离子液体催化苯与长链烯烃烷基化的连续反应性能

在强制混合-反应-分离-循环实验装置上考察了酸性氯铝酸盐室温离子液体[BMIM][AlCl4]催化苯与长链烯烃烷基化反应的连续操作、沿反应管侧线分布式连续进料和工业烯烃原料进料的连续反应性能。实验结果表明,即使在相对苛刻的反应条件下,纯烯烃原料1-十二烯单程转化率也能在反应器内达到100.0%,2-苯基异构体选择性高于37.7%。虽然侧线连续进料的位置不同,但在反应器出口前1-十二烯可完全转化。精制过的工业烯烃原料可以满足连续烷基化反应的要求。     

离子液体催化氯乙酸甲酯合成氯乙酸-2-庚酯的研究

探索了离子液体催化氯乙酸甲酯和2-庚醇的酯交换反应,制备了1-甲基-3-（丙基-3-磺酸基）咪唑对甲苯磺酸盐[MIM-PS][PTSA]、1-甲基-3-（丙基-3-磺酸基）咪唑硫酸氢盐[MIM-PS][HSO₄]、1-丁基-3-甲基咪唑硫酸氢盐[BMIM]HSO₄、N-甲基咪唑磷酸盐[HMIM]H₂PO₄四种离子液体催化剂并用于酯交换反应,通过考察产品氯乙酸-2-庚酯收率,筛选出最佳催化剂[MIM-PS][PTSA]。并用[MIM-PS][PTSA]考察了反应温度、反应时间、催化剂添加量、催化剂循环使用对合成产品收率的影响。结果表明：将氯乙酸甲酯和2-庚醇在100 ℃下,添加5% [MIM-PS][PTSA]催化剂,反应6 h,合成氯乙酸-2-庚酯,收率可达76.3%,离子液体重复使用3次,氯乙酸-2-庚酯收率仍大于初次收率的95%。本实验用离子液体做溶剂或催化剂,反应条件稳定,可循环利用、对环境友好,且产品收率高,为工艺放大提供实验条件参考。     

用差示扫描量热法研究环氧树脂-咪唑改性双氰胺离子液体体系

用差示扫描量热法对双酚A型环氧树脂(Epikote 828E)/咪唑改性双氰胺离子液体([BMIM][DCA])体系的交联反应进行了研究,研究了交联剂[BMIM][DCA]用量对Epikote828E交联度的影响,并利用Kissinger,Ozawa和Crane动力学方程计算体系的交联反应动力学参数。结果说明相对于双氰胺,[BMIM][DCA]具有更高的反应活性。反应的起始温度(T_i)、峰顶温度(T_p)和峰终温度(T_f)分别在373、425和453K左右,反应的表观活化能(E_k、E_o)和指前因子分别为64.3、67.9kJ/mol和3.17×10~4 s~(-1)。交联反应是一级反应。上述参数可以为Epikote 828E-[BMIM][DCA]体系的固化、性能和应用提供理论依据,也可为其他离子液体作为环氧固化剂研究的参考。     

离子液体催化苯与1-十二烯烷基化的循环反应-分离实验装置

针对酸性氯铝酸盐室温离子液体［BMIM］［AlCl₄］催化苯与1-十二烯烷基化合成十二烷基苯（LAB）反应体系双液相、反应速率高和催化剂对湿气敏感的特点,建立了一套既可间歇操作也可连续操作的强制混合-反应-分离-再循环实验装置.循环物料和离子液体的混合与烷基化反应在一台静态混合反应器中进行,反应后料液和离子液体在一台液-液沉降器中进行分离.运行结果表明,在一定的物料循环和离子液体注入流量范围内,可以实现离子液体催化剂和反应料液的高效、快速混合与分离,催化剂被有效地保留在反应系统内并实现了它的再循环.     

