丙酮、水、异丁醛的相平衡

本文测定了760毫米汞柱下丙酮-水-异丁醛体系的二元和三元的汽液平衡以及沸点下液液平衡数据,并用NRTL方程与多参数Wilson方程分别进行关联与计算,根据从二元体系的相平衡数据回归得到的三组二元参数来计算三元汽液平衡,均获得令人满意的一致结果。对于NRTL方程和多参数Wilson方程各建议了一套最佳的二元参数,可以满足设计丙酮-水-异丁醛分离设备的要求。     

常压下正丁醇-异丁醇-醋酸丁酯-水体系汽液平衡测定与关联

文章采用单级循环汽液平衡釜测定了常压条件下正丁醇-异丁醇-醋酸丁酯-水混合液中的二元体系的汽液平衡数据,运用试差法关联Wilson方程中六对二元体系的模型参数,并计算出相应的汽相组成;测定了常压条件下正丁醇-异丁醇-醋酸丁酯-水四元体系的汽液平衡数据,并由六对二元体系模型参数关联出四元体系的汽液平衡数据。比较实验和计算值,结果表明:实验值与计算值的相对偏差均≤5%,说明实验值与计算值一致。文章研究结果为正丁醇、异丁醇、醋酸丁酯及水混合液的分离提供了一定基础数据。     

沸点分析法在二元和三元体系汽液平衡测定中的应用

本文用沸点分析法测定了101.325kPa压力下,苯-甲苯二元体系和苯-甲苯-四氯化碳三元体系的汽液平衡数据。为了获得该三元体系的推算结果,同时又测定了苯-四氯化碳和甲苯-四氯化碳两组二元体系的汽液平衡数据,所有二元体系的汽液平衡数据用NRTL方程进行了热力学关联,并用获得的二元参数对三元体系的汽液平衡进行了预测,预测结果和实验结果符合良好。     

甲酸-水-甲酸戊酯体系的等压汽液平衡研究

用改进的Rose釜测定了101.325 kPa下甲酸-水、甲酸-甲酸戊酯、甲酸-水-甲酸戊酯体系的等压汽液平衡数据.考虑到甲酸在汽相中的缔合效应,用Hayden-O'connell关联式修正了汽相的非理想性,用非线性最小二乘法关联了甲酸-水和甲酸-甲酸戊酯体系的汽液平衡数据,获得了NRTL和UNIQUAC方程的模型参数.利用得到的二元体系NRTL模型参数,结合部分三元体系汽液平衡数据,关联得到水-甲酸戊酯体系的NRTL模型参数.由关联得到的三对二元NRTL模型参数预测部分三元体系汽液平衡数据,计算值与实验值基本吻合.     

四氢呋喃-甲苯-氟苯-水体系汽液平衡数据的测定和关联!

采用单级循环汽液平衡釜测定了常压下四氢呋喃-甲苯、四氢呋喃-氟苯、四氢呋喃-水、甲苯-氟苯、四氢呋喃-甲苯-水、四氢呋喃-氟苯-水和四氢呋喃-甲苯-氟苯-水体系的汽液平衡数据,采用Herington方法对二元汽液平衡数据进行热力学一致性校验;分别以NRTL和UNIQUAC方程为相平衡模型,通过化工辅助软件分别对二元、三元体系的汽液平衡数据进行关联,确定模型参数和相平衡模型;采用6对二元模型参数关联出四元体系的汽液平衡数据,并与实验值进行比较。结果表明:实验值与计算值的相对偏差均小于5%,说明实验与计算值一致。研究结果为四氢呋喃、甲苯、氟苯和水混合液的分离提供了一定基础数据。     

常压下叔丁醇-水-乙二醇体系汽液平衡测定与关联

在常压(101.3 kPa)下,采用改进的Othmer汽液平衡釜测定了叔丁醇-乙二醇体系的汽液平衡数据,对所测得的数据进行热力学一致性检验,结果表明实验数据符合热力学一致性。用NRTL模型对叔丁醇-乙二醇体系的汽液平衡数据进行关联,得到二元交互作用参数,并用这些参数计算汽相组成及平衡温度,计算结果与实验数据吻合。测定了叔丁醇-水-乙二醇三元体系的汽液平衡数据,乙二醇存在下,叔丁醇-水体系的相对挥发度大幅提高,证明乙二醇是萃取精馏分离叔丁醇-水体系的优良溶剂。     

