Liquid-Liquid Equilibrium for 1-Butanol-Water-KF and 1-Butanol-Water-K_2CO_3 Systems

KF or K2CO3 was added into the 1-butanol-water system and two phases were formed： water-rich phase （water phase） and 1-butanol-rich phase （1-butanol phase）. The liquid liquid equilibrium （LLE） data for 1-butanol-water-KF and 1-butanol-water-K2CO3 systems were measured at 25℃ and showed that 1-butanol phase contained negligible salt and water phase contained negligible 1-butanol when the concentrations of KF and K2CO3 in the water phase were equal to or higher than 27.11% and 31.68% , respectively. Thus water could be separated efficiently from 1-butanol-water by adding KF or K2CO3 into the system. A theoretical calculation of LLE data was calculated by using the Pitzer theory to get water activity in the water phase, and by the models, such as the Wilson, NRTL or the UNIQUAC for the 1-butanol phase. For 1-hutanol-water-KF system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and Wilson equa tion, while for 1-butanol-water-K2CO3 system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and UNIQUAC eauation.

Salt effect on the liquid–liquid equilibrium of the ternary (water + phenol + methyl isobutyl ketone) system: Experimental data and correlation

The effects of NaCl, KCl and Na_2SO_4 on the liquid–liquid equilibrium(LLE) data for the ternary system, water+ phenol + methyl isobutyl ketone, were determined at 0.101 MPa and 333.15 K and 343.15 K.The nonrandom two-liquid(NRTL) model was used to correlate the experimental data and to yield corresponding binary interaction parameters for these salt containing systems.The Hand and Othmer–Tobias equations were used to confirm the dependability of the determined LLE data in this work.Distribution coefficient and selectivity were used to evaluate the extraction performance of methyl isobutyl ketone with the existence of salt.The magnitude of salt effect on the water + phenol + methyl isobutyl ketone(MIBK) system is in the following order: Na_2SO_4>NaCl>KCl.

Measurements and correlation of liquid–liquid equilibrium data for the ternary(methyl tert-butyl ketone + o, m, p-benzenediol + water)system at(333.2, 343.2 and 353.2) K

In this work, liquid–liquid equilibria(LLE) data for the ternary system methyl tert-butyl ketone(MTBK)+ o, m,p-benzenediol + water were investigated at 333.2 K, 343.2 K and 353.2 K under 101.3 kPa. The performance of MTBK to extract o, m, p-benzenediol from wastewaters was estimated by partition coefficients and separation factors. The Hand and Bachman equations were both applied to check the reliability of the experimental LLE data. Furthermore, the Non-Random Two-Liquid(NRTL) and Universal Quasi Chemical(UNIQUAC) models were applied to correlate the measured LLE data. The results showed a good agreement with the determined ternary LLE data with the root-mean-square error(RMSE) values below 0.71%. MTBK was proved to be a promising extracting agent in extracting benzenediols from effluents.

Investigation of liquid–liquid equilibrium of the ternary system(water +1,6-diaminohexane + 2-methyl-1-propanol or 3-methyl-1-butanol) at different temperatures

In this study, the LLE data of ternary system(water + 1,6-diaminohexane + 2-methyl-1-propanol) and(water +1,6-diaminohexane + 3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure. Reliability of the experimental tie-line data was checked by empirical Hand, Othmer-Tobias and Bachman equations. Distribution coefficient(D) and selectivity(S) were calculated in order to investigate capability of the studied organic solvents for 1,6-diaminohexane extraction. The high values of separation factors demonstrated that 2-methyl-1-propanol and 3-methyl-1-butanol were applicable for this purpose. The experimental data were correlated by nonrandom two-liquid(NRTL) and universal quasi-chemical(UNIQUAC) models.The percent-root-mean-square deviation(RMSD) values for NRTL and UNIQUAC models were less than 0.15,which indicated that the experimental data have been sufficiently correlated.

Salting-out effect of ionic liquids on isobaric vapor-liquid equilibrium of acetonitrile-water system

This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the VLE data for the acetonitrile + water + ILs systems are correlated by salt effect models, Furter model and improved Furter model. The overall average relative deviation of Furter model and improved Furter model is 5.43% and 4.68%, respectively. Thus the salt effect models are applicable for the correlation of IL containing systems. The salting-out effect theory can be used to explain the change of relative volatility of acetonitrile–water system.

