Measurement and Prediction of Vapor Pressure for H2O+CH3OH/C2H5OH+[BMIM][DBP] Ternary Working Fluids

The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1)+[BMIM][DBP](2) were measured...     

单乙醇胺和二乙醇胺甲酸盐离子液体对水、甲醇和乙醇挥发度的影响(英文)

Vapor pressures were measured for six binary systems containing water, ethanol, or methanol with one of the two ionic liquids （ILs） at different component concentrations and temperatures using a quasi-static ebulliometer, with the ILs mono-ethanolammonium formate （[HMEA][HCOO]） and di-ethanolammonium formate （[HDEA][HCOO]）. The vapor pressures of the IL-containing binary systems are well correlated using the NRTL model with an overall average absolute relative deviation （AARD） of 0.0062. The effect of ILs on the vapor pressure depression of sol-vents at 0.050 mole fraction of IL is that [HDEA][HCOO]〉[HMEA][HCOO], and the vapor pressure lowering de-gree follows the order of water〉methanol〉ethanol. Further, the activity coefficients of three solvents （viz. water, ethanol, and methanol） for the binary systems{solvent （1）＋IL （2）}predicted based on the fitted NRTL parameters at T=333.15 K indicate that the two ILs generate a negative deviation from Raoult’s law for water and methanol and a positive deviation for ethanol to a varying degree, change the relative volatility of a solvent. [HMEA][HCOO] may be a promising entrainer to efficiently separate ethanol aqueous solutions by special rectification.     

乙腈+[C4mim][Cl]、乙腈+[C4mim][BF4]、乙腈+[C6mim][Cl]的气液平衡测定与关联（英文）

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ([C6mim][Cl]) at temperatures of 313 to 353 K by a quasi-static method. The experimental data for the binary sys-tems were correlated by the non-random two liquid (NRTL) equation with an average absolute relative deviation (AARD) of within 1.84%. The results indicate that the three ionic liquids (ILs) can result in a negative deviation from the Raoult's law for the binary solutions containing acetonitrile, and the affinity between ILs and acetonitrile mole-cules fol ows the order [C4mim][BF4]+acetonitrile N [C4mim][Cl]+acetonitrile N [C6mim][Cl]+acetonitrile.     

1,3-二甲基咪唑四氟硼酸盐的合成及其水溶液的蒸气压测定

In absorption cycles,ionic liquid(IL)1,3-dimethylimidazolium tetrafluoroborate([Dmim]BF4)may be a promising absorbent of working pair using water as refrigerant.The vapor pressures of[Dmim]BF4 aqueous solution were measured with the boiling-point method in the temperature range from 312.25 to 403.60 K and in the mass concentration range of 65%to 90%of[Dmim]BF4.The experimental data were correlated with an Antoine-type equation and the Non-Random Two-Liquid(NRTL)model,and the average absolute deviations between the experimental and calculated values were 1.06%and 1.15%,respectively.For the[Dmim]BF4 aqueous solution,the experimental vapor pressures show negative deviations from the calculated data with Raoult’s law.For higher mass concentration of the IL,the deviation is more negative.In addition,the vapor pressures,the hydrophilicity and the solubility of[Dmim]BF4 aqueous solutions were compared with those of[Dmim]Cl aqueous solutions and [Bmim]BF4 aqueous solutions at IL-mole fraction of 0.20.     

Effects of imidazolium-based ionic liquids on the isobaric vapor–liquid equilibria of methanol + dimethyl carbonate azeotropic systems

The separation of methanol(MeOH) and dimethyl carbonate(DMC) is important but difficult due to the formation of an azeotropic mixture. In this work, isobaric vapor–liquid equilibrium(VLE) data for the ternary systems containing different imidazolium–based ionic liquids(ILs), i.e. MeOH + DMC + 1-butyl-3-methy-limidazolium bis[(trifluoromethyl)sulfonyl]imide([Bmim][Tf_2N]), MeOH + DMC + 1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide([Emim][Tf_2N]), and MeOH + DMC + 1-ethyl-3-methylimidazolium hexafluorophosphate([Emim][PF6])) were measured at 101.3 kPa. The mole fraction of IL was varied from0.05 to 0.20. The experimental data were correlated with the NRTL and Wilson equations, respectively. The results show that imidazolium-based ILs were beneficial to improve the relative volatility of MeOH to DMC,and [Bmim][Tf_2 N] showed a much more excellent performance on the activity coefficient of MeOH. The interaction energies of system components were calculated using Gaussian program, and the effects of cation and anion on the separation coefficient of the azeotropic system were discussed.     

