苯-噻吩-二甲基亚砜体系等压汽液相平衡研究

采用汽液双循环相平衡仪测定了101.33 k Pa下苯-噻吩、苯-二甲基亚砜及苯-噻吩-二甲基亚砜的等压汽液相平衡数据。两组二元体系实验数据均通过了Herington面积法的热力学一致性检验,分别采用NRTL和UNIQUAC活度系数模型对二元体系实验数据进行热力学关联,得到了相应的模型参数,温度偏差和汽相组成偏差,关联结果表明两种模型均能较好的关联实验数据,其中UNIQUAC模型的关联结果稍优于NRTL。利用二元体系UNIQUAC模型参数预测三元体系汽液平衡数据,预测值与实验值相比,平均温度偏差1.37 K,汽相各组分平均绝对偏差均在3%以内,获得了较优的预测结果,从而为工业上苯-噻吩萃取精馏分离过程提供可靠的热力学基础数据。     

水-二乙氧基甲烷-乙苯/苯甲醚的液液相平衡

为了探索不同萃取剂萃取分离水-二乙氧基甲烷共沸物的能力,在大气压力下,以乙苯和苯甲醚为萃取剂,分别测定了303.15和313.15 K时水-二乙氧基甲烷-乙苯/苯甲醚体系的液液相平衡数据。通过计算所得分离因子远大于1,表明乙苯和苯甲醚均为此体系的优良萃取剂。使用Othmer-Tobias和Hand经验方程对实验数据进行了一致性检验,其线性相关系数R~2均大于0.99。利用NRTL和UNIQUAC热力学模型对实验数据进行关联,相对均方根偏差(RMSD)均小于0.006,表明NRTL和UNIQUAC可以很好地关联实验数据。     

水-乙醇-甲基异丁基甲酮体系液液相平衡数据的测定与关联

在常压下测定了水-乙醇-甲基异丁基甲酮体系在308.15,318.15,328.15 K的液液相平衡数据。用Hand方程和Othmer-Tobias方程对实验数据进行拟合,结果表明:Hand方程拟合效果优于Othmer-Tobias方程。采用NRTL模型和UNIQUAC模型对实验数据进行了关联,回归得到了该三元物系的二元交互参数;并对此物系的相平衡数据进行了预测,由模型计算值和实验值的均方根偏差知,NRTL模型能更好地与实验数据吻合。     

水-二乙氧基甲烷-萃取剂的液液相平衡研究

为了给水-二乙氧基甲烷共沸物的分离提供数据支撑,探讨了101.3 kPa下303.15,313.15,323.15 K时三元体系水-二乙氧基甲烷-甲基叔丁基醚/甲基异丁基酮的液液相平衡数据。根据实验数据对分配系数和分离因子进行了估算,其值均大于1,表明MTBE和MIBK作为萃取剂具有较好的萃取能力和较高的选择性;使用Othmer-Tobias和Bachman经验方程来检验实验数据的一致性,其线性相关R~2≥0.99;利用NRTL和UNIQUAC热力学模型对实验数据进行关联,相对均方根偏差(RMSD)和平均相对偏差(ARD)均低于0.003,表明NRTL和UNIQUAC都能很好地关联实验数据。     

甲基叔丁基醚-丙酸-丁酸-水四元体系液液相平衡的测定与关联

二元交互作用参数是萃取分离过程模拟和设计的关键数据,它通常是通过液液相平衡测定的数据回归得到。在常压下测定了25℃时甲基叔丁基醚-丙酸-丁酸-水四元体系液液相平衡数据,用NRTL和UNIQUAC模型对所测实验数据进行热力学关联,采用Bachman、Othmer-Tobias和Hand公式验证了数据的可靠性状况,利用模拟软件回归得到二元交互作用参数。结果表明,基于NRTL和UNIQUAC模型关联计算得到的计算值与实验值吻合良好,两种模型计算的相对均方根偏差分别小于0.0122和0.0184,说明两个模型回归得到的二元交互作用参数均能对实验液液相平衡数据进行很精确地预测。     