3-羟基丁酸乙酯-巴豆酸乙酯-乙醇三元体系等压汽液平衡

在汽液双循环玻璃平衡釜中测定3-羟基丁酸乙酯、巴豆酸乙酯、乙醇的二元及三元体系的等压汽液平衡数据,用积分法对其进行了热力学一致性检验.回归实验数据得到3-羟基丁酸乙酯和巴豆酸乙酯的Antoine方程参数.用Wilson活度系数方程对实验数据进行了关联,取得了较好的结果.     

常压下丙酮-异丙醇-水体系汽液平衡测定与关联

采用单级循环汽液平衡装置测定了常压下丙酮-异丙醇-水体系中丙酮-异丙醇、丙酮-水、异丙醇-水二元及丙酮-异丙醇-水三元体系的汽液平衡数据,采用Herington方法对二元汽液平衡数据进行热力学一致性检验。分别以Wilson,NRTL及UNIQUAC为相平衡模型,采用最小方差法对二元汽液平衡数据进行关联,由关联的3对二元体系模型参数计算三元体系的汽液平衡数据,并与实验值进行比较。结果表明:计算值与实验值的相对偏差均≤5%,说明实验值与计算值一致,其中UNIQUAC模型误差较小。该结果为丙酮-异丙醇-水混合物的分离提供了一定基础数据。     

含缔合组分多元体系汽液平衡的研究及数理统计方法的应用(一)——甲酸-乙酸-水-乙酸甲酯四元体系汽液平衡的研究

本文解决了甲酸-乙酸-水-乙酸甲酯四元体系的分析方法,采用改进的Rose釜测定了这组体系在760mmHg下的互溶部分的汽液平衡数据。在二元缔合模型的基础上建立了一个含两个缔合组分的四元体系的热力学模型,分别用UNIQUAC方程[配位数Z=10及Z=Z(T)]、多参数Wilson方程、NRTL方程和Wilson方程从对应的六个二元体系汽液平衡数据关联所得的模型参数推算了四元体系的汽液平衡数据及对应的三元体系的汽液平衡数据,实验数据与推算结果的符合程度是令人满意的,尤其是Z=Z(T)的UNIQUAC方程的推算结果最好。     

丙酮-水-丙酮连氮体系汽液平衡测定与关联

采用汽液双循环平衡釜,在常压（101.3 kPa）下测定了丙酮-丙酮连氮二元组分物系以及部分丙酮-水-丙酮连氮三元组分物系的汽液平衡数据。实验数据经Herington面积积分法检验符合热力学一致性。通过化工过程模拟软件,分别采用Wilson、NRTL、UNIQUAC 活度系数模型对丙酮-丙酮连氮二元组分物系实验数据进行关联得到模型参数。并对汽液平衡的计算值与实验值进行比较,3种模型都吻合良好,其中由NRTL方程关联得到的计算结果最为适合,平均温度偏差和汽相组成偏差分别为0.0639 K和0.0048。从三元汽液相平衡数据中拟合出了丙酮-丙酮连氮、丙酮-水、水-丙酮连氮之间的NRTL方程相互作用参数。为验证数据及其二元相互作用参数的可靠性,利用关联出的丙酮-丙酮连氮模型参数计算出汽相组成与丙酮-丙酮连氮的二元数据比较,二者符合较好。实验和关联的结果为精馏分离丙酮-水-丙酮连氮汽液平衡体系提供了一定的基础数据。     

On the predictive capabilities of CPA for applications in the chemical industry: Multicomponent mixtures containing methyl-methacrylate,dimethyl-ether or acetic acid

