固载氨基化离子液体的制备及其对CO2的吸附性能

利用浸渍法将[NH₃P-mim][BF₄]和[MEA]L两种离子液体负载到AC、Al₂O₃和MCM-41上,考察了对CO₂的吸附性能,确定了[NH₃P-mim][BF₄]/AC对CO₂的吸附性能最优。并对[NH₃P-mim][BF₄]/AC考察了不同负载量、不同温度下对CO₂的吸附性能,确定了固载离子液体对CO₂的吸附容量随着负载量的增加而增加,且30℃是固载离子液体吸附CO₂的最佳温度,吸附容量达到0.063 mmol CO₂·(g SILP)^-1。对[NH₃P-mim][BF₄]/AC进行红外和热重两种表征,确定了负载离子液体的结构以及在50℃以下优良的热稳定性。     

咪唑类离子液体对木质纤维预水解液的脱毒

针对燃料乙醇生物炼制过程中抑制物对酵母乙醇发酵的抑制作用,以水洗稀酸蒸汽爆破预处理玉米秸秆得到的预水解液为研究对象,采用新型绿色脱毒技术--离子液体进行萃取脱毒,研究比较了两种咪唑类离子液体[烷基咪唑六氟磷酸盐离子液体[C_nmim][PF₆](n 4,6,8)和烷基咪唑四氟硼酸盐离子液体[C_nmim][BF₄](n 6,8)]对预水解液的萃取性能。结果表明,随着咪唑类离子液体阳离子烷基链长度的增加,离子液体对抑制物的萃取性能下降,具有更强电负性的阴离子为BF₄^-的离子液体比阴离子为PF₆^-的离子液体萃取效率更高。通过比较糖与抑制物的萃取率,最终选择[C₈mim][BF₄]作为预水解液的萃取剂,结果显示其对主要抑制物甲酸、乙酸、5-羟甲基糠醛的萃取率分别为53.22%、47.53%和85.13%,总酚的萃取率为65.05%,而糖的损失率在6%以内。     

离子液体协同PVCap抑制天然气水合物生成实验研究

利用自制的高压反应釜实验研究了离子液体N-丁基-N-甲基吡咯烷四氟硼酸盐([BMP][BF₄])、动力学抑制剂聚乙烯己内酰胺(PVCap)及其二元复合物对CH₄/C₂H₆/C₃H₈混合气体水合物生成动力学的影响，发现在任何浓度下(0.25%～2.0%，质量分数)，[BMP][BF₄]对混合气体水合物抑制能力远弱于PVCap，但对PVCap具有显著协同效应，且随着PVCap占比增大而增强。粉末X射线衍射(PXRD)和低温激光拉曼光谱测试结果证实，所有体系中形成的样品中均含sⅡ型和sⅠ型两种结构水合物，含PVCap体系中sⅡ/sⅠ水合物相对含量降低。低温冷冻电镜(Cryo-SEM)观测结果显示，添加单一PVCap及其与[BMP][BF₄]的混合物会使水合物晶体的微观形貌更粗糙且多孔。     

[Bmim][BF4]/MEA混合水溶液吸收CO2的吸收性能与液液分相机理

对液液两相CO₂吸收剂1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim][BF₄]）/乙醇胺（MEA）混合水溶液吸收性能进行了实验测定,研究了离子液体[Bmim][BF₄]的引入对吸收性能和液液分相的影响,并通过定量碳谱核磁共振法对分相机理和各相中的物质分布进行分析。研究结果表明,一定配比的[Bmim][BF₄]/MEA混合水溶液吸收CO₂之后会出现互不相溶的液液两相,这种现象伴随着CO₂产物的富集;导致液液分相的原因是氨基甲酸盐浓度的增大;随着[Bmim][BF₄]质量分数的增大,溶液吸收速率呈现出先增大后减小的趋势;分层后H₂O主要分布在富液相,[Bmim][BF₄]主要分布在贫液相,H₂O的质量分数直接影响分层后富液相的传质性能。     