甲基戊烯酮-水-邻苯二酚三元物系液液相平衡数据的测定与关联

为了给甲基戊烯酮萃取脱酚过程的设计和开发提供数据支撑,采用液液平衡釜分别测出常压下30、40和50℃甲基戊烯酮-水-邻苯二酚体系的液液相平衡组成,并通过Hand方程、Bachman方程对结果进行可靠性检验,其相关性系数的平方均大于0.99。同时利用Aspen Plus软件选取NRTL模型对实验数据进行关联,得到该三元物系相应的热力学模型参数,并以此计算相应的相平衡组成,与实验数据对比两者间的相对均方根误差和绝对平均误差均为1%。因此,NRTL模型及其参数可准确描述该物系的相平衡行为。     

甲基戊烯酮-水-邻苯二酚三元物系液液相平衡数据的测定与关联

为了给甲基戊烯酮萃取脱酚过程的设计和开发提供数据支撑,采用液液平衡釜分别测出常压下30、40和50℃甲基戊烯酮-水-邻苯二酚体系的液液相平衡组成,并通过Hand方程、Bachman方程对结果进行可靠性检验,其相关性系数的平方均大于0.99。同时利用Aspen Plus软件选取NRTL模型对实验数据进行关联,得到该三元物系相应的热力学模型参数,并以此计算相应的相平衡组成,与实验数据对比两者间的相对均方根误差和绝对平均误差均为1%。因此,NRTL模型及其参数可准确描述该物系的相平衡行为。     

水-仲丁醇-乙酸仲丁酯三元体系的液液相平衡研究

测定了水-仲丁醇-乙酸仲丁酯三元体系在303.15,323.15,343.15,353.15 K下的液液相平衡数据,并用NRTL模型和UNIQUAC模型对相平衡数据进行关联,应用单纯形法求得相应的模型参数。计算值与实验值比较结果表明:NRTL模型与UNIQUAC模型的计算值与实验数据吻合良好。     

水-醋酸-醋酸正丁酯三元体系液液平衡研究

文章用液液平衡装置在常压下，测定了水．醋酸-醋酸正丁酯三元体系40℃的液液相平衡数据。运用Othmer-Tobias方法对系线组成进行关联。由实验数据回归确定了NRTL、UNIQUAC以及修正的UNIFAC活度系数模型参数，并运用这些模型对体系相平衡进行了预测。将实验数据与关联结果比较，结果表明，三种方程均能较好地对溶液组成进行预测，其中UNIQUAC方程的拟合精度最好。     

正十二烷-甲苯-苯酚三元体系液液相平衡数据的测定与关联

为获得研究中低温煤焦油典型组分之间的溶解特性以及指导煤焦油中酚类化合物提取所需的基础数据,在常压下测定了正十二烷-甲苯-苯酚三元体系在303.15、323.15和353.15 K时的液液相平衡数据,得到该体系三元相图。采用Othmer-Tobias方程对不同温度下的相平衡数据进行可靠性检验,相关性系数在0.992以上,表明实验数据可靠性较好,选取NRTL和UNIQUAC模型对所得液液平衡数据进行关联,获得了不同温度下模型参数,计算值与实验值比较表明:NTRL和UNIQUAC模型的计算值与实验值吻合良好,其相对均方根偏差均在1%以内。     

甲基异丙基甲酮-苯酚-对苯二酚-水的液液相平衡数据测定、模型关联及萃取过程模拟

液液相平衡测定为溶剂萃取及回收的准确模拟、设计和过程开发提供基础数据。以甲基异丙基甲酮为萃取剂,在处理高浓煤化工含酚废水的三元液液相平衡萃取基础上,选定其中典型单元酚苯酚和多元酚对苯二酚为代表物,测定甲基异丙基甲酮-苯酚-对苯二酚-水在常压40℃下的液液相平衡数据。采用NRTL和UNIQUAC活度系数模型对实验数据进行热力学关联,回归得到该四元体系的二元交互作用参数。结果表明该模型可以很好地关联实验数据,两种模型的相对均方根偏差分别小于0.190%和0.266%。进一步将得到的二元交互参数导入流程模拟系统,对萃取单元模块进行计算。当萃取温度40℃、萃取级数5级、相比1：7.72时,甲基异丙基甲酮能将总酚12700 mg×L^-1,多元酚4250 mg×L^-1的含酚废水的酚浓度分别降低至300 mg×L^-1和299 mg×L^-1以下。     

