咪唑类三元低共熔溶剂捕集低压SO2的实验研究

近几年来,以氢键受体（HBA）和氢键供体（HBD）组成的低共熔溶剂（DESs）以其类似于离子液体的性质被认为是一种有潜力的SO₂吸附剂。为制备用于低压SO₂吸收的容量大、价格合理、循环性能好的低共熔溶剂,选用咪唑(Im)作为功能化组分,以价格低廉的甘油(Gly)、PEG200和乙二醇(EG)作为第二HBD,与作为HBA的氯化胆碱(CC)构建CC-GIy-Im、CC-PEG200-Im、CC-EG-Im三元功能化低共熔溶剂,并用于低压SO₂的捕集实验研究。着重考察了第二HBD种类、咪唑含量、温度等因素对DESs吸收SO₂的性能影响。结果表明：在所选的第二HBD中,PEG200的性能最佳,其构建的低共熔溶剂密度、黏度适中,热稳定性好,吸收性好;CC-PEG200-Im（1∶2∶7）在40℃下,对1% SO₂的吸收量达到0.236 g SO₂/g DES;经5次吸收-解吸循环后,低共熔溶剂吸收性能仍然稳定;¹H NMR谱图分析结果表明,CC-PEG200-Im对SO₂的吸收机理为化学吸收。     

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。     

吡啶基聚氨酯的制备及其自修复性能研究

为探究氢键对聚氨酯性能的影响,以聚四氢呋喃、异氟尔酮二异氰酸酯、4,4’?二羟基联苯（HBD）和N³,N⁵?双（4?羟基苯基）吡啶?3,5?二甲酰胺（HPD）制备了2种类型的聚氨酯,并利用红外光谱仪（FTIR）、热重分析仪（TG）、万能力学试验机等对2种聚氨酯的化学结构、热稳定性、力学性能和自修复性能等进行了表征和测试。结果表明,2种聚氨酯均表现出了优异的自修复性能;60 ℃下,两者均30 min即可完成自修复;相较于以HBD为扩链剂制备的聚氨酯,以含有吡啶基团和酰胺基团的扩链剂（HPD）制备的聚氨酯表现出更优异的力学性能（拉伸强度为1.2 MPa）、更优异的热稳定性能（热降解活化能为230.3 kJ/mol）及更高的残炭率（800 ℃残炭率约为5 %）。     

磁性离子液体与表面活性剂的相互作用

采用电导法研究了2种季膦盐类磁性离子液体四丁基膦氯合氯化铁盐（[P₄₄₄₄]FeCl₄）和十四烷基三丁基膦氯合氯化铁盐（[P₄₄₄₁₄]FeCl₄）在水溶液与CTAB形成的胶团相互作用和在非水溶液环己烷中与AOT形成的微乳液中相互作用。研究发现：离子液体[P₄₄₄₄]FeCl₄在水溶液和非水溶液中均不和表面活性剂发生作用;[P₄₄₄₁₄]FeCl₄具有长碳链,但其在水溶液和非水溶液中表现出不同于表面活性剂的性质,在水溶液中不与CTAB发生作用,而在AOT/环己烷/水的微乳液体系中,[P₄₄₄₁₄]FeCl₄与AOT在油水界面发生作用,有利于微乳液的形成。     

基于乳酸的深度共熔溶剂提取秸秆木质素对纤维素酶水解效率的影响

基于乳酸的深度共熔溶剂（DES）在脱木素和木质纤维素转化方面显示出巨大潜力。本文以乳酸为氢键供体（HBD）,氯化胆碱、盐酸胍、精氨酸、甜菜碱盐酸盐为氢键受体（HBA）合成了4种DES,并分别提取了木质素,对比研究了4种木质素对微晶纤维素酶水解效率的影响。结果表明,4种DES提取木质素的疏水性与其对酶蛋白吸附能力线性正相关,而两者与木质素与酶水解效率呈线性负相关性。非特异性吸附是该类木质素抑制纤维素酶水解效率最重要的因素,而疏水性作用则是引起酶蛋白吸附的主要原因。结构分析表明木质素的脂肪族羟基和酚羟基主导的氢键相互作用是促进酶蛋白吸附、降低酶水解效率的原因之一。此外,由羧基产生的静电斥力对纤维素酶水解效率的影响较弱。随着DES提取木质素能力的增强,木质素的羟基和羧基含量逐渐增高,其对纤维素酶的抑制作用增大。氯化胆碱-乳酸因其优良的木质素提取和生物质解构能力,提取的木质素对酶的抑制作用最强,其次是乳酸-盐酸胍和乳酸-甜菜碱盐酸盐,最后是乳酸-精氨酸。     

