离子液体1-己基-4-甲基吡啶四氟硼酸盐与烃类的相互作用规律

为研究离子液体1-己基-4-甲基吡啶四氟硼酸盐([C6MPy][BF4])与烃类之间的相互作用规律,考察了[C6MPy][BF4]对不同结构C10烃类的溶解能力,讨论了该离子液体对不同C10芳烃的选择性;并用Gaussian软件和密度泛函理论计算了[C6MPy][BF4]与不同芳烃混合后的优化构象和离子对作用能,探讨了...     

新型马尿酸盐类离子液体的腐蚀性与摩擦学性能

设计开发了3种马尿酸盐类离子液体：1-丁基-3-甲基咪唑马尿酸盐离子液体[BMIM][Hip]、胆碱马尿酸盐离子液体[CHO][Hip]和三丁基十四烷基鏻马尿酸盐离子液体[P₄₄₄₁₄][Hip],通过电化学和摩擦学方法分别考察了这3种离子液体对低碳钢的腐蚀性,及其作为润滑剂对钢/钢摩擦副的摩擦学性能,并与传统1-丁基-3-甲基咪唑四氟硼酸盐离子液体([BMIM][BF₄])进行比较。结果表明：传统离子液体[BMIM][BF₄]对低碳钢的腐蚀性较强;合成的3种离子液体对低碳钢的腐蚀性均非常弱,其中[CHO][Hip]对低碳钢的腐蚀性最弱;此外,合成的3种离子液体在钢/钢摩擦副上均表现出优异的摩擦学性能,使用[BMIM][Hip],[CHO][Hip],[P₄₄₄₁₄][Hip]润滑时摩擦副的磨损量分别为使用[BMIM][BF₄]润滑时磨损量的9.3%,5.3%,18.1%。     

1-丁基-3-甲基咪唑六氟磷酸盐中PCl5催化的两相贝克曼重排反应

在1-丁基-3-甲基咪唑六氟磷酸盐([bmim][PF6])离子液体与甲苯组成的两相体系中，以PCI5为催化剂，实现了由环已酮肟制备已内酰胺的高效、高选择性液相贝克曼重排反应。该两相体系有利于实现反应控制和体系取热。分别考察了环已酮肟用量、PCI5用量、离子液体体积、反应温度和反应时间对环已酮肟转化率、已内酰胺选择性和PCIs的催化转化数的影响。优化的重排反应条件是：2．0mL[bmim][PF6]／5．00mL甲苯，0．405 g PCI5，10．0mmol环已酮肟，80℃，反应时间10～30mim。在此条件下，环已酮肟转化率达99．72％，己内酰胺选择性达98．90％，PCI5的催化转化数达5．14。99．5％以上的已内酰胺在离子液体相。     

[CnMIM]BF4型离子液体水洗反萃取回收方法的研究

用蒸馏水作反萃取剂,对脱硫试验后的离子液体进行再生,考察了蒸馏水用量、水洗时间和萃取温度等条件对再生后离子液体脱硫效果的影响,并对烷基咪唑四氟硼酸盐类离子液体[C5MIM]BF4,[C7MIM]BF4,[C8MIM]BF4,[C10MIM]BF4进行了多次重复再生试验。结果表明,最佳再生条件为：V(H2O):V([CnMIM]BF4)=1︰2,在室温下萃取5 min,分离出水相后进一步对离子液体进行真空干燥除水。除[C5MIM]BF4对水具有一定的溶解性外,[C7MIM]BF4,[C8MIM]BF4,[C10MIM]BF4几乎不溶于水,再生15次后脱硫效果仍然良好,汽油脱硫率分别达到64.09 %,72.41 %,75.80 %。     

