离子液体中结晶分离熊果酸和齐墩果酸研究

为拓展结晶溶剂的范围和提高结晶分离熊果酸和齐墩果酸的性能,引入离子液体作为结晶溶剂。测定了熊果酸和齐墩果酸在六种离子液体+乙醇溶液中的溶解度数据,根据该数据,选取1-辛基-3-甲基咪唑六氟磷酸+乙醇混合溶液作为溶剂对熊果酸和齐墩果酸进行了结晶分离,并采用单因素实验对结晶工艺进行了初步优化。结果表明:在1-辛基-3-甲基咪唑六氟磷酸质量分数5%,熊果酸和齐墩果酸质量比1.5∶1,结晶温度30℃,结晶时间14 h的条件下,结晶产物中齐墩果酸的质量分数可以达到85%左右。     

离子液体作为CO_2吸附剂的研究进展

离子液体(ILs)是完全由特定阳、阴离子构成的在室温或近于室温下呈液态的物质,是一类新型"软"功能材料或介质,CO2能与ILs发生强相互作用,在其中具有很高的溶解度。本文综述了CO2在传统离子液体、功能化离子液体、聚合离子液体及其他形式离子液体中的溶解度,讨论了CO2在离子液体中溶解度的影响因素以及计算机模拟在离子液体溶解CO2研究中的应用,指出了离子液体作为吸收剂的优缺点,展望了其代替传统CO2吸收剂的研究前景。     

An ionic liquid proposed as solvent in aromatic hydrocarbon separation by liquid extraction

Liquid–liquid extraction is the most common method for extraction of aromatics from their mixtures with aliphatic hydrocarbons. An ionic liquid (IL) 1‐butyl‐1‐methylpyrrolidinium bis (trifluoromethylsulfonyl) imide [BMpyr][NTf₂] was tested as solvent for this separation. The liquid–liquid equilibria (LLE) of the ternary mixtures heptane + benzene, or toluene, or ethylbenzene + [BMpyr][NTf₂] were carried out at 298.15 K. The solvent ability of the IL was evaluated in terms of solute distribution ratio and selectivity. The results were compared with those previously reported for the extraction of aromatics from its mixtures with heptane by using ILs. The conventional process using sulfolane as solvent was discussed. The experimental LLE data were correlated by non‐random two liquid equation. A proposal of extraction process with this IL as solvent is simulated by conventional software and the results are shown. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

环境化工中的气/液膜接触分离过程及其特性

阐述了新型膜接触器由于避免了传统分离设备的一系列缺点和不足,具有操作范围宽,分离效率高,气液两相的流速可独立控制,可直接线性放大和结构紧凑等众多优点,日益成为分离科学研究的热点。并着眼于3种气/液界面膜接触分离过程(膜吸收、膜蒸馏、膜结构填料替代)在废气、废水等环境治理与化工分离方面的研究,从膜接触器结构、膜材料、传质、分离效率等方面详细分析和探讨了三种膜过程的分离特点,并对其作用原理、操作参数及分离性能进行了综合比较。     

胶体泡沫和双液泡沫体系及其在分离中的应用

胶体泡沫(CGA)和双液泡沫(CLA)作为一类新的多相分散体系,其特点是包封的皂膜较厚,皂膜内外都存在表面活性剂单分子层,与普通泡沫有很大不同,如泡径小(微米级)、稳定性高、比表面大等,其应用也日益受到关注。概述了CGA和CLA的结构、性质、表征方法、手段和研究进展以及在离子浮选、除油、萃取、蛋白质分离等过程中的应用。     