The predictive performance of the CPA (Cubic-Plus-Association) equation of state for applications relevant to the chemical industry is illustrated in this work. Three such applications inspired by industrial requests/interest are illustrated here, all of which involve aqueous multicomponent mixtures exhibiting vapor–liquid (VLE) and/or liquid–liquid (LLE) equilibrium. The first two cases include mixtures of methyl-methacrylate with acetone or methanol and dimethyl-ether with ethanol, respectively. In these two cases, the classical form of CPA is used. The third case involves aqueous mixtures with acetic acid, esters, ethers and alcohols, and in this case for water–acetic acid the CPA-Huron Vidal (CPA-HV) version of the model is used. For the latter binary mixture, new CPA-HV binary parameter sets are estimated using, among others, data for activity coefficients at infinite dilutions. The modeling approach is similar in all three cases, i.e. the binary parameters are solely fitted to binary data and thus all multicomponent calculations are considered predictions.It is shown that CPA correlations for binary systems are excellent in all cases using temperature independent parameters except for the acetic acid–water system for which different parameter sets at different temperatures can be recommended. Even with the use of CPA-HV mixing rules, modeling of the acetic acid–water system with few interaction parameters remains a challenging task. Excellent simultaneous VLE and LLE correlation is obtained for complex systems such as aqueous mixtures with ethers and esters. The multicomponent results are, with a few exceptions, very satisfactory, especially for the vapor–liquid equilibrium cases. For the demanding aqueous acetic acid–water containing systems, one parameter set is recommended at the end for modeling ternary or multicomponent mixtures containing acetic acid and water.     

Solvent extraction of aromatics from middle distillates: Equilibria prediction method by group contribution

This work describes a method of calculating liquid-liquid aromatics extraction of a middle distillate. The group contribution models of the ASOG and UNIFAC type are investigated. Four vapour liquid equilibrium (VLE), two solid-liquid equilibrium (SLE), three binary and six ternary liquid-liquid equilibrium (LLE) have been measured. The parameters of the models are based mainly on the data of the systems having 10–20 carbon number. VLE, SLE, and infinite dilution activity coefficient data (17–245°C) have been used for calculating interaction parameters between hydrocarbon groups and LLE data (20–80°C) for interaction parameters of dimethylformamide-hydrocarbon groups. Middle distillate representation is based on mass spectrometric and gas chromatographic analysis and on limited data of middle distillate-DMF liquid-liquid equilibrium. It is shown that the performance of ASOG and UNIFAC models are sufficiently valid in representation of data base and in extraction calculations. Considering the predictive character and the rapidi of its application this method can be useful in the preliminary study of extraction processes.     

含辛烯醛体系的液液、汽液相平衡研究

测定了水-辛烯醛、水-正丁醇二元系在常压下的液液平衡数据及26.66kPa下的正丁醇-辛烯醛二元系和水-正丁醇-辛烯醛三元系的汽液平衡数据.由测定的3对二元数据求取了NRTL常数及有规参数,并与三元数据进行拟合,计算值与实验值符台良好,液液平衡与汽液平衡得到了统一的关联.     

马丁-侯(M-H)状态方程计算二元液液平衡

本文将马丁-侯状态方程用于LLE数据关联.对二元体系,使用两个二元相互作用参数.在较大温度范围,参数处理成温度函数;温度差范围在30-40℃之内,参数可作为常数,取得良好的关联结果.基于二元LLE数据推算了二元低压VLE,结果与实验值符合较好.     

CALCULATION OF VAPOR LIQUID EQUILIBRIUM AND EXCESS ENTHALPY WITH THE UNIQUAC EQUATION

The UNIQUAC equation was used for calculation of vapor liquid equilibrium (VLE)as well as excess enthalpy (h^E). Four sets of binary interaction parameters were applied: first, parameters estimated only from VLE data, then parameters from h^E data for both the original UNIQUAC equation and the Anderson modification, and finally parameters estimated from h^E and VLE data simultaneously. Calculations were performed for seven binary systems with polar components, representing different h^E behavior. The cross-prediction of h^E from VLE data works better than the reversed prediction. The model with parameters estimated simultaneously to both kinds of data can be applied successfully to both kinds of calculations, but it is a compromise between the models estimated from one kind of data.     

