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。     

乙腈+水+离子液体等压汽液平衡测定与计算

采用改进的Ellis平衡蒸馏仪测定了乙腈+水+1-乙基-3-甲基咪唑磷酸二乙酯盐([EMIM][DEP])、乙腈+水+{1-乙基-3-甲基咪唑醋酸盐([EMIM][OAC])+[EMIM][DEP]}常压(101.3 kPa)等压汽液平衡(VLE)数据。实验结果表明,备选离子液体可促进水+乙腈混合物的分离并消除其共沸点。借助NRTL模型成功关联了含离子液体的三元和四元VLE实验数据,获得了乙腈-[EMIM][DEP]、水-[EMIM][DEP]和[EMIM][OAC]-[EMIM][DEP]二元交互作用参数。应用COSMO-SAC预测了实验VLE,结果令人满意。量化计算表明可与水形成强相互作用的离子液体更易促进乙腈与水的分离。     

乙腈+水+离子液体等压汽液平衡测定与计算

采用改进的Ellis平衡蒸馏仪测定了乙腈+水+1-乙基-3-甲基咪唑磷酸二乙酯盐([EMIM][DEP])、乙腈+水+{1-乙基-3-甲基咪唑醋酸盐([EMIM][OAC])+[EMIM][DEP]}常压(101.3 kPa)等压汽液平衡(VLE)数据。实验结果表明，备选离子液体可促进水+乙腈混合物的分离并消除其共沸点。借助NRTL模型成功关联了含离子液体的三元和四元VLE实验数据，获得了乙腈-[EMIM][DEP]、水-[EMIM][DEP]和[EMIM][OAC]-[EMIM][DEP]二元交互作用参数。应用COSMO-SAC预测了实验VLE，结果令人满意。量化计算表明可与水形成强相互作用的离子液体更易促进乙腈与水的分离。     

离子液体中钨酸盐催化氧化模拟汽油脱硫研究

随着燃料油中硫化物含量的标准限值越来越严格,对燃料油中硫化物的脱除工艺技术也提出了更高的要求。合成了十聚钨酸十六烷基三甲基铵[C_(16)H_(33)N(CH_3)_3]_4W_(10)O_(32)和离子液体[Omim]PF_6,分别作为催化剂和萃取剂,构建了[C_(16)H_(33)N(CH_3)_3]_4W_(10)O_(32)/[Omim]PF_6/H_2O_2催化氧化萃取耦合脱硫体系,用于模拟汽油中硫化物二苯并噻吩(DBT)的脱除研究。考察了H_2O_2用量、反应温度、反应时间和催化剂[C_(16)H_(33)N(CH_3)_3]_4W_(10)O_(32)用量对DBT脱除率的影响,结果表明:在H_2O_2与S的摩尔比为4、反应温度50℃、反应时间60 min、催化剂与S的摩尔比为0.02、离子液体与模拟汽油体积比为0.2的条件下,DBT脱除率最高,可达98.6%。     

离子液体基工质对的吸收制冷循环性能实验研究

分别对以离子液体1-乙基-3-甲基咪唑磷酸二乙酯[Emim][DEP]为吸收剂的二元工质对[Emim][DEP]+H₂O和以[Emim][DEP]+LiBr为吸收剂的三元工质对LiBr+[Emim][DEP]+H₂O的吸收制冷循环性能进行了实验研究,用于评价这种新型的工质对的制冷性能。实验结果表明,二元工质对[Emim][DEP]+H₂O具有吸收制冷性能,但与LiBr+H₂O工质对相比,其制冷系数较低。当发生温度为90℃、循环水温度为30℃、蒸发温度在10～15℃时,制冷系数仅为0.16～0.28。主要原因是[Emim][DEP]+H₂O工质对具有较高的黏度和较低的热导率,导致吸收器降膜吸收传热系数较低,吸收器吸收水蒸气的能力不足。为了强化其制冷效果,在[Emim][DEP]+H₂O工质溶液中加入少量LiBr水溶液,构成三元工质对LiBr+[Emim][DEP]+H₂O。实验结果表明,三元工质对LiBr+[Emim][DEP]+H₂O的制冷性能优于二元工质对[Emim[DEP]+H₂O,在上述蒸发温度范围内,制冷系数能够达到0.17～ 0.34,并且制冷温度更低。     