Mixed gas and pure gas transport properties of copolyimide membranes

Copolyimides were synthesized from dianhydride of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with various diamine contents of 4,4′‐oxydianiline (ODA) and 2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (TeMPD) by chemical imidization in a two‐step procedure. Polyimides (PIs) were characterized using thermogravimetric analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, as well as specific volume and free volume. The gas transport properties for pure gas and blends of CO₂ and CH₄ for the homopolymers and 6FDA‐ODA/TeMPD copolymers were investigated at 35°C and 150 psi pressure. In pure gas permeation, permeability of CO₂ and CH₄ increased with increasing TeMPD content in the diamine moiety, whereas the ideal selectivity decreased with increasing TeMPD content. In the mixed gas permeation, permeabilities and separation factor were measured as a function of CO₂ feed molar fraction for five PI membranes. The behavior of pure gas and mixed gas permeabilities and separation factor of CO₂/CH₄ mixtures as the chemical nature of the diamine and the CO₂ molar fraction in the feed gas were varied and are discussed in detail. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

CO2萃取分离离子液体［bmim］［PF6］与萘的高压相平衡

采用紫外光谱在线检测的静态相平衡方法,在温度313～333 K、压力8～20 MPa、萘的液相浓度0.0169～0.378 mol·kg^-1的范围内,测定了CO₂+［bmim］［PF₆］+萘三元系中萘在富含CO₂相的浓度。结果表明,在所测温度和压力范围内,萘在富含CO₂相的浓度随着温度的升高而减小,随着压力的升高而增大,而且随着萘在液相中的浓度的减小而减小。在一定的温度压力条件下,萘在富含CO₂相的浓度与萘在液相中的浓度近似呈双对数线性关系。采用Chrastil缔合模型关联了所有溶解度数据,平均相对偏差为14.9 %。此外,还探讨了CO₂萃取分离离子液体与高沸点有机物的操作模式,发现釜式间歇操作较为适宜。     

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。     

气体膜分离混合气中二氧化碳的研究进展

气体膜分离技术作为碳捕获方案被国际社会认为是最有发展潜力的脱碳方法之一.综述介绍了中空纤维膜接触器、膜结构、系统工艺和吸收剂的研究现状.相对于水和碳酸盐类,醇胺具有的二氧化碳吸收率高、反应热低、反应速度快以及容易再生等优点,在研究与工业过程中是应用最广泛的吸收剂之一.     

An ionic liquid reaction and separation process for production of hydroxymethylfurfural from sugars

Hydroxymethylfurfural (HMF) is viewed as a potential platform material to make a variety of chemicals and products out of renewable resources. In this work, a complete ionic liquid reaction and separation process is presented for nearly stoichiometric conversion of fructose into HMF. The silicalite adsorbent material is demonstrated for separation of 99% pure HMF out of ionic liquid reaction mixtures through a packed column and for recovery of the unconverted sugars and reaction intermediates along with the ionic liquid. Membrane‐coated silicalite particles are prepared and studied for a practical adsorption process with separation performances comparable to or better than the powder material. It is discovered that nearly all the fresh fructose feed could be converted into HMF with the recycled ionic liquid under suitable reaction conditions. These research results lead to a new HMF production process much simpler than the current paraxylene manufacturing process from petroleum oil. © 2013 American Institute of Chemical Engineers AIChE J, 60: 300–314, 2014     

Effect of solvent evaporation conditions on gas separation performance for asymmetric polysulfone membranes

Asymmetric polysulfone membranes were prepared by the phase inversion technique under different solvent evaporation conditions prior to the gelation step. The membranes were cast from the two component system of polymer and N,N‐dimethylacetamide in which the polymer concentration was changed from 25.0 to 30.0%. The solvent evaporation temperature was changed from 70 to 120°C, and the evaporation time was 0–15 min. Ethanol, water, or 2‐propanol was used as the gelation media. The membranes were characterized by the measurement of oxygen/nitrogen permeation with the lamination technique and by observation with scanning electron microscopy. With an increase in the solvent evaporation time, the oxygen permeance decreased and its selectivity over nitrogen increased; although the permeance was in the range of 1–2 GPU, the oxygen selectivity over nitrogen exceeded 8. A correlation between the permeation performance and the operational parameters involved in the solvent evaporation process was obtained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1367–1374, 1999     