离子液体用于四氢呋喃-乙醇-水三元共沸物系分离的研究

以离子液体1-丁基-3-甲基咪唑二氰胺（[BMIM] [DCA]）为萃取剂,采用流程模拟和机理分析两种方法,对离子液体用于四氢呋喃（THF）-乙醇-水三元共沸物的分离进行了研究。通过COSMO-RS理论,以选择性为性能指标筛选出合适的离子液体[BMIM][DCA],并且以[BMIM][DCA]为萃取剂,在适合的操作条件下建立了萃取精馏过程,模拟结果表明THF、乙醇和水的质量分数都接近1。通过对[BMIM][DCA]和三种溶质的σ-谱图分析,发现[BMIM][DCA]可分别与三种溶质形成更强的氢键,从而打破三种溶质间的固有氢键,进而消除它们的共沸现象。     

[BMIM]HSO4/Al2O3催化剂的制备及其在甘油脱水反应中的应用

采用两步法合成离子液体[BMIM]HSO4,并采用浸渍法制备了[BMIM]HSO4/Al2O3固载型离子液体催化剂,用TG-DTG、BET、SEM等方法对催化剂进行表征。在常压连续流动的固定床反应器中,考察甘油制备丙烯醛的工艺条件,重点考察了反应温度、离子液体的负载量、体积空速对反应的影响及催化剂的稳定性。结果表明,较优条件为：当催化剂为[BMIM]HSO4/Al2O3,负载量为40%、反应温度为300℃、体积空速为6 h-1时,丙烯醛的选择性可达90.22%,甘油的转化率为100%,且催化剂在使用100 h后仍保持75%的收率。     

硫酸/离子液体催化合成三聚甲醛的实验与分子模拟研究

以3种烷基咪唑类酸性离子液体与硫酸组成的复合催化剂取代纯硫酸作为三聚甲醛合成的催化剂。结果表明,在相同反应条件下,硫酸/1-乙基-3-甲基咪唑硫酸氢盐([EMIM][HSO₄])作为催化剂时,产物三聚甲醛的平衡浓度可以提高17%。分子动力学模拟研究表明,[EMIM][HSO₄]可以改变反应体系粒子间微观结构。加入[EMIM][HSO₄]后,会改变体系的扩散行为,减弱水合氢离子与硫酸氢根离子之间的相互作用,增大硫酸氢根离子与水分子之间的相互作用。从理论上解释了硫酸/[EMIM][HSO₄]改善三聚甲醛合成反应的原因。     

离子液体用于燃油萃取脱硫的选择与过程优化

针对基于COSMO-SAC模型分子设计方法的准确性问题,采用离子液体脱硫机理分析和实验的方法对其进行了验证,即对[HMIM][BF_4]、[HMIM][PF_6]、[BMIM][BF_4]、[BMIM][PF_6]、[EMIM][BF_4]、[EMIM][PF_6]6种离子液体作萃取剂时的脱硫效果进行了脱硫机理的分析和实验的验证,得到的脱硫性能排序与离子液体分子设计结果基本一致,且均认为[HMIM][PF_6]脱硫率较高。以[HMIM][PF_6]为萃取剂,通过液相色谱法测定萃取后的液相组成,考察萃取时间、萃取温度、剂油比3个因素对脱硫率、分配系数和选择性系数的影响。通过正交实验设计确定了萃取时间40 min、萃取温度20℃、剂油比2:1为较优操作条件,单次脱硫率为72.74%,四级萃取可将模型油的含硫量由1200μg·g~(-1)降至6.98μg·g~(-1),符合国Ⅴ标准。     

1，3-二烷基咪唑类离子液体的合成研究

通过N-烷基化反应制备了中间产物氯化-1-丁基-3-甲基咪唑[BMIM]Cl离子液体,得到较佳的制备条件。引入微波辅助改进了[BMIM]Cl合成方法。同时在超声波辅助下,通过离子交换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以及憎水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF6。结果发现,微波辅助和超声波辅助可以加速反应速度。产物结构用IR和1H NMR进行表征。     