咪唑类[PF_6]^-型离子液体萃取苯胺

研究了以咪唑类[PF6]-型室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐（[Bmim][PF6]）、1-己基-3-甲基咪唑六氟磷酸盐（[Hmim][PF6]）和1-辛基-3-甲基咪唑六氟磷酸盐（[Omim][PF6]）对苯胺水溶液的萃取平衡。实验结果表明：pH值对分配系数的影响很大,在碱性条件下,分配系数较高;萃取过程属于吸热过程;经过四级错流萃取,废水可达到排放标准,萃取相中的苯胺回收率在90%左右,离子液体回收率〉90%,离子液体可以循环利用。     

[bmim][PF6]-DMF-水三元体系的液液相平衡测定

为得到含N,N-二甲基甲酰胺(DMF)废水中萃取回收DMF工艺所需的基础数据,用液液平衡釜常压下测定了1-丁基-3-甲基咪唑六氟磷酸盐([bmim][PF6)离子液体-DMF-H2O三元体系在283.15～323.15 K下的液液分层曲线和液液相平衡数据.在此基础上,考察了三元体系中DMF和[bmim][PF6]离子液体的含量以及温度对[bmim][PF6]的选择性系数的影响.实验结果表明,液液平衡相图中两相区面积随温度升高而减小;相同温度下,[bmim][PF6]的选择性系数随着三元体系中DMF的含量增加而减小,随着离子液体用量增加而增大;溶液组成一定时,[bmim][PF6]的选择性系数随着温度升高而减小;当DMF的含量大于10％时,温度对选择性系数影响不大;283.15 K,三元体系中DMF的质量分数为2.04％时,选择性系数可达33.62,[bmim][PF6]用于萃取分离水中的DMF可行.     

新型磁性离子液体的萃取氧化脱硫研究

通过两步法合成了新型磁性离子液体[C_4DBU]Cl/_2FeCl_3,并利用FT-IR、UV-Vis和VSM对其进行表征。以H_2O_2为氧化剂,考察了离子液体对模拟油中硫化物的萃取氧化脱硫效果。考察了反应温度、反应时间、离子液体质量、氧硫比和硫化物种类对脱硫率的影响。结果表明,在反应温度为60℃、反应时间为100 min、离子液体质量为1.0 g、氧硫比为5时,离子液体对二苯并噻吩的脱除率达98.38%。[C_4DBU]Cl/_2FeCl_3可在外加磁场作用下实现高效回收,且重复使用6次后活性无明显下降。对不同硫化物的脱除效果为DBT4,6-DMDBTBTTH。     

疏水性离子液体萃取芳香化合物及其再生

利用疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐[Bmim][PF6]、1-丁基-3-乙基咪唑六氟磷酸盐[Beim][PF6]、1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐[Bmim][Tf2N]对水溶液中的9种芳香化合物进行萃取,以苯胺为代表对萃取工艺进行了优化,考察了乙醚、正丁醇等低极性溶剂对离子液体的再生情况. 结果表明,在室温下,当相比O/A=0.2、时间为10 min时,[Bmim][PF6]对苯胺的萃取率达87.2%,分配系数为34.1,效果明显高于甲苯、正辛醇等传统有机溶剂. 芳香化合物的分子结构对萃取有较大影响,萃取率及分配系数随溶质疏水性增加而增加. 用乙醚作为反萃剂效果较好,苯胺和离子液体的回收率分别为93.1%和95.2%,溶质及离子液体均能实现资源化回收利用.     