水-丙烯酸-醋酸-甲苯四元体系液液平衡数据的测定与关联

采用液液平衡釜,在常压下,测定了293.15,303.15,313.15 K时水-丙烯酸-醋酸-甲苯四元体系的液液平衡数据,为萃取-非均相共沸精馏法精制丙烯酸选择适宜的溶剂提供依据.使用Othmer-Tobias方程对实验数据进行线性拟合.分别采用非随机双液(NRTL)和通用似化学(UNlQUAC)活度系数模型对实验体...     

水-甲基叔丁基醚-二异丙醚三元体系液液相平衡的研究

在常压下测定了不同温度时水-甲基叔丁基醚-二异丙醚三元体系的液液平衡,并用Modified UNIQUAC模型和Extended UNIQUAC模型对所测体系进行了关联计算．Modified UNIQUAC模型的计算结果与实验数据的关联性更好。     

丁酮-水-丙三醇三元体系液液平衡数据的测定与关联

为了给以丙三醇为溶剂萃取分离丁酮-水体系的过程设计和流程模拟计算提供基础数据,在常压,20,40,60℃下,测定了丁酮-水-丙三醇三元体系的液液平衡数据,得到了三元体系的共轭相组成并由此绘得相平衡曲线。实验数据用UNIQUAC和NRTL模型进行了关联,利用关联出的模型参数计算了相应的液相组成,并与实验值比较,其平均偏差小于0.003 8,计算值与实验数据吻合良好。求得了溶剂对溶质的选择性系数,验证了丙三醇是液液萃取分离丁酮-水的良好溶剂。     

Tie-line data for aqueous mixtures of butyric acid with isobutyl acetate at various temperatures

Experimental liquid-liquid equilibrium (LLE) data for the system of (water+butyric acid+iso-butyl acetate) were obtained at T=(298.2, 303.2, 308.2, and 313.2) K and atmospheric pressure. This ternary system exhibits type-1 behavior of LLE. The experimental tie-line data were correlated using the UNIQUAC and NRTL models. The reliability of the experimental tie-line data was determined by applying the Othmer-Tobias and Hand correlations. Distribution coefficients and separation factors were calculated over the immiscibility regions.     

Application of UNIQUAC and SVM to ultrafiltration for modeling ternary mixtures of oil, FAME and methanol

To describe a membrane separator for ternary mixtures of oil-FAME-MeOH, two models of UNIQUAC and support vector machine (SVM) are developed for the permeate composition and permeate flux, respectively. The UNIQUAC model is used to represent the liquid-liquid phase equilibrium of oil-FAME-MeOH. Its prediction results are consistent with the experimental data measured at the temperatures of 293, 313 and 333 K, respectively. For this two-phase system, experimental results show that the oil-rich phase can be rejected by the ceramic membrane while the methanol-rich phase permeates through the membrane. The permeate composition is mainly determined by the feed bulk concentration, and therefore is consistent with the concentration of the methanol-rich phase predicted by the UNIQUAC model. On the other hand, the permeate flux under various operating conditions, such as feed concentrations, temperatures, inlet flow rates and transmembrane pressures, is modeled by the SVM algorithm. Unlike the general data-based neural network model, SVM is especially valuable in the present crossflow filtration problem of small sample sizes. By combining UNIQUAC and SVM with the experimental ultrafiltration of biodiesel mixtures, the predicted membrane separator performance shows no significant lack of fit, and continuous production of biodiesel with both high purity and maximal productivity is also discussed.     