水-乙醇-1-丁基-3-甲基咪唑乙酸盐三元体系汽液平衡测定及模型

Vapor-liquid equilibrium (VLE) data were measured for ternary system water + ethanol + 1-butyl-3- methylimidazolium acetate ([bmim][OAc]), in a relatively wide range of ionic liquid (IL) mass fractions up to 0.8. Six sets of complete T-x-y data were obtained, in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and approximate 0.98. The non-random-two-liquid (NRTL) and electrolyte non-random-two-liquid (eNRTL) equations were used for correlation, showing similar deviations. The ternary VLE was also modeled with the correlation from two data sets, with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98. The VLE data were also reproduced satisfactorily. With the eNRTL model, the root-mean-square deviation for temperature is 0.79 K and that for vapor-phase mole fraction is 0.0094. The calculations are in good agreement with experimental data. The effect of the IL on the VLE behavior of the volatile components is also illustrated.     

Effect of methylimidazolium-based ionic liquids on vapor–liquid equilibrium behavior of tert-butyl alcohol + water azeotropic mixture at 101.3 kPa

Three ionic liquids(ILs),1-ethyl-3-methylimidazolium bromine([EMIM]Br),1-butyl-3-methylimidazolium bromine([BMIM]Br),and 1-hexyl-3-methylimidazolium bromine([HMIM]Br),were used as the solvent for separation of {tert-butyl alcohol(TBA)+ water} azeotrope.Vapor–liquid equilibrium(VLE)data for {TBA + water + IL}ternary systems were measured at 101.3 k Pa.The results indicate that all the three ILs produce an obvious effect on the VLE behavior of {TBA + water} system and eliminate the azeotropy in the whole concentration range.[EMIM]Br is the best solvent for the separation of {TBA + water} system by extractive distillation among the three ILs.The experimental VLE data for the ternary systems are correlated with the NRTL model equation with good correlations.Explanations are given with activity coefficients of water and TBA,and the experimental VLE-temperature data for {TBA or water + IL} binary systems.     

Isobaric vapor–liquid equilibrium for binary system of aniline+methyl-N-phenyl carbamate

In this study,the quasi-static ebulliometric method was used to measure both of the vapor pressures of methyl N-phenyl carbamate(MPC),and the isobaric vapor–liquid equilibrium(VLE) data of the aniline and MPC binary system.The measured vapor pressure data of MPC,at different temperature ranging from 369.60 to 389.54 K,fitted well with the Antoine equation.The VLE data for the aniline and MPC system at(2.00,4.00,6.00,7.00 and 8.00) k Pa were correlated by both of nonrandom two-liquid(NRTL) and Wilson models.The parameters of the two models were obtained by regressing the experimental data,with the absolute temperature deviations of 0.54 K and 0.53 K,respectively.The relative volatility of the binary system calculated was all far more than 1,which gives the conclusion that the high purity MPC can be separated from aniline and MPC binary system by rectification or distillation technology.     

甲基二氯硅烷-甲基乙烯基二氯硅烷-甲苯三元体系等压汽液平衡

Vapor-liquid euilibrium (VLE) for a ternary system of Methyldichlorosilane methylvinyldichlorosilane toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer,The equilibrium conpositions of the vapor phase of binary systems were calculated indirectly from the total pressure-temperature-liquid composition(pTx).The experimental data were correlated with the Wilson and NRTL(non-random two liquid )equations.The parameters of the Wilson moldel were employed to predict the ternary VLE data .The calculated boiling points were in good agreement with the experimental ones.     