用于芳烃/烷烃体系蒸汽渗透分离的离子液体支撑液膜研究

研究离子液体"填充型"支撑液膜制备规律,以及操作条件对苯/环己烷混合物蒸汽渗透分离过程影响。利用[C4mim][BF4]、[C8mim][BF4]、[C4mim][PF6]、[C6mim][PF6]、[4-Mebupy][BF4]、[3-Mebupy][BF4]离子液体分别制备支撑液膜,用于苯/环己烷混合物蒸汽渗透膜分离过程研究。实验比较了离子液体的种类、操作温度、原料液浓度等因素对苯/环己烷混合体系的蒸汽渗透膜分离性能的影响,其中[3-Mebupy][BF4]制得的支撑液膜对等体积配比的苯和环己烷混合物分离效果最佳,30℃时渗透通量为11.4g?m2?h?1,分离因子可达32.85。通过长时间运行的稳定性实验,证实离子液体支撑液膜的蒸汽渗透过程能够实现苯和环己烷的有效分离,具备良好的稳定性。离子液体"填充型"支撑液膜有望成为降低芳烃/烷烃等有机溶剂体系分离过程能耗的有效途径。     

Imidazolium-based alkylphosphate ionic liquids - A potential solvent for extractive desulfurization of fuel

N-ethyl-imidazolium-based alkylphosphate ionic liquid (IL), viz. N-ethyl-N-methyl-imidazolium dimethylphosphate ([EMIM][DMP]), N-ethyl-N-ethyl-imidazolium diethylphosphate ([EEIM][DEP]) and N-butyl-N-ethyl-imidazolium dibutylphosphate ([BEIM][DBP]) were demonstrated to be effective for the removal of aromatic sulfur compounds (S-compound) 3-methylthiophene (3-MT), benzothiophene (BT) and dibenzothiophene (DBT) from fuel oils in terms of sulfur partition coefficients (K_N) at 298.15 K. It was shown that the extractive ability of the alkylphosphate ILs was dominated by the structure of the cation and followed the order [BEIM][DBP] > [EEIM][DEP] > [EMIM][DMP] for each S-compound studied with their K_N-value being 1.72, 1.61 and 1.17, respectively for DBT. For a specified IL the sulfur selectivity followed the order DBT > BT > 3-MT with their K_N-value being 1.61, 1.39 and 0.78, respectively for [EEIM][DEP]. The alkylphosphate ILs are insoluble in fuel while the fuel solubility in ILs varies from 20.6 mg(fuel)/g(IL) for [EMIM][DMP] to 266.9 mg(fuel)/g(IL) for [BEIM][DBP]. The results suggest that [EEIM][DEP] might be used as a promising solvent for the extractive desulfurization of fuel, considering its higher sulfur extractive ability, lower solubility for fuel and thus negligible influence on the constituent of fuel, and the ease of regeneration for the spent IL via water dilution process.     

表面活性剂与离子液体对β-葡萄糖苷酶的协同影响

为考察表面活性剂和离子液体1-乙基-3-甲基咪唑磷酸二乙酯盐（[EMIM]DEP）对类芽孢杆菌sp. LLZ1 β-葡萄糖苷酶活性的影响,在酶活测定体系中加入一定浓度的表面活性剂和[EMIM]DEP。结果表明：添加5%的[EMIM]DEP使β-葡萄糖苷酶的活性增强了12.00%,进一步添加0.1%鼠李糖脂、Span20、PEG4000和Tween80分别使酶活增强了21.85%、12.07%、8.57%和5.25%,而Triton X-100和SDS分别使酶活降低了4.59%和10.63%。动力学曲线和动力学参数表明随着表面活性剂和5%[EMIM]DEP对β-葡萄糖苷酶活性的增强,米氏常数K_m随之减小。圆二色谱（CD）分析表明分别经0.1%鼠李糖脂、Span20、PEG4000和Tween80处理后,β-葡萄糖苷酶的α-螺旋分别增加1.00%、0.78%、0.72%和0.80%,添加SDS导致α-螺旋减少5.72%。荧光光谱表明同时添加表面活性剂和5%[EMIM]DEP改变了β-葡萄糖苷酶的最大发射波长。差示扫描量热法(DSC)表明0.1%鼠李糖脂和5%[EMIM]DEP提高了β-葡萄糖苷酶的中点温度和平均展开焓。使用0.1%鼠李糖脂协同5%[EMIM]DEP水解纤维二糖,转化率提高了21.93%。     