离子液体和有机溶剂中薄荷醇催化选择性酯化

研究了离子液体和有机溶剂中(dl)-薄荷醇立体选择性酯化反应。结果表明,在疏水性离子液体[BMIM][PF6]和正己烷介质中的薄荷醇酯化率较高。通过对反应温度、孵育时间和回收次数等影响因素的测定,发现离子液体[BMIM][PF6]作为酶催化反应介质具有比正己烷更大的优势。尤其是酯酶在离子液体中孵育60 d后表现出的活性增大为原来的2.5倍,而正己烷中的酶活性则在两天内变为原来的60%。此外,离子液体在回收利用中表现的优势更说明它作为绿色溶剂替代传统有机溶剂的巨大潜力。     

Recycling and Activity Recovery of Chloroaluminate Ionic Liquid as Catalyst for Alkylation of Benzene with 1-Dodecene

Performances of 1-butyl-3-methylimidazolium aluminium chloride ([BMIM]Cl-AlCl3) ionic liquid as catalyst for the alkylation of benzene with long chain olefins were investigated in a continuous operation mode. A small pilot plant with continuous mixing-reacting-separating-recycling functions, equipped with a static mixer reactor, a tube packed with metal Al thread and a combined liquid-liquid settling phase separator, was introduced as an alternative. The results showed that the continuous fast mixing and separation of ionic liquid catalyst from reactant mixture could be synchronously accomplished within a wider flow rate ratio range of the recycling reaction mixture to the ionic liquid catalyst. The recycling of chloroaluminate ionic liquid was realized. ICP-AES detection results of Al content in the reactants proves that in-situ Al compensation to the reaction system may be an important choice to prolong the stable running time of moisture-sensitive ionic liquid [BMIM]Cl-AlCl3 when feedstock inevitably contains trace water. It suggests that the activity of chloroaluminate ionic liquid is recovered under the in-situ Al compensation operation.     

[Bmim]Cl-xAlCl_3催化合成十二烷基苯

采用AlCl3和[Bmim]Cl不同摩尔比的[Bmim]C1-xA1C13离子液体为催化剂,研究了不同条件下1-十二烯与苯的烷基化反应。实验结果表明,以A1Cl3和[Bmim]Cl的摩尔比为2.0([Bmim]Cl-2A1C13)的离子液体为催化剂,在反应温度25℃、反应时间30 min,苯、烯及离子液体的摩尔比为5︰1︰0.03的条件下,正十二烯的转化率可达98.32%,2-LAB的选择性可达36.76%。离子液体和产物可形成易于分离的双液相,简化了催化剂与产物的分离操作。     

Preparation of well-defined dendrimer encapsulated ruthenium nanoparticles and their application as catalyst and enhancement of activity when utilised as SCILL catalysts in the hydrogenation of citral

Silica supported dendrimer encapsulated ruthenium nanoparticles were prepared and evaluated as catalysts in the hydrogenation of citral. The dendrimer encapsulated nanoparticles were prepared using the generation 4 (G4), generation 5 (G5) and generation 6 (G6) hydroxyl-terminated poly(amidoamine) (PAMAM-OH) dendrimers as templating agents with different Ru metal:dendrimer ratios. The effects of ionic liquids as catalyst coatings on the catalytic activity were investigated for the ionic liquids [BMIM][NTf₂], [OMIM][NTf₂], [BMIM][BF₄], [BMIM][PF₆], [EMIM][OcS] and [EMIM][EtS]. An enhancement in catalytic activity was observed when utilising [BMIM][NTf₂] as an ionic liquid coating with selectivity towards citronellal.     

Simple, efficient and recyclable palladium catalytic system for Heck reaction in functionalized ionic liquid network

In functionalized ionic liquid network of [BMIM][TPPMS] and [BMIM][OAc], PdCl₂(CH₃CN)₂ efficiently catalyzed the Heck reaction of bromobenzene to ethyl cinnamate with yield of 60% and without the activity loss even after 11 recycling uses. The beneficial influences of this ionic liquid network on activity and stability were explained in terms of synergic ligand effects of [BMIM][TPPMS] and [BMIM][OAc], no accumulation of sodium or ammonium bromides by using [BMIM][OAc] as base, and the positive effect of [BMIM]Br by avoiding the formation of palladium black. The generality of this ionic liquid system to the different substrates also gave the pleasing results.     