二乙氧基甲烷-乙醇-水-甘油体系部分组分液液平衡

用液液平衡釜测定了二乙氧基甲烷-水、二乙氧基甲烷-甘油2组二元和二乙氧基甲烷-水-甘油、二乙氧基甲烷-乙醇-甘油、二乙氧基甲烷-水-乙醇3组三元体系常温、常压下的液液平衡数据。用NRTL和UNIQUAC方程对所测二元体系的平衡数据进行了处理。采用单参数法关联了乙醇-甘油体系的模型参数。结合三元体系的液液平衡数据,用NRTL和UNIQUAC方程关联出了三元体系中的第3对模型参数。确定了二乙氧基甲烷-乙醇-水-甘油体系合适的模型及参数,为含二乙氧基甲烷体系的实际分离过程提供了依据。     

LIQUID-LIQUID EQUILIBRIA OF ORGANIC COMPOUNDS: MEASUREMENT, CORRELATION AND PREDICTION†

The knowledge of phase equilibria is an important step in the development of extraction processes. This knowledge is usually gained from experiments. However, this procedure is expensive when a suitable solvent has to be found for a specific separation. Therefore methods for predicting phase equilibria are needed. While formerly these methods were largely based on empirical assumptions, the use of the concept of local compositions by Wilson⁶ offers a semi-empirical approach.

There is one disadvantage of this approach: the parameters of models like UNIQUAC or NRTL have to be fitted to different types of data, to liquid-liquid equilibria (LLE) for the immiscible pairs of components and to vapour-liquid equilibria (VLE) or other data for the miscible pairs in a system with mutual solubility.

To demonstrate the problem we performed measurements in the binary systems: n-octane/aniline and methylcylohexane/aniline. of both liquid-liquid equilibrium and vapour-liquid equilibrium: for the second type of measurements ebulliomeiry was used. The prediction of LLE has been improved with two new concepts. One is based on the well-known UNIFAC method. The use of the Lyngby-Dorlmund data bank made it possible to determine a new parameter table merely based on LLE data.

The second method is based on common UNIQUAC parameters which have been determined with the data base.     

On the concentration dependence of the UNIQUAC/UNIFAC models

The UNIQUAC/UNIFAC models can not in general represent vapor-liquid and liquid-liquid equilibria simultaneously with satisfactory results. Recent modifications of the models take into account association and solvation effects by means of chemical theory. However, this approach leads to complicated expressions for the activity coefficients and the improvements are only moderate. A modification of the UNIQUAC/UNIFAC models is presented which takes into account solvation and association by allowing the interaction energies to vary with composition. This approach leads to explicit expressions for the activity coefficients. It is shown that the modified models in simultaneous correlations lead to quantitative representation of vapor-liquid equilibrium data and semi-quantitative representation of binary and ternary liquid-liquid equilibrium data.     

LIQUID-LIQUID EQUILIBRIA OF ORGANIC COMPOUNDS: MEASUREMENT,CORRELATION AND PREDICTION†

The knowledge of phase equilibria is an important step in the development of extraction processes. This knowledge is usually gained from experiments. However, this procedure is expensive when a suitable solvent has to be found for a specific separation. Therefore methods for predicting phase equilibria are needed. While formerly these methods were largely based on empirical assumptions, the use of the concept of local compositions by Wilson⁶ offers a semi-empirical approach.

There is one disadvantage of this approach: the parameters of models like UNIQUAC or NRTL have to be fitted to different types of data, to liquid-liquid equilibria (LLE) for the immiscible pairs of components and to vapour-liquid equilibria (VLE) or other data for the miscible pairs in a system with mutual solubility.

To demonstrate the problem we performed measurements in the binary systems: n-octane/aniline and methylcylohexane/aniline. of both liquid-liquid equilibrium and vapour-liquid equilibrium: for the second type of measurements ebulliomeiry was used. The prediction of LLE has been improved with two new concepts. One is based on the well-known UNIFAC method. The use of the Lyngby-Dorlmund data bank made it possible to determine a new parameter table merely based on LLE data.

The second method is based on common UNIQUAC parameters which have been determined with the data base.