功能型离子液体协同吸收NH3和CO2的密度泛函理论研究

离子液体（ILs）由于其独特的结构可调性,作为添加剂可有效抑制氨法碳捕集中NH₃的逃逸并同时促进CO₂的吸收。揭示其吸收NH₃和CO₂的作用机理对于构建特定的功能型ILs结构具有重要意义。本文采用密度泛函理论（DFT）,在B3LYP/6-31'++G（d,p）基组水平下对设计的五种功能型ILs进行了结构优化、频率计算以及原子电荷分析,获得了优化后的结构参数、振动频率以及原子电荷等数据。在此基础上对ILs吸收CO₂和NH₃进行了相互作用分析。计算结果表明：[HEBim][His]的稳定性最好,经过BSSE校正后的相互作用能为-415.73 kJ·mol^-1。通过静电势和电荷分析找到了设计的ILs与气体作用的最佳位点：NH₃主要与ILs阳离子的羟基形成 O—H…N型氢键,其中,[HEBim][His]吸收NH₃的能力最强,形成的氢键结合能为38.52 kJ·mol^-1,具有较强的氢键作用;CO₂主要与阴离子中的氨基形成C—N…C型氢键,[HEBim][Ala]吸收CO₂的能力最强,形成的氢键结合能为10.15 kJ·mol^-1,具有较弱的氢键作用。当ILs同时与NH₃和CO₂相互作用时,其吸收能力均有不同程度的下降,[HEBim][His]与[HEBim][Ala]的综合吸收效果最佳。     

功能型离子液体协同吸收NH3和CO2的密度泛函理论研究

离子液体（ILs）由于其独特的结构可调性,作为添加剂可有效抑制氨法碳捕集中NH₃的逃逸并同时促进CO₂的吸收。揭示其吸收NH₃和CO₂的作用机理对于构建特定的功能型ILs结构具有重要意义。本文采用密度泛函理论（DFT）,在B3LYP/6-31'++G（d,p）基组水平下对设计的五种功能型ILs进行了结构优化、频率计算以及原子电荷分析,获得了优化后的结构参数、振动频率以及原子电荷等数据。在此基础上对ILs吸收CO₂和NH₃进行了相互作用分析。计算结果表明：[HEBim][His]的稳定性最好,经过BSSE校正后的相互作用能为-415.73 kJ·mol^-1。通过静电势和电荷分析找到了设计的ILs与气体作用的最佳位点：NH₃主要与ILs阳离子的羟基形成 O—H…N型氢键,其中,[HEBim][His]吸收NH₃的能力最强,形成的氢键结合能为38.52 kJ·mol^-1,具有较强的氢键作用;CO₂主要与阴离子中的氨基形成C—N…C型氢键,[HEBim][Ala]吸收CO₂的能力最强,形成的氢键结合能为10.15 kJ·mol^-1,具有较弱的氢键作用。当ILs同时与NH₃和CO₂相互作用时,其吸收能力均有不同程度的下降,[HEBim][His]与[HEBim][Ala]的综合吸收效果最佳。     

离子液体-分子溶剂复合萃取剂脱除水中酚类化合物

构建了疏水性离子液体-分子溶剂复合萃取剂,并研究了其对酚类化合物的萃取性能。结果表明,与纯离子液体萃取剂相比,三己基十四烷基溴化（[P₆₆₆₁₄]Br）-乙酸乙酯复合萃取剂在显著降低萃取剂黏度的同时,获得了较高的酚类溶质分配系数。当萃取剂中[P₆₆₆₁₄]Br摩尔分数为20%时,苯酚的分配系数为345,是纯乙酸乙酯为萃取剂时的5.3倍,是[omim]BF₄、[C₁₂mim]NTf₂等常规疏水离子液体的9~60倍;比纯[P₆₆₆₁₄]Br为萃取剂时的分配系数下降25.3%,黏度却比纯[P₆₆₆₁₄]Br降低99%以上。COSMO-RS研究表明[P₆₆₆₁₄]Br与苯酚之间较强的氢键作用是获得较高苯酚分配系数的关键因素。该复合萃取剂对间苯三酚、4-氯苯酚和2,5-二硝基苯酚等物质也有良好的萃取能力。上述结果为开发兼具良好热力学性能和动力学性能的脱酚萃取剂提供了新的思路。     