Separation of n-heptane and tert-butanol by ionic liquids based on COSMO-SAC model

In the process of liquid-liquid extraction,it is necessary to look for green solvents as extractants.Ionic liquids have been studied as extractants due to their green recyclability in recent years.The infinite dilution activity coefficients of 100 ionic liquids with a combination of 10 cations and 10 anions were calculated by COSMO-SAC model,and theσ-profiles were plotted.The distribution coefficient and separation coefficient of n-heptane+tert-butanol+ILs were determined.[OMIM][OTF],[HMIM][OTF]and[BMIM][OTF]were selected as solvents for this study.The interaction energy,bond length and charge density of ionic liquids with tert-butanol were calculated by quantum chemistry calculation method.According to these results,the rationality of selected ionic liquids as extractants could be analyzed from the molecular level.At 298.15 K and 101.325 kPa,the liquid-liquid equilibrium data of the ternary system{n-heptane+tert-butanol+[OMIM][OTF],nheptane+tert-butanol+[BMIM][OTF],n-heptane+tert-butanol+[HMIM][OTF]}were measured.The distribution coefficient and separation coefficient for judging the extraction effect were obtained.The NRTL model was used to correlate liquid-liquid equilibrium experimental data,and correlation result proved that the correlated and experimental data had a good correlation.The research on ionic liquids is of great significance to the development of green and sustainable chemical industry.

EXTENSION OF SOAVE EQUATION OF STATE TO LIQUID DENSITY

On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is proposed in this work. The VLE for 38 pure components including polar substances have been calculated. The comparison of calculated results with experimental data shows the prediction of liquid density is improved over Soave equation without losing the accuracy of prediction in vapor pressure and vapor density.

离子液体+正己烷+异丙醇液液相平衡数据的测定及关联

通过COSMO-RS模型筛选出1-乙基-3-甲基咪唑三氟乙酸盐([EMIM][TFA])、1-乙基-3-甲基咪唑二氰胺盐([EMIM][DCA])、1-乙基-3-甲基咪唑磷酸二乙酯([EMIM][DEP])三种离子液体作为萃取剂分离正己烷-异丙醇体系。在303.15 K、101.3 kPa下,测定正己烷+异丙醇+[EMIM][DCA]/[EMIM][TFA]/[EMIM][DEP]的三元液液相平衡实验数据,通过计算得出选择性与分配系数,分析离子液体各自的分离性能。通过Othmer-Tobias,Bachman,Hand方程对实验数据进行一致性检验。采用Aspen Plus v11流程模拟软件中NRTL模型进行数据关联拟合,获得均方根偏差(RMSD)和二元交互作用参数。模拟结果表明,选择性与分配系数均大于1,说明三种离子液体均可作为萃取剂;方程的回归系数均大于0.95,说明实验数据可靠;得到RMSD均小于3%,说明模拟计算数据能较好地关联实验数据。

甲基丙烯酸水溶液萃取分离液液相平衡数据测定与关联

针对甲基丙烯酸(MAA)与水(H_(2)O)形成共沸混合物、MAA水溶液分离难的问题,开展了MAA水溶液提纯过程萃取剂筛选、MAA H_(2)O萃取剂三元液液相平衡数据测定与关联等研究。通过对甲苯、正己烷、环己烷、邻苯二甲酸二丁酯(DBP)4种萃取剂的萃取效率进行考察,确定DBP为综合性能最优的萃取剂。测定了常压条件下20、30、40℃时H_(2)O MAA DBP三元体系的液液相平衡数据,实验结果通过了Hand方程和Othmer Tobias方程对相平衡数据的一致性验证,线性相关性系数R^(2)值超0.99。使用UNIQUAC模型来拟合实验数据得到三组分二元交互作用参数,模型预测值与实验值的均方根偏差小于0.07,表明实验数据及拟合参数均有较高的准确性,为DBP应用于工业MAA水溶液提纯过程开发提供基础。

液体复苏完成时间及液体负平衡量对脓毒性休克患者预后的影响

目的探究液体复苏完成时间及液体负平衡量对脓毒性休克患者预后的影响。方法选取2020年4月—2023年4月张家口市第一医院在重症科收治的脓毒症休克患者84例,予以30 mL/kg液体复苏治疗。分别根据液体复苏完成时间及液体负平衡量进行分组,记录患者的APACHEII评分、序贯器官衰竭评分(SOFA)、血乳酸、机械通气时间、连续性肾脏替代治疗占比、急性肾损伤发生率、急性呼吸窘迫综合征发生率、多器官功能障碍发生率及28 d病死率。结果不同时间完成液体复苏脓毒症患者的预后状况分析:1 h<T<3 h组患者液体复苏3 h后SOFA评分低于T≤1 h组、T≥3 h组(P<0.05)。各组患者的28 d病死率比较,1 h<T<3 h组患者的28 d病死率最低,T≤1 h组患者的28 d病死率最高,差异有统计学意义(P<0.05)。各组生存曲线分析比较,差异有统计学意义(P<0.05)。不同液体负平衡量脓毒症患者的预后状况分析:V<500 mL/24 h组患者液体复苏3 h后SOFA评分低于V≥500 mL/24 h组(P<0.05)。V<500 mL/24 h组患者的28 d病死率低于V≥500 mL/24 h组(P<0.05)。两组生存曲线分析比较,差异有统计学意义(P<0.05)。Cox回归分析显示,液体复苏3 h后SOFA评分、液体负平衡量、液体复苏完成时间是脓毒症休克患者预后生存的影响因素(P<0.05)。结论脓毒症休克患者在1~3 h内完成液体复苏,且液体复苏后维持<500 mL/24 h的液体负平衡量,有助于降低患者的28 d病死率。