离子液体/低共熔溶剂用于NH3分离过程的热力学分析

氨气（NH₃）作为一种有害气体,其传统吸收技术存在诸多缺陷,亟需开发性能优越的NH₃吸收剂,以开发新型NH₃分离技术。离子液体和低共熔溶剂作为气体分离过程的潜在吸收剂,因低挥发性、良好的热稳定性以及灵活的可调控性等特点受到越来越多的关注。但离子液体和低共熔溶剂数量众多,筛选困难。采用热力学分析方法分析离子液体和低共熔溶剂用于NH₃分离过程,基于Gibbs自由能变,拟合出分离过程的最佳操作条件,将总能耗和离子液体用量作为筛选标准,筛选出性能良好的[Omim][BF₄]。将[Omim][BF₄]与传统NH₃吸收剂水对比,发现[Omim][BF₄]具有更低的能耗。最后,拟合出筛选标准与离子液体/低共熔溶剂的临界性质间的规律,为开发新的NH₃吸收剂和新的分离技术提供依据。     

离子液体体系用于盐湖卤水提取锂

3种咪唑类离子液体:1-丁基-3-甲基咪唑六氟磷酸盐([C₄mim][PF₆])、1-己基-3-甲基咪唑六氟磷酸盐([C₆mim][PF₆])、1-辛基-3-甲基咪唑六氟磷酸盐([C₈mim][PF₆])被作为绿色溶剂用于盐湖卤水分离镁锂, 建立了以离子液体(ILs)、磷酸三丁酯(TBP)分别为萃取介质和萃取剂的盐湖卤水锂萃取体系, 并与使用传统有机溶剂磺化煤油和氯仿的萃取效果进行了对比。研究发现, 该离子液体体系较使用传统挥发性有机溶剂的萃取体系有更高的萃取率。锂的萃取率随离子液体中烷基碳原子数的减小而增加。详细考察了溶液pH、离子液体浓度、相比对萃取效率的影响, 获得了离子液体体系萃取的最优条件。在最佳萃取条件下, 3种离子液体体系对锂的单级萃取效率均高于80%, 分离系数最高达到100以上。机理研究表明:离子液体体系是以阳离子交换实现对锂的萃取, Li⁺与TBP形成[Li·2TBP]⁺络合物进入有机相。     

Electrical conductivities for four ternary electrolyte aqueous solutions with one or two ionic liquid components at ambient temperatures and pressure

Thiswork provides amethod to explore the transport property of the electrolyte aqueous solutionswith one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems NaCl–[C₆mim][Cl] (1-hexyl-3-methylimidazolium chloride)–H₂O, [C₆mim][BF₄]–[C₆mim][Cl]–H₂O, NaNO₃–[C₆mim][BF₄](1-hexyl-3-methylimidazolium tetrafluoroborate)–H₂O, and [C₄mim][BF₄] (1-butyl-3- methylimidazolium tetrafluoroborate)–[C₆mim][BF₄]–H₂O, and their binary subsystems NaNO₃–H₂O, NaCl–H₂O, [C₆mim][BF₄]–H₂O, [C₆mim][Cl]–H₂O, and [C₄mim][BF₄]–H₂O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.     

2,6-二甲氧基苯酚在1-丁基-3-甲基咪唑四氟硼酸盐水溶液中溶解行为的红外光谱分析

利用衰减全反射红外光谱(ATR-IR)和二维相关红外技术研究2, 6-二甲氧基苯酚(2, 6-DMP)在1-丁基-3-甲基咪唑四氟硼酸盐([C₄mim]BF₄)水溶液(离子液体摩尔分数x_IL=1.0～0.02)中的溶解行为。随着水量增大, 2, 6-DMP溶解度先增大而后急剧减小, 对应的x_IL阈值为0.1。2, 6-DMP与[C₄mim]BF₄之间存在强相互作用, 2, 6-DMP上的甲氧基是重要作用位点之一;当少量的水加入[C₄mim]BF₄(x_IL=0.1～1.0), 致密的离子簇结构被解离, 2, 6-DMP容易与[C₄mim]BF₄作用, 溶解度增大;随着大量水加入(0.02IL<0.1), 离子簇完全解离为大分子水簇包围的离子对, 憎水的2, 6-DMP与[C₄mim]BF₄作用困难, 溶解度减小。这种由于水量改变引起的[C₄mim]BF₄水溶液微观结构变化影响2, 6-DMP溶解行为。     

