胆碱脯氨酸/RTILs支撑液膜的CO_2/N_2分离性能

选用不同种类的室温型离子液体(RTILs)与胆碱脯氨酸离子液体进行混合分别制得[Choline][Pro]/[EMIm][N(CN)_2]、[Choline][Pro]/[bmim][PF_6]以及[Choline][Pro]/[HMIm][NTf_2]混合离子液体,并将其应用于离子液体支撑液膜(SILMs)。考察操作温度、操作压差、RTILs种类和含量对SILMs分离CO_2/N_2性能的影响。结果表明胆碱脯氨酸/RTILs系列SILMs的CO_2通量在343.3~1936.9 barrer之间变化并且CO_2/N_2选择性为10.3~34.8。对CO_2膜过程内在机制探索表明随着[HMIm][NTf2]离子液体在混合离子液体中比例的增加,总阻力1/Kμ会呈现先降低后升高的趋势。与实验现象中随着[HMIm][NTf2]离子液体在混合离子液体中比例的增加CO_2先升高后降低相符。     

离子液体[Bmim][NTf2]对CO2在碳酸二乙酯中溶解性能的强化

采用恒定容积法在温度范围308.15~328.15 K、压力范围0~3 MPa条件下测定了CO₂在碳酸二乙酯（DEC）、离子液体[Bmim][NTf₂]以及二者不同质量分数配比混合溶剂中的溶解度,并用COSMO-RS模型研究了离子液体的加入对DEC蒸气分压的影响。实验表明,在相同实验条件下CO₂在[Bmim][NTf₂]中的溶解度大于在DEC中的溶解度。[Bmim][NTf₂]的加入可强化CO₂在DEC中的溶解性能,在相同温度下CO₂在混合溶剂中的溶解度随[Bmim][NTf₂]质量分数增加而增大,在相同浓度的混合溶剂中CO₂的溶解度随温度升高而降低。COSMO-RS模型计算表明,DEC的蒸气分压下降的分数随混合溶剂中离子液体质量分数增加而增大,而对于相同质量分数配比的混合溶剂温度对DEC的蒸气分压影响较小。     

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。     

无水氨基酸类离子液体-聚乙二醇混合溶剂吸收CO2的动力学

以聚乙二醇400（PEG400）为溶剂,氨基酸类离子液体（AAILs）作为化学吸收剂的混合体系具有蒸汽压极低、热稳定性好、黏度和再生能耗低、CO₂吸收量和选择性高等优点,适用于燃烧前CO₂捕集过程的高温高压吸收条件。本文采用压降法,测定了以四正丁基膦（[P₄₄₄₄]⁺）为阳离子,甘氨酸（Gly）、丙氨酸（Ala）和脯氨酸（Pro）作为阴离子的3种氨基酸类离子液体的混合溶剂体系对CO₂的吸收速率,并建立了该无水体系的CO₂吸收动力学模型。对于反应速率而言,在333.15K时,[P₄₄₄₄][Gly]-PEG400 > [P₄₄₄₄][Pro]-PEG400 > [P₄₄₄₄][Ala]-PEG400,温度升高至373.15K时,[P₄₄₄₄][Pro]-PEG400 > [P4444][Gly]-PEG400 > [P₄₄₄₄][Ala]-PEG400;根据相关吸收动力学参数,推测出CO₂在AAILs-PEG400中的反应均为快反应。通过研究其吸收动力学,获得了关键的吸收动力学数据,为后续的工业开发设计提供基础数据和设计依据。     

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。     

超强碱离子液体-有机胺-水复配溶剂高效CO2捕集

CO₂捕集是实现碳减排的重要技术之一。其中，化学吸收法是一种有效的、适用于低CO₂分压的CO₂捕集技术。开发出一种高效、低能耗、环保的吸收剂是该领域的研究难点和热点。离子液体(ILs)作为一类绿色溶剂，在CO₂捕集中具有结构可调节、反应速率快、吸收量高等优势，但存在黏度大、价格昂贵等问题，本工作提出将超强碱离子液体1,8-二氮杂二环[5,4,0]十一碳-7-烯咪唑([HDBU][Im])与单乙醇胺(MEA)复配得到离子液体复配溶剂，来提高吸收剂的CO₂吸收量并降低吸收CO₂后溶剂的黏度。研究了离子液体浓度、吸收温度、CO₂分压等对离子液体复配溶剂捕集CO₂性能的影响，测定了离子液体复配溶剂在不同CO₂负荷下的密度和黏度等物性。结果表明，30wt%MEA+10wt%[HDBU][Im]具有较好的吸收能力，在40℃下，CO₂吸收量达到0.1453 g CO₂     