[bmim]OH和[A336][FeCl_4]混合离子液体氧化吸收硫化氢

为了降低非水相催化氧化硫化氢体系的运行成本,将碱性的氢氧化1-丁基-3-甲基咪唑([bmim]OH)离子液体与价格较低的酸性三辛基甲基铵四氯铁酸盐([A336][FeCl_4])离子液体分别按照0.2∶1、0.5∶1、0.8∶1、1∶1和2∶1的比例混合,用所得到的混合离子液体进行硫化氢氧化吸收实验,系统研究了混合离子液体的水溶性、密度、红外光谱、黏度和酸性强度等性能,并对其硫容和反应产物进行了分析。研究结果表明:(1)[A336]FeCl_4季铵盐离子液体的酸性强度和价格均低于[bmim]Fe Cl4离子液体,可以降低离子液体非水相催化氧化硫化氢体系的成本;(2)混合离子液体不仅同时具有[bmim]OH和[A336][FeCl_4]的骨架结构,且其p H值、黏度和硫容均随[bmim]OH量的增加而增加;(3)混合离子液体明显弱于[A336][FeCl_4]离子液体的酸性强度,有利于硫化氢的吸收,其黏度随温度上升而剧烈下降的性质有利于中、高温脱硫。结论认为,当[bmim]OH/[A336][FeCl_4]的物质的量之比在0.5∶1~1∶1时,可以构建成本较低、酸性适中、黏度较低、硫容较高的中、高温脱硫体系。     

1-丁基-3-甲基咪唑六氟磷酸盐萃取香豆素

实验采用疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([C_4mim][PF_6])代替挥发性有机溶剂,由水相中萃取香豆素。采用紫外分光光度法测定了香豆素质量浓度,考察了温度、pH值、相比、香豆素质量浓度、萃取时间等因素对萃取效果的影响。结果表明,在10～50℃和pH=1～11条件下,温度和pH值对萃取效果几乎无影响;当萃取时间为10 min、V(香豆素水溶液):V([C_4mim][PF_6])=3:1、香豆素质量浓度为1.0g/L时,萃取效果最好;在该条件下,以100mL[C_4mim][PF_6]为萃取剂,平均萃取率达94.55%。离子液体中的香豆素用3倍体积量的NaOH水溶液反萃取3次,可将香豆素完全转移到水相;离子液体相用蒸馏水洗至中性,80℃减压干燥5 h后可重新使用。     

离子液体中季铵型六聚钨酸盐相转移催化氧化脱硫性能

制备了亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)和4种季铵型六聚钨酸盐催化剂,通过FTIR,UV-Vis,TG等方法对它们的结构进行了表征;考察了以H2O2为氧化剂,季铵型六聚钨酸盐催化剂在离子液体[Bmim]BF4中相转移催化氧化模拟油中二苯并噻吩(DBT)的活性。实验结果表明,随H2O2和催化剂用量的增加、反应温度的升高和反应时间的延长,DBT脱除率单调增加;适宜的反应条件为:以季铵型六聚钨酸盐[C18H37(CH3)3N]2W6O19为催化剂,模拟油用量5mL、离子液体[Bmim]BF4用量1 mL、反应温度50℃、反应时间3.0 h、n(催化剂)∶n(DBT)=1∶10、n(H2O2)∶n(DBT)=4;在此条件下,该脱硫体系的DBT脱除率可达99.6%,其脱硫效果好于仅用离子液体萃取脱硫和无离子液体的催化氧化脱硫体系的脱硫效果。     

1-乙酸乙酯基-3-甲基咪唑四氟硼酸盐离子液体用作润滑剂的探讨

合成了含羧酸酯基官能团的功能化离子液体--1-乙酸乙酯基-3-甲基咪唑四氟硼酸盐([EAMIM]BF4),考察了其物化性质、高低温下的摩擦学性能以及对传统润滑油添加剂的相溶性和感受性,并选择含有相同烷基的1-丁基-3-甲基咪唑四氟硼酸盐传统离子液体([BMIM]BF4)作为对比。结果表明：两种离子液体具有较好的低温流动性、低的蒸发损失和高的热稳定性;能溶解部分具有强极性和杂环化合物的传统润滑油添加剂,但不能溶解大多数常用的油溶性添加剂,[EAMIM]BF4对添加剂的溶解性比[BMIM]BF4弱;在室温及高温条件下,[EAMIM]BF4由于粘度较大减摩性稍差,但抗磨性比[BMIM]BF4强;极压抗磨剂亚磷酸二正丁酯能提高[BMIM]BF4的抗磨作用,但与[EAMIM]BF4呈现出对抗效应,导致其润滑性能降低。     