催化裂化干气分离丙烯用活性炭吸附剂的特性研究

为了获得可用于催化裂化干气中吸附分离丙烯用的活性炭,选择国内有代表性的不同材质和产地的活性炭,测定了比表面积、孔容、平均孔径和微孔体积等物性参数.在自制的吸附实验装置上,测定了101.3 kPa、40℃下丙烯和乙烯在不同活性炭上的吸附量,比较对丙烯的选择性.结果表明在上述吸附条件下,活性炭AC-1对丙烯的吸附量最大,达3.552 mmol/g,对丙烯的选掸性为1.37.测定了乙烯丙烯二元混合气中,不同丙烯分压下,活性炭AC-1对丙烯和乙烯的吸附量.活性炭AC-1适用于干气吸附分离丙烯过程.     

离子液体在膜分离过程中的应用研究进展

介绍了离子液体(ionic liquids)是由有机阳离子和有机或无机阴离子构成的、在室温或室温附近温度下呈液体状态的盐类,是新兴的可替代挥发性有机化合物的绿色溶剂。阐述了离子液体具有熔点低、不易燃、低挥发性(蒸气压接近于零)、高导电能力、电化学窗口宽、可调节性强等独特性质;在二氧化碳、二氧化硫等酸性气体以及苯、环己烷等有机溶剂分离过程中有广泛应用前景。同时,介绍了含有双键等可聚合基团的一类离子液体-聚离子液体[poly(ionic liquid)s,PILs]在二氧化碳吸收方面有特殊表现,指出聚离子液体与聚偏氟乙烯(PVDF)共混得到的薄膜材料具有高稳定性、高机械强度以及高电导率,对于缓解能源匮乏以及环境污染等具有重大意义。     

New high permeable polysulfone/ionic liquid membrane for gas separation

In this study, the effects of 1-Ethyl-3-methylimidazolium tetrafluoroborate ionic liquid on CO₂/CH₄ separation performance of symmetric polysulfone membranes are investigated. Pure polysulfone membrane and ionic liquid-containing membranes are characterized. Field emission scanning electron microscopy (FE-SEM) is used to analyze surface morphology and thickness of the fabricated membranes. Energy dispersive spectroscopy (EDS) and elemental mapping, Fourier transform infrared (FTIR), thermal gravimetric (TGA), X-ray diffraction (XRD) and Tensile strength analyses are also conducted to characterize the prepared membranes. CO₂/CH₄ separation performance of the membranes are measured twice at 0.3 MPa and room temperature (25 °C). Permeability measurements confirm that increasing ionic liquid content in polymer-ionic liquid membranes leads to a growth in CO₂ permeation and CO₂/CH₄ selectivity due to high affinity of the ionic liquid to carbon dioxide. CO₂ permeation significantly increases from 4.3 Barrer (1 Barrer=10^-10 cm³(STP)·cm·cm^-2·s^-1·cmHg^-1, 1cmHg=1.333kPa) for the pure polymer membrane to 601.9 Barrer for the 30 wt% ionic liquid membrane. Also, selectivity of this membrane is improved from 8.2 to 25.8. mixed gas tests are implemented to investigate gases interaction. The results showed, the disruptive effect of CH₄ molecules for CO₂ permeation lead to selectivity decrement compare to pure gas test. The fabricated membranes with high ionic liquid content in this study are promising materials for industrial CO₂/CH₄ separation membranes.     

负载离子液体的阳离子交换膜在烯烃/烷烃分离中的应用

制备了负载胆碱赖氨酸盐离子液体（[Ch][Lys]）的阳离子交换膜,测定并表征其膜的性能,研究其在电渗析下分离1-己烯/n-己烷的能力。结果表明,膜含水率和离子交换容量随离子交换树脂质量分数和离子液体含量的增加而增大;膜的面电阻随树脂质量分数增大而减小,随离子液体含量的增大而增大;膜中添加离子液体明显提高了其分离1-己烯/n-己烷的能力,当阳离子交换树脂含量为70%、离子液体添加量为15%时,所制的阳离子交换膜对1-己烯分离的选择性最高,其值可达9.5。     