甲醇-乙酸甲酯-1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐的等压汽液平衡

测定了101.3 kPa下甲醇-乙酸甲酯-1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐（[BMIM］［Tf2N］）体系的汽液平衡,并用NRTL方程对测得的汽液平衡数据进行了回归,得到方程的二元参数。实验表明［BMIM］［Tf₂N］能够显著提高甲醇对乙酸甲酯的相对挥发度,并且随着［BMIM］［Tf₂N］含量的增加,甲醇对乙酸甲酯的相对挥发度增大。将萃取剂［BMIM］［Tf₂N］与1-辛基-3-甲基咪唑六氟磷酸盐（［OMIM］［PF₆］）进行了对比,结果表明对于甲醇-乙酸甲酯体系,［BMIM］［Tf₂N］具有更高的分离效率。     

离子液体催化丁醇与盐酸反应制备丁基氯

The catalytic performance of some quaternary ammonium salts for the liquid phase reaction of butanol and hydrochloric acid at different conditions was studied experimentally and compared with the traditional catalyst （ZnCl2）. The organic ammonium catalysts investigated include ionic liquids N-butyl-N-methyl imidazolium fluoborate （[BMIM][BF4]） and N-butyl-N-methylimidazolium chloride （[BMIM]Cl） as well as hydrochloric salts of N-methylimidazol （[HMIM]Cl）, pyridine （[HPy]Cl） and triethylamine （[HEt3N]Cl）. It is shown that the intrinsic catalytic performance of all organic ammonium salts except [HEt3N]Cl is slightly superior to ZnCl2, while the selectivity of butyl chloride is nearly at the same level around 96%. The conversion of butanol increases slightly with temperature and the catalyst amount added while the variation of selectivity is not obvious. Based on the recycle experiments, the ionic liquids as catalyst for the reaction of butanol and hydrochloric acid can be used more than 5 times, which suggests great potential of using ionic liquids as novel catalyst for such reactions.     

Desulfurization of Diesel Fuel by Extraction with Lewis-Acidic Ionic Liquid

Abstract

Ionic liquids were found to be highly selective for the extractive removal of aromatic sulfur compounds from fuels at room temperature. The efficiency of ionic liquids for the removal of aromatic sulfur compounds is dependent on the properties and structure of the ionic liquids. In this work, the Lewis-acidic ionic liquid 1-butyl-3-methylimidazolium tetrahalogenoferrate(III) ([BMIM] [FeCl₄]) was synthesized and demonstrated to be more effective for the removal of aromatic sulfur compounds from diesel over ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF₄]) because of its Lewis-acidic property. The ionic liquids favorably extracted organic compounds with a higher density of aromatic π-electrons. [BMIM][FeCl₄] ionic liquid can be regenerated through reextraction by hexane, and could be used in multiple steps for the removal of sulfur compounds from diesel.     

Brønsted acidic ionic liquids as novel catalysts for Prins reaction

Prins reaction, used to prepare dioxanes, has been limited by complex catalyst separation and reusability. In this article, six water-stable Brønsted acidic task-specific ionic liquids ([HMIM]BF₄,[(CH₂)₄SO₃HMIM][HSO₄], [(Ac)₂BIM]Br, [NMP][HSO₄], [BMIM][HSO₄] and [BMIM][H₂PO₄] were synthesized and used as environmentally benign catalysts for Prins reaction under mild reaction conditions for the first time. The process is highly effective and environmentally benign. Furthermore, [BMIM][HSO₄] was conveniently separated with the products and easily recycled to catalyze Prins reaction again with excellent yields.