液平衡的影响

以1-乙基-3-甲基咪唑醋酸盐([EMIM][OAC])为基准,通过分别在阴阳离子上修饰胺基(-NH₂)、羟基(-OH)、腈基(-CN)、卤素(Br、F)等,虚拟设计了15 种阳离子和21 种阴离子组成的离子液体(IL)。采用基于COSMO-RS 模型的COSMOthermX 软件计算了所设计的离子液体对乙腈-水混合物恒压汽液相平衡的影响,探索了修饰基团的种类、离子液体结构对乙腈相对挥发度的影响规律。研究发现,在阳离子碳链上修饰-NH₂,阴离子(醋酸根和丙酸根)羰基的邻碳上进行单一的-OH 修饰能促进乙腈与水的分离,且阳离子修饰的-NH₂ 数越多,促进分离的效果越明显,其他嫁接方式未取得好的分离效果。虚拟设计的两种阳离子(1-胺乙基-3-甲基咪唑、2,2,2-三胺乙基-3-甲基咪唑)与3 种阴离子(羟基乙酸、2-羟基丙酸、2-羟基-3-胺基丙酸)组合的离子液体分离效果明显比[EMIM][OAC]好。     

用于脱除酸性气体的离子液体型吸收剂研究进展

介绍了近年来针对二氧化碳、二氧化硫等酸性气体脱除领域的离子液体型吸收剂的研究进展,阐述了这些离子液体型吸收剂吸收酸性气体不同的机理,评价了常规离子液体、功能化离子液体和离子液体型聚合物等吸收剂的优缺点,对离子液体型吸收剂用于实际应用尚存在的问题提出了建议,并对其发展前景进行了展望.     

磷酸基咪唑离子液体脱除煤焦油柴油馏分中的氮化物

研究了不同磷酸基咪唑离子液体对煤焦油柴油馏分中氮化物的脱除效果.分别以磷酸酯和磷酸二氢根为阴离子合成了烷基碳链长度不同的咪唑磷酸酯和咪唑磷酸二氢盐离子液体,考察了不同条件下离子液体对煤焦油柴油馏分的脱氮效果.结果表明,酸性咪唑磷酸二氢盐离子液体脱氮效果优于咪唑磷酸酯离子液体,1-丁基-3-甲基咪唑磷酸二氢盐([BMim]H₂PO₄)离子液体的脱氮效果最佳.在剂油质量比为0.2、反应温度为40℃、反应时间和静置时间均为30min的条件下,[BMim]H₂PO₄对煤焦油柴油馏分的脱氮率为92.3%,循环使用5次后仍具有稳定的脱氮效果.     

离子液体吸收分离一氧化碳的研究进展

离子液体(ILs)作为一种新型的绿色溶剂在吸收和分离一氧化碳(CO)方面显示出了独特的优异性和潜在的应用价值。对近年来ILs参与CO吸收分离的研究工作进展进行了综述,主要包括常规ILs、阴离子功能化ILs、ILs/Cu (Ⅰ)盐和ILs支撑液膜。重点论述了CO在ILs中的溶解度及对其他气体的选择性,并与ILs吸收分离二氧化碳(CO₂)性能进行了比较;着重讨论了阴阳离子种类、取代基类型、温度、压力等因素对ILs吸收分离CO性能的影响,并介绍了ILs吸收CO的机理。最后,对设计合成新型功能化ILs应用于高效吸收分离CO提出了一些建议。     

离子液体吸收分离硫化氢进展

针对近年来离子液体在吸收分离硫化氢(H₂S)气体方面的研究进展, 重点论述了H₂S在离子液体中的溶解度及对其他气体的选择性、H₂S-离子液体体系的热力学性质及模型。对离子液体吸收H₂S的机理进行了分析, 阐述了离子液体阴阳离子种类、结构以及取代基等对H₂S分离性能的影响规律, 简要提出了该领域存在的研究难点和未来的发展方向。     

COSMO-RS based predictions for the desulphurization of diesel oil using ionic liquids: Effect of cation and anion combination

Ionic Liquids ILs provide an important alternative in removing aromatic sulphur compounds by Liquid-Liquid Extraction (LLE). A total of 28 anions and 6 cations resulting in 168 possible combinations were screened via COSMO-RS (COnductor Like Screening MOdel for Real Solvents). Initially benchmarking was performed to predict the infinite dilution activity coefficients of thiophene in ionic liquids. Comparison with literature values involving 8 ILs with 20 points gave the average root mean square deviation (RMS) to be 11%. Thereafter artificial simulated diesel, aromatic sulphur compound and the cation and anion combination was used to predict the capacity (C) and selectivity (S) at infinite dilution. In general the selectivities were found to decrease in the following order: thiophene (4-24) > benzothiophene (2-12)> dibenzothiophene (1-7). The different hetero atom (N,S,O) and its location in the cation structure strongly influenced the selectivity and capacity at infinite dilution for all the three aromatic sulphur compounds. It was found that the cation without the aromatic ring combined with anions having sterical shielding effect such as [SCN], [CH₃SO₃], [CH₃COO], [Cl], and [Br] proved to be the most favourable IL for desulphurization. [EMMOR][SCN] proved to be the most viable IL for the removal of all the three aromatic sulphur compounds.     

Effect of water on extractive desulfurization of fuel oils using ionic liquids:A COSMO-RS and experimental study

When evaluating ionic liquids(ILs) for extractive desulfurization(EDS) of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work,COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H_2 O mixtures,which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C_4MIM][H_2PO_4], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the crosssolubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range(b 10 wt%) was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent–solute interactions and the COSMO-RS based analysis.     

离子液体气体干燥技术的研究进展

离子液体（ionic liquids, ILs）被视为化工中传统溶剂的优良替代物,使用它们作为溶剂吸收可凝性气体时,具有溶剂损失少、无腐蚀和稳定性强等优点。一些ILs具有很强的吸水性,所以在气体干燥领域ILs受到了广泛关注。本文介绍了用于预测气体在ILs中溶解度的预测型分子热力学模型和气体在ILs中的实验测量方法,具体分析了ILs对CH₄、CO₂等气体的干燥机理和工艺,最后对ILs用于气体干燥的基础研究作出展望。     

COSMO-RS:An ionic liquid prescreening tool for gas hydrate mitigation

Recently ionic liquids(ILs) are introduced as novel dual function gas hydrate inhibitors. However, no desired gas hydrate inhibition has been reported due to poor IL selection and/or tuning method. Trial error as well as selection based on existing literature are the methods currently employed for selecting and/or tuning ILs. These methods are probabilistic, time consuming, expensive and may not result in selecting high performance ILs for gas hydrate mitigation. In this work, COSMO-RS is considered as a prescreening tool of ILs for gas hydrate mitigation by predicting the hydrogen bonding energies(E_(HB)) of studied IL inhibitors and comparing the predicted E_(HB) to the depression temperature(?) and induction time. Results show that, predicted EHBand chain length of ILs strongly relate and significantly affect the gas hydrate inhibition depression temperature but correlate moderately(R = 0.70) with average induction time in literature. It is deduced from the results that, ? increases with increasing IL EHBand/or decreases with increasing chain length. However, the cation–anion pairing of ILs also affects IL gas hydrate inhibition performance. Furthermore, a visual and better understanding of IL/water behavior for gas hydrate inhibition in terms of hydrogen bond donor and acceptor interaction analysis is also presented by determining the sigma profile and sigma potential of studied IL cations and anions used for gas hydrate mitigation for easy IL selection.