基于流程模拟的固定床气化含酚废水有机萃取剂研究

为了对煤化工废水中的固定床气化含酚废水进行处理,研究提出对含酚废水的萃取脱酚流程进行模拟,并对液-液相平衡数据进行分析,最终得出最佳的萃取参数。实验表明,通过分析不同的温度等影响因素下萃取相参数,选取萃取等级为6,萃取相比例为1:3.5的萃取参数,得出总酚剩余的质量浓度为298 mg/L,萃取率为93.05%,单元酚的剩余质量浓度为75.1mg/L,萃取率为83.1%。可见研究基于萃取流程模拟对含酚废水脱酚萃取的有效性,为煤工厂含酚废水处理提供了技术支持。

离子液体吸收式制冷工质对气液相平衡研究及其分子动力学模拟

为了克服传统吸收式制冷工质对的种种缺陷,离子液体型制冷工质对被视作理想替代品,得到了广泛的开发与应用。采用静态实验和分子动力学模拟两种方法,对[EMIM]BF_(4)/CH_(3)OH离子液体二元体系的气液相平衡性质展开研究。研究结果显示,[EMIM]BF_(4)/CH_(3)OH离子液体二元溶液具有良好的气液相平衡性质,实验测得饱和蒸气压比其他醇类离子液体二元溶液低约21%;模拟结果与实验值有相同的数量级和变化趋势,相对误差普遍小于8%。研究结果为离子液体制冷工质对的筛选和进一步的理论循环系统研究提供了物性数据基础,另一方面也为离子液体基础物性研究提供了一种模拟预测的新方法。

Measurement and correlation of phase equilibrium data of the mixtures consisting of water, resorcinol, mesityl oxide at different temperatures

Liquid–liquid equilibrium(LLE) data were measured for the ternary system of water + resorcinol + mesityl oxide under atmospheric pressure at temperatures of(298.2, 323.2, 333.2, 343.2 and 353.2) K. The reliability of the experimental data was verified by the Hand and Bachman equations. The distribution coefficient and selectivity were calculated from the experimental LLE data, which showed high efficiency of mesityl oxide extracting resorcinol from the aqueous solution. The NRTL and UNIQUAC models were employed to fit the measured experimental LLE data and yield corresponding binary interaction parameters.

水+异戊醇+乳酸异戊酯三元液液相平衡的测定与关联

测定了常压下水+异戊醇+乳酸异戊酯三元混合体系在293.15 K、313.15 K、333.15 K温度下的液液相平衡数据,并与文献中已有的水+异戊醇二元液液相平衡数据进行比较,验证了测定方法的可靠性。利用Othmer–Tobias、Bachman和Hand方程验证了实验数据的可靠性。利用NRTL与UNIQUAC模型对数据进行关联,获得了模型的二元交互作用参数,关联结果与实验数据一致。

含硫酸氢盐离子液体的水+乙酸体系汽液平衡数据测定

为探究离子液体(ILs)作为催化剂对酯化反应精馏体系汽液平衡产生的影响,采用Dvorak-Boublik平衡釜测定了5种压力下水(1)+乙酸(2)二元体系的汽液平衡数据,并测定了不同压力和不同离子液体摩尔分数下的水(1)+乙酸(2)+1-磺酸丁基-2-甲基吡啶硫酸氢盐([HSO_(3)-BMPy][HSO_(4)])(3)三元体系的汽液平衡数据。通过COSMOlogic软件对[HSO_(3)-BMPy][HSO_(4)]几何结构进行优化,模拟获取屏蔽电荷密度图(σ-Profile)。结果表明,加入[HSO_(3)-BMPy][HSO_(4)]提高了二元体系的平衡温度,且对水的影响更大,减压使其平衡温度降低。[HSO_(3)-BMPy][HSO_(4)]易与水结合,使水与乙酸更难分离。测得的汽液平衡数据可为含[HSO_(3)-BMPy][HSO_(4)]体系的酯化反应精馏模拟计算提供热力学基础数据。