功能型离子液体的合成表征及CO2吸收性能

合成了两种传统型离子液体［bmim］BF₄和［emim］BF₄及含有胺基和羟基的功能型离子液体［NH₂P-mim］Br、［NH₂-e-mim］BF₄、［OH-e-mim］Br,并对合成的离子液体进行IR和¹H NMR表征。常温常压条件下,对所合成的离子液体开展CO₂吸收性能实验,发现胺基改性离子液体［NH₂P-mim］Br、［NH₂-e-mim］BF₄和羟基改性离子液体［OH-e-mim］Br的CO₂饱和吸收量分别是常规离子液体的3～9倍和1～2倍,且含有乙基官能团的离子液体吸收平衡时间普遍较短。最终探讨了温度、CO₂分压等对功能型离子液体吸收CO₂过程的影响。     

以离子液体为吸收剂的吸收式制冷循环热力学分析

分析了R161/[hmim][Tf₂N]、R32/[emim][Tf₂N]、R290/[emim][BF₄]三种工质对的热力学性能;采用NRTL模型对制冷剂/离子液体的汽液相平衡数据进行了关联;探讨了发生器出口温度、蒸发器出口温度及吸收温度对循环比、COP及?效率的影响。R32/[emim][Tf₂N]和R161/[hmim][Tf₂N]的COP相近,R290/[emim][BF₄]的COP最小;在蒸发温度、吸收温度分别是5、25℃时,R32/[emim][Tf₂N]系统的COP随着发生温度的变化可达到0.59以上,R290/[emim][BF₄]的COP低于0.1;降低吸收温度可以扩大循环的可行温度,提高COP;蒸发温度为5℃,吸收温度从30℃降低到25℃,COP可提高1.4倍以上。     

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 ...     

Determination and Correlation of Solubilities of Four Novel Benzothiazolium Ionic Liquids with PF6^- in Six Alcohols

Four novel benzothiazolium ionic liquids with 6PF- （[C1Bth][PF6], [C4Bth][PF6], [C5Bth][PF6] and [C6Bth][PF6]） were synthesized, and the rang of their melting points were determined between 358.35 K-424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected‘S’ type ten-dency. Then, the solubilities of the four ionic liquids in six lower alcohols （methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol） were measured in the temperature rang of 253.15-383.15 K at at-mospheric pressure with static analytical method, respectively. It was found that [C6Bth][PF6] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C4Bth][PF6] in methanol was very sensi-tive for temperature in 313.15-333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids （ILs） become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation andλh equation, respectively. It was found that the result of correlation using two divided tem-perature ranges was better than that of using the whole temperature range.     

低黏二氰胺类离子液体乙烯汽液相平衡研究

从工业废气中回收分离乙烯（C₂H₄）具有重要意义,选用了三种低黏度二氰胺类离子液体,分别测定了293.15~333.15 K下其密度、黏度等物化性质,研究了其对乙烯（C₂H₄）吸收性能。采用非随机（局部）双液体模型（NRTL）关联了三种二元体系溶解度数据,实验值与计算值的平均相对偏差均小于3%。结果表明,低黏度二氰胺类离子液体对C₂H₄气体吸收性能良好,其中阳离子侧链长度增加和羟基功能团引入可增强对C₂H₄溶解度。同时,离子液体1-丁基-3-甲基咪唑二氰胺盐（[Bmim][DCN]）经过3次的吸收解吸循环,仍可以保持较好的C₂H₄吸收性能,表明该离子液体循环稳定性好,而1-丁基-3-甲基咪唑二氰胺盐（[Bmim][DCN]）对乙烯吸收量较高,具有作为C₂H₄吸收剂的潜力。     