含醚阴离子功能化离子液体高效捕集SO2

发展高效、经济、绿色的SO₂吸收剂不但具有较强的学术价值，而且有良好的应用前景。设计并制备了一系列含醚的阴离子功能化离子液体，系统地研究了阴离子上引入醚基团对离子液体SO₂吸收容量的影响。结果表明，在阴离子的苯环上引入甲氧基，对离子液体的吸收容量有明显提升。当阳离子为摩尔质量更小的三丁基乙基磷[P₄₄₄₂]时，所得离子液体的吸收容量没有明显下降，20℃、10⁵ Pa SO₂下，[P₄₄₄₂][2-CH₃OPhCOO]有效吸收量为每摩尔离子液体吸收3.32 mol SO₂，有效质量吸收量是每克离子液体吸收0.56 g SO₂。六次吸收解吸循环，表明[P₄₄₄₂][2-CH₃OPhCOO]可以高效可逆地捕集SO₂。基于含醚阴离子功能化离子液体的加强效应进行气体捕集的方法，可进一步应用于分离、催化等领域。     

络合亚铁乙二醇-四丁基溴化铵低共熔溶剂协同吸收SO2和NO

低共熔溶剂广泛应用于很多领域,尤其在气体净化领域有很好的应用前景。为探究吸收容量大、再生能力较强的低共熔溶剂协同吸收烟气中SO₂和NO的性能,采用氯化亚铁（FeCl₂）、乙二醇（EG）与四丁基溴化铵（TBAB）制备络合亚铁乙二醇-四丁基溴化铵低共熔溶剂［Fe(Ⅱ)EG-TBAB DESs］,重点考察了温度、停留时间、氧气分压和FeCl₂浓度等因素对低共熔溶剂脱除烟气中SO₂和NO性能的影响。结果表明：在温度为50℃、氧气分压为5%、FeCl₂浓度为0.1mol/L的条件下,Fe(Ⅱ) EG-TBAB DESs能够协同高效吸收烟气中的SO₂和NO。烟气中H₂O和O₂存在的条件下,SO₂气体能够形成\mathrm{H}\mathrm{S}{\mathrm{O}}_{\mathrm{3}}^{-}和\mathrm{H}\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{-},进一步促进Fe(Ⅱ) EG-TBAB低共熔溶剂吸收烟气中NO气体,生成Fe(Ⅱ)EG-TBAB(NO)。低共熔溶剂经6次吸收-脱附再生循环后其脱硫脱硝能力变化不大,仍保持较好的脱硫脱硝稳定性。     

Investigation of CO2 solubility in monoethanolamine hydrochloride based deep eutectic solvents and physical properties measurements

Deep eutectic solvents (DESs) have drawn a growing research interest for applications in a wide range of scientific and industrial arenas. However, a limited effort has been reported in the area of gas separation processes and particularly the carbon dioxide capture. This study introduces a novel set of DESs that were prepared by complexing ethylenediamine (EDA), monoethanolamine (MEA), tetraethylenepentamine (TEPA), triethylenetetramine (TETA) and diethylenetriamine (DETA) as hydrogen bond donors to monoethanolamide hydrochloride (EAHC) salt as a hydrogen bond acceptor. The absorption capacity of CO₂ was evaluated by exploiting a method based on measuring the pressure drop during the absorption process. The solubility of different DESs was studied at a temperature of 313.15 K and initial pressure of 0.8 MPa. The DES systems 1EAHC:9DETA, 1EAHC:9TETA and 1EAHC:9TEPA achieved the highest CO₂ solubility of 0.6611, 0.6572 and 0.7017 mol CO₂·(mole DES)^-1 respectively. The results showed that CO₂ solubility in the DESs increased with increasing the molar ratio of hydrogen bond donor. In addition, the CO₂ solubility increased as the number of amine groups in the solvent increases, therefore, increasing the alkyl chain length in the DESs, resulted in increasing the CO₂ solubility. FTIR analysis confirms the DES synthesis since no new functional group was identified. The FTIR spectra also revealed the carbamate formation in DES-CO₂ mixtures. In addition, the densities and viscosities of the synthesized DESs were also measured. The CO₂ initial investigation of reported DESs shows that these can be potential alternative for conventional solvents in CO₂ capture processes.     