醋酸脱水过程中对二甲苯+(醋酸,醋酸甲酯,醋酸正丙酯)和醋酸甲酯+醋酸正丙酯的二元汽液相平衡(英文)

The vapor-liquid equilibrium data of four binary systems (acetic acid +p-xylene, methyl acetate +n-propyl acetate, n-propyl acetate +p-xylene and methyl acetate +p-xylene) are measured at 101.33 kPa with Ellis equilibrium still, and then both the NRTL and UNIQUAC models are used in combination with the HOC model for correlating and estimating the vapor-liquid equilibrium of these four binary systems. The estimated binary VLE results using correlated parameters agree well with the measured data except the methyl acetate +p-xylene system which easily causes bumping and liquid rushing out of the sampling tap due to their dramatically different boiling points. The correlation results by NRTL and UNIQUAC models have little difference on the average absolute deviations of temperature and composition of vapor phase, and the results by NRTL model are slightly better than those by UNIQUAC model except for the methyl acetate +n-propyl acetate system, for which the latter gives more accurate correlations.     

LiBr-[BMIM]Cl/H2O工质对的饱和蒸气压、结晶温度和腐蚀性

为了解决LiBr/H₂O工质对易结晶和腐蚀性强的问题,提出了LiBr-[BMIM]Cl/H₂O和LiBr-[BMIM]Br/H₂O新型工质对,研究了离子液体 [BMIM]Cl和[BMIM]Br对LiBr/H₂O结晶温度和饱和蒸气压的影响。对质量比为2.5的LiBr-IL(ionic liquids)/H₂O的饱和蒸气压、结晶温度和腐蚀性进行了测定并与LiBr/H₂O的进行了比较,结果表明[BMIM]Cl/H₂O和[BMIM]Br/H₂O的饱和蒸气压与质量分数低8%~9%的LiBr/H₂O的饱和蒸气压基本相同。在常用工作浓度范围内,LiBr-[BMIM]Cl/H₂O的结晶温度比相同吸收能力的LiBr/H₂O的低约30℃。在相同的腐蚀条件下,LiBr-[BMIM]Cl/H₂O对碳钢的腐蚀性明显小于LiBr/H₂O,对紫铜的腐蚀性与LiBr/H₂O的基本相同。因此,采用LiBr-[BMIM]Cl/H₂O作为替代工质对具有一定的应用潜力。     

Vapor pressure measurement and correlation of acetonitrile+1-butyl-3-methylimidazolium chloride,+1-butyl-3-methylimidazolium tetrafluoroborate,and+1-hexyl-3-methylimidazolium chloride

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ...     

带共沸的乙醇/乙酸乙酯/2-丁酮三元物系变压精馏分离过程及其参数优化

提出了一种带两股循环的三塔变压精馏结构用于分离乙醇（C₂H₅OH）/乙酸乙酯（C₄H₈O₂-3）/2-丁酮（C₄H₈O-3）三元混合物。由该三元混合物的剩余曲线图（RCM）可知,在大气压下该混合物的每一对组元均形成二元最低共沸物,且乙醇/乙酸乙酯二元共沸物组成随压力变化敏感。三个最低共沸物的同时存在形成了精馏边界线夹紧点现象,而通常压力下的精馏塔无法跨越,以至于传统变压精馏无法应用。通过对精馏塔压力的最优化克服了这一困难,提出了新的分离流程,并对过程进行严格稳态模拟。针对初分塔（T1）塔压不同的6种流程,采用序贯迭代法对各塔的塔板数、进料板位置、回流比等参数进行了优化。通过对比6种流程的经济评价和比较,得到了T1塔的最优压力,并经过能量集成使得过程的年度总费用降低了14.88%。     

Preparation of multi-compositional gas sensing films by combinatorial solution deposition

Various compositions of gas sensing films were prepared by the combinatorial deposition of SnO₂, ZnO, and WO₃ sol solutions and their gas sensing behaviors were investigated. The film composition could be manipulated conveniently via the alternate dropping of different oxide sol solutions. From the correlation between film compositions and gas sensitivities, the selective detection of C₂H₅OH and CH₃COCH₃ in the presence of CO, C₃H₈, H₂, and NO₂ could be attained. In addition, the discrimination between C₂H₅OH and CH₃COCH₃, which is a challenging issue due to their similar chemical nature, becomes possible. This research demonstrates the precise design of the sensor-material composition for the selective gas detection via the combinatorial approach.     