VGO分子在FAU分子筛中的扩散研究

应用分子模拟技术计算了VGO模型化合物中刚性基团的尺寸和VGO分子尺寸,利用分子动力学模拟在800K催化裂化反应温度下VGO分子在FAU型分子筛内的扩散过程,并通过计算扩散穿透距离,研究不同类型VGO分子在FAU型分子筛内扩散能力的差异。结果表明:分子中刚性基团的尺寸和VGO分子碳链长度是影响VGO分子在FAU型分子筛内扩散能力的主要因素;直链烷烃的链长增加,烃分子在扩散时易发生卷曲,扩散能力降低;环烷烃、芳烃环数的增加或分子中含有支链会增加烃分子刚性基团的尺寸,进而降低烃分子的扩散能力;烃分子与多环芳烃混合进行扩散,难扩散的多环芳烃占据分子筛孔道,堵塞孔道而降低易扩散烃分子的扩散能力。     

离子液体中水溶性铑膦配合物催化高碳烯烃氢甲酰化反应

研究了若干水溶性铑膦配合物在离子液体中的高碳烯烃氢甲酰化反应性能.在[BMI]BF4-有机两相体系中,水溶性TPPTS-铑配合物表现出高于其在水-有机两相中的1-己烯氢甲酰化反应活性;而对于具有表面活性功能两亲性膦配体与铑形成的配合物,则表现出低于其在水-有机两相体系中的催化活性.另一方面,在[BMI]BF4-有机两相体系中,无论水溶性还是两亲性配体与铑形成的配合物,均表现出较好的催化活性和产物选择性稳定性;实验结果揭示,离子液体[BMI]BF4不仅具有较弱的表面活性功能,而且可作为"固载"水溶性膦-铑配合物的有效新介质.     

A New Approach to Dearomatization of Gasoline by Ionic Liquid and Liquid–Liquid Extraction

Abstract

The objective of this article was the development of a separation technology for the selective recovery of the aromatic compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX) from gasoline by extraction. A liquid–liquid extraction method using ionic liquid (IL) was optimized simultaneously for some aromatic hydrocarbons in gasoline. 1-Butyl-3-methyl imidazolium tetrachloroaluminate ionic liquid or [BMIM][AlCl₄] was used to extract aromatic compounds from gasoline. [BMIM][AlCl₄] was found to be effective for the selective removal of aromatic hydrocarbons from gasoline. The dearomatization experiments were carried out with a 1:1 volume ratio of ionic liquid to gasoline for 60 min at 50°C. The aromatic hydrocarbons removal selectivity followed the order benzene > toluene > xylene > ethylbenzene.     

Effect of the Structure of Cations and Anions of Ionic Liquids on Separation of Aromatics from Hydrocarbon Mixtures

1. Introduction Benzene is a key chemical in the chemical industry, used as the raw material for producing polymer precursors, solvents, dyes, drugs, herbicides, and so on. The world production of benzene is more than 2.0×107 tons/year (Vervalin, 1991; Weissermel and Arpe, 1993; Villaluenga and Tabe-Mohammadi, 2000). Before World War II, benzene was mainly produced from coal, but nowadays more than 90% is obtained from petroleum, mainly from catalytic reformates and FCC gasoline, and by …     

糠醛与芳烃分子间作用力的本质研究

采用分子动力学和量子力学相结合的方法,对糠醛精制润滑油基础油工艺中糠醛与不同环数芳香烃的相互作用进行了计算.结果表明:糠醛与芳香烃的相互作用能和静电作用能均随着芳环数目的增多而增大,这是由于多环芳烃的离域π电子更容易受到外部电场的诱导,从而产生诱导偶极矩;糠醛分子在与芳烃形成二聚体时,单体分子间有电子转移现象;溶剂分子...     