CALCULATION OF VAPOR LIQUID EQUILIBRIUM AND EXCESS ENTHALPY WITH THE UNIQUAC EQUATION

The UNIQUAC equation was used for calculation of vapor liquid equilibrium (VLE)as well as excess enthalpy (h^E). Four sets of binary interaction parameters were applied: first, parameters estimated only from VLE data, then parameters from h^E data for both the original UNIQUAC equation and the Anderson modification, and finally parameters estimated from h^E and VLE data simultaneously. Calculations were performed for seven binary systems with polar components, representing different h^E behavior. The cross-prediction of h^E from VLE data works better than the reversed prediction. The model with parameters estimated simultaneously to both kinds of data can be applied successfully to both kinds of calculations, but it is a compromise between the models estimated from one kind of data.     

Thermodynamics and separation process for quaternary acrylic systems

Vapor‐liquid equilibrium (VLE) and liquid‐liquid equilibrium (LLE) data of binary and ternary acrylic systems were systematically measured. Subsequently, VLLE phase diagrams of binary systems, tridimensional VLE phase diagrams of methyl acrylate (MA)‐methanol (Me)‐H₂O ternary system, and quaternary LLE phase diagrams of MA‐Me‐H₂O‐methyl acetate (MeOAc) system were constructed. These diagrams clearly demonstrated the effects of temperature on phase equilibrium. The experimental data was fitted by the NRTL and UNIQUAC models, and the best‐fitted parameters were used to predict interaction properties of ternary and quaternary mixture. Therefore, the phase equilibrium data were provided as reference for the design of acrylic systems rectification or extraction process. Residue curve was mapped out for MA‐Me‐H₂O system through Aspen plus software. Finally, using thermodynamics and residue curve as theoretical basis, two novel separation processes were proposed and applied to the quaternary acrylic systems. © 2015 American Institute of Chemical Engineers AIChE J, 62: 228–240, 2016     

碳酸二甲酯-碳酸二乙酯-甲醇三元体系相平衡数据的推算

采用双循环汽液平衡釜测定了常压下碳酸二甲酯-碳酸二乙酯、碳酸二甲酯-甲醇、碳酸二乙酯-甲醇三组二元体系的汽液平衡数据,实验数据经Herington面积积分法检验符合热力学一致性。用Wilson模型分别对实验数据进行了关联,利用关联出的模型参数计算相应的汽相组成,并与实验值比较,二者符合良好。利用二元体系的汽液平衡数据,由Wilson方程推算了碳酸二甲酯-碳酸二乙酯-甲醇三元体系的汽液平衡数据。为建立碳酸二乙酯和碳酸二甲酯、甲醇的精馏分离数学模型提供了基础数据。     

丙酮-乙酸异丙烯酯二元体系常压汽液平衡

用改进的埃利斯(Ellis)平衡蒸馏器测定了丙酮-乙酸异丙烯酯二元系统在常压下的汽液平衡数据,用液相活度模型Wilson、NRTL方程对测定数据进行关联,采用非线性最小二乘法回归出二元系统在常压下的Wilson、NRTL方程参数,Wilson模型与试验值符合良好.汽液相平衡数据经Herrington面积法检验满足热力学一致性.     

Application of UNIFAC models for prediction of vapor-liquid and liquid-liquid equilibria relevant to separation and purification processes of crude biodiesel fuel

Vapor-liquid equilibrium (VLE) of the methanol-biodiesel (BDF)/glycerin binary system and liquid-liquid equilibrium (LLE) of the water-BDF binary system and the methanol-BDF-glycerin and methanol-water-BDF ternary systems were predicted using several UNIFAC models: the latest original UNIFAC model, Kikic’s model, Fornari’s model, Dortmund-UNIFAC model, and LLE-UNIFAC model. The former VLE and latter LLE are used to design methanol recovery processes and separation and purification processes of crude BDF, respectively. Unfortunately, LLE data on the water-BDF binary system was not available. Instead, solubility of water in fatty acid methyl ester (one of the BDF constituents) was measured. By examining the deviation between predicted and experimental results, we determined which of the UNIFAC models was more useful for the design of those processes as follows: either the original UNIFAC model or Dortmund-UNIFAC model should be used for the methanol recovery process. The LLE-UNIFAC model and Dortmund-UNIFAC model were more useful for the recovery and water-washing processes of crude BDF and purification process of water-washed BDF, respectively.