对二甲苯结晶相关多元体系的固液相平衡数据预测

针对与对二甲苯结晶相关的由苯、甲苯和碳八(C_(8))芳烃组分组成的多元体系,选取了固液相平衡计算模型—Van′t Hoff方程简式,利用由苯、甲苯和C_(8)芳烃组分组成的二元和三元体系固液相平衡文献值对模型进行考察,并利用该模型预测了对二甲苯-间二甲苯-邻二甲苯-乙苯四元体系、对二甲苯-间二甲苯-邻二甲苯-苯四元体系、对二甲苯-间二甲苯-邻二甲苯-乙苯-甲苯五元体系、对二甲苯-间二甲苯-邻二甲苯-乙苯-苯五元体系和对二甲苯-间二甲苯-邻二甲苯-乙苯-甲苯-苯六元体系,以及较低温度下对二甲苯-间二甲苯-邻二甲苯三元体系的固液相平衡数据。结果表明:采用Van′t Hoff方程简式计算,由苯、甲苯和C_(8)芳烃组分组成二元体系的液相摩尔分数的平均相对偏差为2.72%,低共熔点温度的偏差最高为0.59℃,最低为0.01℃,表明所选模型适用于由苯、甲苯和C_(8)芳烃组分组成的体系固液相平衡计算;利用Van′t Hoff方程简式预测的固液相平衡数据可为由苯、甲苯和C_(8)芳烃组分组成的体系固液相平衡数据测量和有关研究、设计、模拟优化提供理论指导。

离子液体-乙醇-庚烷液液相平衡数据的测定关联

文中采用平衡釜法测定在常压下温度为303.15 K时{[BMIM][TFA](一丁基三甲基咪唑三氟乙酸盐)、[BMIM][DCA](一丁基三甲基咪唑双氰胺盐)和[BMIM][SCN](一丁基三甲基咪唑硫氰酸盐)}+乙醇+庚烷三元体系的液液相平衡数据,使用Bachman方程和Othmer-Tobias方程对实验数据的热力学一致性进行检验,其线性相关系数均大于0.99。通过实验数据计算的分配系数和选择性比较了3种离子液体的分离性能,利用Aspen Plus v11模拟软件对实验数据回归得到二元相互作用参数,对比实验值得到的E_(RMSD)均小于4%。综上所述,使用离子液体萃取分离乙醇-庚烷体系是可行的,其中双氰胺根离子液体具有更好的探究价值。

以三丁基甲基醋酸铵为萃取剂萃取精馏分离乙酸乙酯-乙醇共沸物

以三丁基甲基醋酸铵([N_(4,4,4,1)][AC])为萃取剂,分离乙酸乙酯和乙醇的共沸体系。在101.3 kPa下测定了二元共沸体系(乙酸乙酯+乙醇)和三元体系(乙酸乙酯+乙醇+[N_(4,4,4,1)][AC])的气液相平衡数据。通过Aspen Plus软件中NRTL模型关联这些数据,发现当[N_(4,4,4,1)][AC]摩尔分数达到0.022时,系统不再共沸;以年化成本最小为要求对操作参数进行流程模拟优化,得到萃取精馏过程的最佳操作条件。

离子液体二元体系等压汽液相平衡的综合实验设计

为了让学生更好地理解非理想体系汽液相平衡的特点,基于学科前沿和研究基础,设计了乙醇-离子液体等压汽液相平衡测定的综合创新实验。该实验主要包括等压汽液相平衡的实验操作、非理想物系相平衡数据分析、阿贝折光仪分析样品含量、模型关联以及分子水平机理分析等,是一个涵盖了化工热力学、物理化学、物理光学、数值分析和量子化学等学科的综合实验。与传统二元体系汽液相平衡实验相比,该实验更具有探索性和创新性,操作简便省时,重复性高,提高了学生创新思维能力和科学研究意识,训练了学生发现问题和分析解决问题的综合能力。

Prediction of Liquid-Liquid Equilibrium Using the Group Solubility Parameter Model

The group solubility parameter （GSP） model was used to analyze the liquid-liquid equilibrium （LLE） of ternary and quaternary systems. The GSP parameters are divided into four dimensions representing the four major intermolecular forces. The values of the parameters were determined by regression using the nonlinear SIMPLEX optimization method to fit the LLE data of 548 ternary and 26 quaternary systems selected from the literature. LLE predictions of 8 ternary systems were then made using the fit parameters. Comparison of the results with predictions using the modified UNIFAC model shows that the GSP model has less adjustable parameters to achieve a similar accuracy and that the parameter values are easily acquired by analysis of available data.