丁二烯抽提工艺中离子液体添加剂的筛选及分离性能

提出以离子液体为第三组分的丁二烯抽提新工艺,通过考察不同结构的离子液体对C₄组分在复合萃取剂中相对挥发度的影响,并结合量化计算的方法,研究了该工艺中萃取剂和第三组分与C₄组分的相互作用机理,从而优选出适用于该工艺的离子液体添加剂[Emim][PF₆]。另外研究了该离子液体在工业条件下对C₄组分分离性能的影响,并对改进前后的工艺进行全流程模拟计算。结果表明：与现有乙腈法相比,离子液体的加入有利于提高C₄在新型萃取剂中的相对挥发度,具有很好的分离效果。含离子液体的新工艺可使能耗降低约6.62%,乙腈消耗量降低约24%,而且离子液体能够回收利用,回收率高达98%（质量分数）以上,因此基于离子液体的乙腈法抽提丁二烯新技术具有很好的工业应用前景。     

离子液体支撑液膜的CO2/CH4分离性能

由于离子液体对CO₂具有较好的溶解选择性,离子液体支撑液膜分离CO₂越来越受到关注。比较了含3种不同阴离子的常规离子液体([bmim][BF₄]、[bmim][PF₆]、[bmim][Tf₂N])作为支撑液膜的液膜相分离CO₂/CH₄的性能,考察了咪唑环上烷基链长对离子液体支撑液膜性能的影响。考虑向离子液体中引入胺基和羧基等亲CO₂基团,制备了1-丁基-3-甲基咪唑丙氨酸离子液体([bmim][β-Ala]),考察了 [bmim][β-Ala]支撑液膜分离CO₂/CH₄的性能,并对在CO₂渗透测试前后的支撑液膜进行了FT-IR分析,发现氨基酸离子液体中的-NH₂和CO₂的较强作用以及该离子液体的高黏性影响了CO₂的透过性,使[Bmim][β-Ala]支撑液膜的CO₂透过率低。     

SEPARATION OF AROMATIC AND ALIPHATIC HYDROCARBONS WITH IONIC LIQUIDS

Naphtha cracker feeds may contain 10-25 wt% aromatic compounds. Removal of these aromatic compounds from the feed to the cracker would offer several advantages: higher capacity, higher thermal efficiency, and less coke formation. In this work, we investigated the separation of toluene from heptane by extraction with ionic liquids.

Several ionic liquids are suitable for extraction of toluene from toluene/heptane mixtures. The selectivities for the aromatic/aliphatic hydrocarbon separation with all ionic liquids tested increase with decreasing aromatic content in the feed. The toluene/heptane selectivities at 10% toluene in the feed at T = 40°C and 75°C with several ionic liquids ([emim]HSO₄, [mmim] methylsulfate, [emim] ethylsulfate, [bmim]BF₄, [emim] tosylate, [mebupy]BF₄, and [mebupy] methylsulfate) are a factor of 1.5-2.5 higher than those obtained with sulfolane, which is a conventional solvent for the extraction of aromatic hydrocarbons from a mixed aromatic/aliphatic hydrocarbon stream. The three most suitable ionic liquids from the ionic liquids tested for the separation of aromatic and aliphatic hydrocarbons are [mebupy]BF₄, [mebupy]CH₃SO₄, and [bmim]BF₄ and at 75°C also [emim] tosylate. The ionic liquid [mebupy]BF₄ is selected for further testing in our extraction pilot plant.

Because ionic liquids have a negligible vapor pressure, evaporating the extracted hydrocarbons from the ionic liquid phase could achieve the recovery of the ionic liquid. A conceptual process scheme for the extraction has been set up. Preliminary calculations show that both the investment costs and the energy costs will be considerably lower with ionic liquids than with sulfolane as the solvent.