提高UDS溶剂脱除塔河油田伴生天然气中有机硫效率

为了解决新疆塔河油田伴生天然气中高含量有机硫的脱除难题,需开发高效脱硫溶剂。基于已在天然气净化领域工业应用的UDS-2溶剂的初始组成,采用量子化学计算并结合溶解度COSMO-RS模型预测优选提高甲硫醇(MeSH)溶解性能的溶剂组分,改进原UDS-2溶剂对MeSH的脱除性能,并分别在常压和高压吸收实验装置上对比考察不同溶剂对模拟塔河油田伴生天然气的吸收净化效果。结果表明,聚合度为5的聚乙二醇二甲醚（PEGDME-3）与MeSH分子之间的相互作用最强,对MeSH的溶解性能最好,相同条件下,MeSH在PEGDME-3中的亨利系数最小,40℃时的亨利系数为14.9 MPa·L/mol。PEGDME-3调配入原UDS-2溶剂中获得的改进UDS溶剂,对MeSH和总有机硫的脱除率较改进前原UDS-2溶剂分别提高了10.1%～11.4%和7.2%～8.5%。所得结论将有助于进一步提高UDS溶剂的有机硫脱除效率,满足塔河油田伴生天然气高含量有机硫的脱除净化需求。     

Development of ethanolamine‐based ionic liquid membranes for efficient CO2/CH4 separation

This study is focused on the development of ionic liquids (ILs) based polymeric membranes for the separation of carbon dioxide (CO₂) from methane (CH₄). The advantage of ILs in selective CO₂ absorption is that it enhances the CO₂ selective separation for the ionic liquid membranes (ILMs). ILMs are developed and characterized with two different ILs using the solution‐casting method. Three different blend compositions of ILs and polysulfone (PSF) are selected for each ILMs 10, 20, and 30 wt %. Effect of the different types of ILs such as triethanolamine formate (TEAF) and triethanolamine acetate (TEAA) are investigated on PSF‐based ILMs. Field emission scanning electron microscopy analysis of the membranes showed reasonable homogeneity between the ILs and PSF. Thermogravimetric analysis showed that by increasing the ILs loading thermal stability of the membranes improved. Mechanical analysis on developed membranes showed that ILs phase reduced the amount of plastic flow of the PSF phase and therefore, fracture takes place at gradually lower strains with increasing ILs content. Gas permeation evaluation was carried out on the developed membranes for CO₂/CH₄ separation between 2 bar to 10 bar feed pressure. Results showed that CO₂ permeance increases with the addition of ILs 10–30 wt % in ILMs. With 20–30 wt % TEAF‐ILMs and TEAA‐ILMs, the highest selectivity of a CO₂/CH₄ 53.96 ± 0.3, 37.64 ± 0.2 and CO₂ permeance 69.5 ± 0.6, 55.21 ± 0.3 is observed for treated membrane at 2–10 bar. The selectivity using mixed gas test at various CO₂/CH₄ compositions shows consistent results with the ideal gas selectivity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45395.     

Transition between crystallization and microphase separation in PS-b-PEO thin film Influenced by solvent vapor selectivity

In this paper, the effect of solvent selectivity on the transition between crystallization and microphase separation of the semicrystalline diblock copolymer polystyrene-b-poly(ethylene oxide) (PS-b-PEO) thin films was investigated. Square-shaped crystals formed due to lower barrier of crystalline nucleation in both poor and good solvent vapor for PEO. However, in poor solvent (cyclohexane) vapor for PEO, crystalline structure changed to microphase separated structure in the square platelets due to the high mobility of PS blocks. Then breakout crystals dominated the morphology of the film. While, in good solvent (water) vapor for PEO, competition between nucleation and dissolution of crystallization caused the formation of imperfect crystals. Then imperfect crystals dissolved due to the high mobility of PEO blocks, and microphase separation dominated the morphology of the film. The gain of free volume of soluble block and the low swelling of crystalline block are keys for microphase separation and crystallization, respectively.