Experimental Data on Mutual Mass Diffusivities of Binary Mixtures of Ethanol and [EMIM][DEP]

Ionic liquids have been widely discussed for manifold applications in chemical and energy engineering. Reliable molecular transport property data for the heat and mass transfer are indispensable. In this study, the diaphragm‐cell method has been applied to determine the mutual mass diffusivities of binary mixtures of ethanol in the ionic liquid [EMIM][DEP] for various ranges of temperatures and ionic liquid mass fractions. A simple correlation based on the Stokes‐Einstein relation is used to fit the experimental data.     

Measurement of thermal conductivity,viscosity and density of ionic liquid [EMIM][DEP]-based nanofluids☆

This article studied experimentally the effect of multi-wall carbon nanotubes(MWCNTs)on the thermo physical properties of ionic liquid-based nanofluids.The nanofluids were composed of ionic liquid,1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP],or its aqueous solution[EMIM][DEP](1)+ H_2O(2)and MWCNTs without any surfactants.The thermal conductivity,viscosity and density of the nanofluids were measured experimentally.The effects of the mass fraction of MWCNTs,temperature and the mole fraction of water on the thermo physical properties of nanofluids were studied.Results show that the thermal conductivity of nanofluids increases within the range of 1.3%–9.7% compared to their base liquids,and have a well linear dependence on temperature.The viscosity and density of the nanofluids exhibit a remarkable increase compared with those of the base liquids.Finally,the correlation of the effective thermal conductivity and viscosity of the nanofluids was made using the models in the literatures.     

含离子液体溴化1-丙基-3-甲基咪唑的二元和三元体系的蒸气压测定

Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.     

离子液体［Hnhm］H2PO4 催化合成油酸甲酯

合成并表征了离子液体［Hnhm］H₂PO₄ ,同时考察了该离子液体的溶解性及吸水性。以油酸甲酯的合成为探针反应,考察合成的离子液体对反应的催化活性。结果表明,在［Hnhm］H₂PO₄ 加入量为油酸质量的8%、n(甲醇)∶n(油酸)=3.5∶l、反应温度90 ℃和反应时间9 h条件下,油酸酯化率达63%以上,且［Hnhm］H₂PO₄离子液体与原料及产物的分离容易实现。     

Determination of Vapor Pressures for Binary and Ternary Mixtures Containing Ionic Liquid 1-propyl-3-methylimidazolium Bromide

Vapor pressure values of binary systems water + ethanol, water + ionic liquid 1-propyl-3-methylimidazolium bromide ([PMIM][Br]), ethanol + [PMIM][Br] and ternary system water + ethanol + [PMIM][Br] at different temperatures were measured by using a modified boiling point method in various concentrations of (16.66%, 33.7%), (17.4%, 33.9%) and (16.5%, 32%) mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation (AAD) was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.     

Molecular dynamics simulation of supercritical CO2 microemulsion with ionic liquid domains: Structures and properties

Supercritical carbon dioxide microemulsions are great medium to combine two immiscible substances through forming nanoscale polar cores in nonpolar continuous phase with the help of proper surfactants. The properties of microemulsions could be significantly affected by their constituents and structures. In this work, molecular dynamics simulation was implemented to study supercritical carbon dioxide microemulsions containing ionic liquid[bmim] [PF₆] and water by adding surfactant Ls-36. Results showed that the above components could form spherical aggregates in CO₂ bulk phase with[bmim] [PF₆] and some water as the inner core, surfactant headgroups and water as the intermediate shell, and surfactant tails as the outer shell. The microstructure information about the outer shell was further investigated by defining an angle between the surfactant tail and the normal direction of the aggregate outer surface, which ranged from 78° to 125°. The influence of the ionic liquid content on the size and structure of microemulsions was explored and the best molar ratio between the ionic liquid and surfactant was around 1.25 for getting maximum water solubility.