醚基功能化离子液体催化合成乙酸正丁酯

合成了5种醚基功能化酸性离子液体[Me（OEt）₁-MOR-C₃SO₃H][MeSO₃]、[Me（OEt）₂-MOR-C₃SO₃H][MeSO₃]、[Me（OEt）₃-MOR-C₃SO₃H][MeSO₃]、[2（C₃SO₃H-MOR）-（OEt）₂₀₀][2MeSO₃]、[2（C₃SO₃H-MOR）-（OEt）₄₀₀][2MeSO₃],使用红外光谱和核磁共振氢谱对合成的离子液体结构进行表征,考察离子液体的黏度、溶解性和腐蚀性。以正丁醇和乙酸的酯化反应考察了离子液体的催化活性,并使用响应面分析法优化反应工艺。结果表明,当酸醇摩尔比为1.2：1、催化剂[2（C₃SO₃H-MOR）-（OEt）₄₀₀][2MeSO₃]用量为醇质量的5%、带水剂用量为醇质量的16%时,在90℃下反应5 h,酯收率可达97.8%,离子液体经回收干燥重复使用8次催化活性没有明显的降低。     

L-精氨酸衍生物的合成及其性质研究

以L-精氨酸(L-Arginine)和香兰素(Vanillin)为原料,首先合成新型的具有手性的希夫碱配体L(C_(14)H_(14)KN_3O_4),其次配体L分别与金属盐(CH_3COO)_2Ni·2H_2O、BaCl_2、(CH_3COO)_2Zn·2H_2O进行配位反应,得到3种新型的金属配合物(C_(16)H_(19)ZnKN_3O_7、C_(14)H_(14)BaClKN_3O_4和C_(18)H_(20)KN_3NiO_8),目标产物用IR、荧光分光光度计和元素分析仪等表征其结构,并用紫外漫反射光谱在可见光照射下,考察了配体L和3种新型的金属配位化合物的催化性能。实验结果推测配体L和L金属配合物均具有光催化性质,L金属配合物的催化性能更强。     

低黏二氰胺类离子液体乙烯汽液相平衡研究

从工业废气中回收分离乙烯（C₂H₄）具有重要意义,选用了三种低黏度二氰胺类离子液体,分别测定了293.15~333.15 K下其密度、黏度等物化性质,研究了其对乙烯（C₂H₄）吸收性能。采用非随机（局部）双液体模型（NRTL）关联了三种二元体系溶解度数据,实验值与计算值的平均相对偏差均小于3%。结果表明,低黏度二氰胺类离子液体对C₂H₄气体吸收性能良好,其中阳离子侧链长度增加和羟基功能团引入可增强对C₂H₄溶解度。同时,离子液体1-丁基-3-甲基咪唑二氰胺盐（[Bmim][DCN]）经过3次的吸收解吸循环,仍可以保持较好的C₂H₄吸收性能,表明该离子液体循环稳定性好,而1-丁基-3-甲基咪唑二氰胺盐（[Bmim][DCN]）对乙烯吸收量较高,具有作为C₂H₄吸收剂的潜力。     

Chemistry of surface oxygen formed from N2O on ZSM-5 at moderate temperatures

Conversion of CH₄, C₂H₆, C₃H₈, benzene and their binary mixtures over H-NaZSM-5 catalyst in the presence of N₂O was studied. It was found that under experimental conditions methane alkylates benzene to give toluene and xylenes. Acidity of the catalyst had no effect on the reactivity of active oxygen formed from N₂O towards methane and benzene, but affected their secondary transformation. Acidic samples favored the reaction of aromatic ring methylation with methane whereas deep oxidation of CH₄ prevailed on NaHZSM-5. Based on the relative reactivities and ¹³C label distribution in the products of ¹³CH₄+C₆H₆+N₂O feed conversion, the scheme of hydrocarbon transformation was proposed.