[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。     

分子筛SBA-15负载离子液体[P66614][Triz]脱除氢烷气中CO2

以高效吸收CO₂的离子液体（IL）[P₆₆₆₁₄][Triz]作为吸收剂,通过浸渍法负载到两种不同孔径的介孔分子筛SBA-15上,用于脱除生物氢烷气中CO₂,并利用N₂吸附仪、扫描电子显微镜（SEM）和高倍透射电子显微镜（HRTEM）对负载材料进行了表征分析。混合吸收剂SBA-15（4.3 nm）-50%[Triz]的吸收容量和吸收速率比SBA-15（6.6 nm）-50%[Triz]的分别提高了12.4%和95.1%,这是由于SBA-15（4.3 nm）的孔道长度更短,避免了填充在孔道内的[P₆₆₆₁₄][Triz]在反应过程中接触不到CO₂,从而比SBA-15（6.6 nm）-50%[Triz]有更多IL反应活性点参与反应。还研究了不同氢烷气速率下SBA-15（4.3 nm）-50%[Triz]对CO₂的吸收并与2种吸附动力学模型相拟合,结果表明SBA-15（4.3 nm）-50%[Triz]对CO₂的吸收更符合准二级吸附动力学模型,表明吸附过程受化学吸附机理的控制,验证了[P₆₆₆₁₄][Triz]是通过化学反应脱除CO₂。     

咪唑类离子液体对苯系挥发性有机物脱除性能的研究

为研究咪唑类离子液体吸收甲苯的性能,考察了甲苯体积分数、吸收温度、N₂进气速度和离子液体流量等对吸收甲苯性能的影响,并评价了离子液体的再生性能。结果表明,[Emim][Tf₂N]、[Bmim][Tf₂N]和[Omim][Tf₂N]这3种离子液体对甲苯的吸收率均在90%以上,且阳离子碳链越长,对甲苯的吸收率越高,3种离子液体对甲苯的吸收率大小为:[Omim][Tf₂N]>[Bmim][Tf₂N]>[Emim][Tf₂N]。甲苯体积分数为3 113μL/L、N₂进气速度为50 mL/min、离子液体流量为15 mL/min和吸收温度为20℃的条件下,离子液体对甲苯的吸收率最高。离子液体在140℃、5 066 Pa下干燥再生5次后性能基本稳定。     

Pebax/a-MoS2/MIP-202混合基质膜的制备及CO2分离性能

为了获得高性能的CO₂/N₂分离膜,把空气中氧刻蚀的二硫化钼（a-MoS₂）和金属有机框架材料MIP-202通过机械力化学反应制备的双功能填料作为分散相,聚醚嵌段酰胺（Pebax-1657）作为连续相,采用溶液浇铸法制备了Pebax/a-MoS₂/MIP-202混合基质膜。采用FT-IR表征了填料的化学结构,借助ATR-FTIR、SEM、TG和力学性能测试表征了混合基质膜的化学结构、微观形貌结构、热稳定性和物理力学性能。研究了水含量、双功能填料配比、含量、膜两侧压差和操作温度对膜气体分离性能的影响,并考察了模拟烟道气（CO₂/N₂体积比15/85）条件下混合基质膜的长时间运行稳定性。结果表明：在温度为25℃、膜两侧压差为0.1 MPa的操作条件下,a-MoS₂与MIP-202质量比为5∶5和双功能填料含量为6%（质量）时,膜的气体分离性能达到最优,CO₂渗透性和CO₂/N₂选择性分别为380 Barrer和124.7,超过了2019年McKeown等提出的上限值。连续测试360 h后,混合基质膜的性能没有明显降低,其平均CO₂渗透性和CO₂/N₂选择性分别为358 Barrer和120.1。这主要是由于a-MoS₂和MIP-202协同提高了膜的气体分离性能。     

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.     