减压渣油胶体稳定性的分子模拟研究

分子结构特性决定分子间相互作用,进而决定其溶解性能。通过分子模拟研究减压渣油不同结构分子的分子间相互作用、互溶性及由此导致的渣油胶体稳定性。研究表明,芳环数目越多、烷基侧链越短的分子结构内聚能密度越大,溶解度参数越大。在渣油体系中,沥青质、重胶质分子聚集形成胶核,饱和烃、芳香烃、轻胶质分子形成连续相。胶质分子结构影响其胶溶性能,侧链长度适中的胶质分子,其与沥青质、芳香分互溶性好,胶溶性能优异;沥青质的聚集程度随胶质分子含量的增加而降低。芳香分、胶质分子的协同作用使沥青质、饱和烃分子稳定存在于同一体系中,因此渣油胶体稳定性取决于不同分子结构的连续性和配伍性。     

Desulfurization From Model of Gasoline by Extraction With Synthesized [BF4]−- and [PF6]−-based Ionic Liquids

Abstract

The authors report that 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF₄], and 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF₆], ionic liquids were synthesized and tested for their capability to desulfurization from model of gasoline. The results show that the aromatic sulfur compounds with higher π-electron density were favorably adsorbed. The results also show that [BF₄]^?-based ionic liquid displays higher extraction efficiencies than [PF₆]^?-based ionic liquid. Thus, it was shown that the extractive ability of the imidazolium ionic liquids was dominated by the structure of cation and anion. It is also found that the sizes of ionic liquids are important factors affecting the absorption capacity for aromatic sulfur compounds.     

Removal of basic nitrogen compounds from fuel oil with [C4mim]Br/ZnCl2 ionic liquid

Metal-based ionic liquid [C₄mim]Br/ZnCl₂ was synthesized, and its structure was characterized using FTIR spectroscopy and a mass spectrometer. The denitrogenation performance of the ionic liquid was investigated using coker diesel oil as feedstock. Experiment results showed that [C₄mim]Br/ZnCl₂ presented a good denitrogenation performance, obtaining about 94.95% basic N-removal efficiency under the condition with a temperature of 50°C, 1:1 (w/w) IL:oil, extraction time of 30 min. In addition, the basic N-removal efficiency can still reach above 50% at 1:7 IL/oil (w/w) during four recycles of the ionic liquid.     

[C4mim]HSO4离子液体脱除页岩油柴油馏分中氮化物的研究

合成了1-丁基-3-甲基咪唑硫酸氢盐离子液体,并以氮含量高的抚顺页岩油柴油为原料考察其脱氮性能。分别研究了温度、油/IL质量比、水/IL、反应时间、沉降时间等因素对总氮和碱性氮脱除效率的影响。试验结果表明：该离子液体具有较好的脱氮性能,在抽提温度30℃、油剂质量比7:1、水剂质量比2:1、抽提时间20min、沉降时间2h的条件下,碱氮和总氮脱除率分别为90%、71%,且离子液体回用5次,其碱氮脱除率仍可达到74%。     

Fluid phase equilibrium prediction of acid gas solubility in imidazolium-based ionic liquids with the Peng-Robinson and the PC-SAFT models

In this research, the solubility of two single gases, hydrogen sulfide and carbon dioxide, in the sixteen ionic liquids ([emim][eFAP], [emim][EtSO₄], [emim][OTf], [emim][Tf₂N], [bmim][BF₄], [bmim][OTf], [bmim][PF₆], [bmim][Tf₂N], [hmim][PF₆], [hmim][Tf₂N], [omim][PF₆], [omim][Tf₂N], [HOemim][BF₄], [HOemim][OTf], [HOemim][PF₆] and [HOemim][Tf₂N]) are modeled using the Peng-Robinson and the PC-SAFT equations of state. For the ionic liquids, the pure component parameters of the PC-SAFT EoS have been obtained by the predictions of the model to both of experimental H₂S and CO₂ solubility data in ionic liquids as well as experimental liquid density data. Also, the critical properties and acentric factor of the ionic liquids were estimated using the modified Lydersen-Joback-Reid method. In the next step, the temperature-independent interaction parameters between the ionic liquids and the gases for both equations of state were calculated by fitting to the experimental VLE data and the obtained results were analyzed. In most of the studied binary systems, the percent average absolute deviation was lower than 10% that shows good agreement between the experimental and predicted values.