Determination of deep eutectic solvents as eco-friendly catalysts for biodiesel esterification from an alcohol-palmitic acid mixture

Deep eutectic solvents (DESs) were prepared by mixing a quaternary salt as a hydrogen bond acceptor with a hydrogen bond donor. In this study, DESs had an excellent effect as a solvent-catalyst for the esterification of palmitic acid and methanol. This method was found to be safe, mild, simple, and eco-friendly. A range of DESs with different mixing ratios were used to optimize the preparation of methyl palmitate. Other factors, such as temperature, time and DESs/methanol ratio, were also examined. The optimal DES was prepared from tetrabutyl ammonium chloride and acetic acid (1 : 2); the methanol and palmitic acid sample to DES ratio was 1 : 0.5 (v/v). The reaction was optimized at a methanol/palmitic acid ratio of 10 : 1 (mol/mol) at 60 °C for 60 min. The yield was 94.3% under the optimized conditions. Therefore, DESs can be developed as a catalyst for the esterification of palmitic acid for obtaining methyl palmitate as biodiesel, and have potential applicability in other biodiesel pretreatments.     

Investigation of CO2 solubility in monoethanolamine hydrochloride based deep eutectic solvents and physical properties measurements

Deep eutectic solvents (DESs) have drawn a growing research interest for applications in a wide range of scientific and industrial arenas. However, a limited effort has been reported in the area of gas separation processes and particularly the carbon dioxide capture. This study introduces a novel set of DESs that were prepared by complexing ethylenediamine (EDA), monoethanolamine (MEA), tetraethylenepentamine (TEPA), triethylenetetramine (TETA) and diethylenetriamine (DETA) as hydrogen bond donors to monoethanolamide hydrochloride (EAHC) salt as a hydrogen bond acceptor. The absorption capacity of CO₂ was evaluated by exploiting a method based on measuring the pressure drop during the absorption process. The solubility of different DESs was studied at a temperature of 313.15 K and initial pressure of 0.8 MPa. The DES systems 1EAHC:9DETA, 1EAHC:9TETA and 1EAHC:9TEPA achieved the highest CO₂ solubility of 0.6611, 0.6572 and 0.7017 mol CO₂·(mole DES)⁻¹ respectively. The results showed that CO₂ solubility in the DESs increased with increasing the molar ratio of hydrogen bond donor. In addition, the CO₂ solubility increased as the number of amine groups in the solvent increases, therefore, increasing the alkyl chain length in the DESs, resulted in increasing the CO₂ solubility. FTIR analysis confirms the DES synthesis since no new functional group was identified. The FTIR spectra also revealed the carbamate formation in DES-CO₂ mixtures. In addition, the densities and viscosities of the synthesized DESs were also measured. The CO₂ initial investigation of reported DESs shows that these can be potential alternative for conventional solvents in CO₂ capture processes.     

苯酚型低共熔溶剂中硫酸钛作为催化剂高效氧化脱硫

低共熔溶剂广泛应用于氧化脱硫过程,开发新型的低共熔溶剂并进一步提升脱硫效果具有重要的意义。 以氯化胆碱为氢键受体,苯酚为氢键供体合成了ChCl/2Ph型低共熔溶剂。通过FT-IR和¹H NMR证实了苯酚和氯化胆碱之间存在氢键作用。以苯酚型低共熔溶剂为萃取剂,双氧水为氧化剂,硫酸钛为催化剂氧化脱除模拟油中的二苯并噻吩。考察了反应温度、V(ChCl/2Ph)/V(Oil)、n(H₂O₂)/n(S)、催化剂用量以及硫化物类型对脱硫率影响。实验表明最佳反应条件如下：模拟油量为5 ml,V(ChCl/2Ph)/V(Oil)=2∶10, n(H₂O₂)/n(S)=6,催化剂用量为0.01 g,反应温度为40℃,反应时间180 min。在此条件下脱硫率可以达到98.2%。求得体系的表观活化能为41.9 kJ/mol。含有催化剂的低共熔溶剂相可以重复使用5次且活性没有明显降低。机理研究表明形成钛的过氧化物和Br?nsted酸性是具有较高脱硫活性的关键。     