Low-pressure CO2 sorption in ammonium-based poly(ionic liquid)s

Ammonium-based ionic liquid monomers and their corresponding polymers [poly(ionic liquid)s] are synthesized and characterized for CO₂ sorption. The polymers have much higher CO₂ sorption capacities than the room-temperature ionic liquids and imidazolium-based poly(ionic liquid)s. For example, P[VBTMA][PF₆] with polystyrene backbone has a CO₂ sorption capacity of 10.67 mol%. The CO₂ sorption is selective over N₂ and O₂. The effects of cation, backbone, substituent, anion and crosslinking on CO₂ sorption are discussed. The sorption mechanism study indicates that CO₂ sorption by the poly(ionic liquid)s is a bulk and surface phenomenon.     

CO2/N2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.     

肉桂酸型离子液体的合成及其二氧化碳吸收

合成了一系列肉桂酸型功能化离子液体,研究了其CO₂ 吸收性能。结果表明,肉桂酸型功能化离子液体吸收二氧化碳性能良好,其阴离子苯环上的取代基会影响CO₂ 吸收性能。随着温度的升高和压力的降低,其CO₂吸收性能都会降低。同时,该离子液体具有很好的循环稳定性,经过5 次吸收脱附循环,该离子液体仍能保持较高的CO₂ 吸收量。结合红外光谱和其低浓度下CO₂ 的吸收研究发现肉桂酸型离子液体吸收CO₂ 存在着化学作用。     

五种新合成酯基取代的咪唑类离子液体电导率的测定与分析

离子液体的电导率性质反映了离子液体的导电性能,与溶剂中的电离度以及离子的溶剂化能力密切相关。为了研究本实验室合成的5种酯基取代的离子液体的电导率,用DDS307电导率仪测定1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₃]NTf₂)、1-乙酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₂CH₃]NTf₂)、1-乙酸正丙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₂CH₂CH₃]NTf₂)、1-对甲基苯甲酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂C₆H₄COOCH₃]NTf₂)和1-对甲基苯甲酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂C₆H₄COOCH₂CH₃]NTf₂)在二甲基亚砜、甲醇、乙腈和乙酸乙酯中的电导率数据。结果表明,其他条件不变时,在一定浓度范围内,离子液体的电导率随着其浓度的增大而增大;在一定温度范围内,随着温度的升高,离子液体电导率增大;4种溶剂相比电导率从小到大顺序依次为乙酸乙酯、二甲基亚砜、甲醇、乙腈,反映了带酯基的5种离子液体与乙酸乙酯的相互作用。     

New process development and process evaluation for capturing CO2 in flue gas from power plants using ionic liquid [emim][Tf2N]

Using the ionic liquid [emim][Tf_2N] as a physical solvent, it was found by Aspen Plus simulation that it was possible to attempt to capture CO_2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination, the density, isostatic heat capacity,viscosity, vapor pressure, thermal conductivity, surface tension and solubility of [emim][Tf_2N] were obtained.Based on the NRTL model, the Henry coefficient and NRTL binary interaction parameters of CO_2 dissolved in[emim][Tf_2N] were obtained by correlating [emim][Tf_2N] with the gas–liquid equilibrium data of CO_2. Firstly,the calculated relevant data is imported into Aspen Plus, and the whole process model of the ionic liquid absorption process is established. Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process. Finally, the density, constant pressure heat capacity,surface tension, thermal conductivity, and viscosity of [emim][Tf_2N] were changed to investigate the effect of ionic liquid properties on process energy consumption, solvent circulation and heat exchanger design. The results showed that based on the composition of the inlet gas stream to the absorbers, CO_2 with a capture rate of 90% and a mass purity higher than 99.5% was captured. These results indicate that the [emim][Tf_2N] could be used as a physical solvent for CO_2 capture from coal-fired units. In addition, the results will provide a theoretical basis for the design of new ionic liquids for CO_2 capture.