新型酚基深共熔溶剂的物性表征及NH3捕集性能研究

NH₃污染问题一直是化工、环保等领域关注的重点问题,对工业尾气中的NH₃进行捕集和回收具有十分重要的意义。以氯化1-乙基-3-甲基咪唑 （［Emim］Cl） 为氢键受体,苯酚、间苯二酚和间苯三酚为氢键供体,构建了一类新型酚基深共熔溶剂。详细测定了酚基深共熔溶剂在不同温度下的密度和黏度,并采用经验方程对密度和黏度数据进行了关联。此外,系统考察了酚基深共熔溶剂对NH₃的吸收-解吸性能和吸收选择性,发现其具有较高的NH₃吸收容量,被吸收的NH₃可在加热和减压的条件下释放出来,经过多次循环NH₃吸收容量基本保持不变。而酚基深共熔溶剂的CO₂吸收容量则较低,因而具有优异的NH₃/CO₂吸收选择性。最后,借助光谱表征和量子化学计算,深入探究了NH₃在酚基深共熔溶剂中吸收的相互作用机制。     

油酚分离过程低共熔溶剂的筛选及萃取性能研究

低温煤焦油中酚类化合物的高效分离在工业上具有重要意义。采用COSMO-RS模型对40种用于间甲酚-异丙苯分离的低共熔溶剂进行筛选,结合σ-profile和σ-potential对筛选得到的低共熔溶剂的高萃取性能进行分析。并采用液液相平衡实验对筛选结果进行验证,优化了萃取工艺条件。结果表明,COSMO-RS模型筛选得到的氯化胆碱(ChCl)∶乙二醇(EG)(1∶2)、ChCl∶丙三醇(Gly)(1∶2)、ChCl∶乳酸(LA)(1∶2)三种低共熔溶剂与间甲酚之间存在较强的氢键相互作用,与异丙苯之间存在排斥作用。液液相平衡实验证实了COSMO-RS筛选结果的可靠性,其中ChCl∶EG(1∶2)具有最高的分配系数和选择性系数,且黏度最低,被选定为最佳的低共熔溶剂。在25℃、ChCl∶EG(1∶2)与模型油质量比为1∶1时,ChCl∶EG(1∶2)对间甲酚萃取率高达98.41%,同时异丙苯夹带量仅为8.41%,并且具有良好的循环使用性能。     

油酚分离过程低共熔溶剂的筛选及萃取性能研究

低温煤焦油中酚类化合物的高效分离在工业上具有重要意义。采用COSMO-RS模型对40种用于间甲酚-异丙苯分离的低共熔溶剂进行筛选,结合σ-profile和σ-potential对筛选得到的低共熔溶剂的高萃取性能进行分析。并采用液液相平衡实验对筛选结果进行验证,优化了萃取工艺条件。结果表明,COSMO-RS模型筛选得到的氯化胆碱(ChCl)∶乙二醇(EG)(1∶2)、ChCl∶丙三醇(Gly)(1∶2)、ChCl∶乳酸(LA)(1∶2)三种低共熔溶剂与间甲酚之间存在较强的氢键相互作用,与异丙苯之间存在排斥作用。液液相平衡实验证实了COSMO-RS筛选结果的可靠性,其中ChCl∶EG(1∶2)具有最高的分配系数和选择性系数,且黏度最低,被选定为最佳的低共熔溶剂。在25℃、ChCl∶EG(1∶2)与模型油质量比为1∶1时,ChCl∶EG(1∶2)对间甲酚萃取率高达98.41%,同时异丙苯夹带量仅为8.41%,并且具有良好的循环使用性能。     

H2S absorption with deep eutectic solvents: Low partial pressure capture and thermodynamic analysis

In the present work, a series of deep eutectic solvents (DESs) based on organic amine as hydrogen bond acceptors (HBAs), and ethylene glycol (EG) as hydrogen bond donor (HBD) were prepared for the H₂S absorption. Thermal decomposition temperature, HBA mass ratios, alkalinity and structure effect on absorption behavior were systematically investigated. The reaction mechanism was demonstrated by FT-IR and ¹H NMR spectroscopy. The reaction equilibrium constants, Henry constant, enthalpy and entropy change were calculated based on the thermodynamic model to reveal the interactions between DESs and H₂S. It was found that H₂S absorption capacities of the most of DESs with HBA/HBD mass ratio of 1:4 was close to 1 mol/mol at 303.15 K and 0.2 bar. The absorption capacity of DESs depends on the alkalinity and structure of HBAs; Additionally, a good linear correlation between the alkalinity of HBA and the absorption equilibrium constant (lnK) of DESs to H₂S was found.