UNIFAC基团贡献法预测合成硝基麝香固液平衡

UNIFAC基团贡献法是目前流行的一种重要的推算相平衡的方法.应用UNIFAC基团贡献法研究了合成硝基麝香物系在乙酸乙酯、乙睛、环已烷等溶剂中的溶解度.通过麝香物系在多种溶剂中的二元相平衡的实验数据对UNIFAC交互作用参数进行了回归修正,并利用这些交互作用参数预测了大量麝香的二元、三元的固液平衡.与实验值比较,证明参数修正的结果是理想的,误差在允许的范围之内,能满足合成硝基麝香体系固液平衡计算的需要.     

UNIFAC基团贡献法对合成硝基麝香固液平衡的研究

应用UNIFAC基团贡献法研究了合成硝基麝香物系在乙酸乙酯、乙腈、环己烷等溶剂中的溶解度。通过麝香物系在多种溶剂中的二元相平衡的实验数据对UNIFAC交互作用参数进行了回归修正,并利用这些交互作用参数预测了大量麝香的二元、三元的固液平衡,与实验值比较,证明参数修正的结果是理想的,误差在允许范围之内,能满足合成硝基麝香体系固液平衡计算的需要。     

基于无限稀释活度系数模型的状态方程

发展了一种从纯物质的性质参数预测混合物汽液平衡的方法,它是以立方状态方程的过量吉布斯自由能 g~E结合型混合规则和无限稀释活度系数 MOSCED模型为基础,由MOSCED模型预测得到活度系数方程的相互作用参数,从而得到混合规则中的g~E,使得状态方程能在较大温度和压力范围内预测汽液平衡.用此法预测了含极性组分体系常压到较高压力的汽液平衡,结果良好,与UNIFAC基团贡献状态方程的结果相当.     

煤炭直接液化体系高温高压气液相平衡研究进展及模型选择

笔者从气液相平衡基础理论展开并综述了高温高压相平衡计算研究进展，介绍了状态方程法、混合模型法、超额Gibbs自由能-状态方程模型法，并重点介绍了超额Gibbs自由能-状态方程模型法的思路及应用特点。针对煤炭直接液化物系高温、高压、强不对称、强极性、完全非理想体系等特点，与结合传统混合规则的状态方程法及混合模型法相比较，采用超额Gibbs自由能-状态方程模型法能够在更大范围内准确计算和预测煤液化气液相平衡。     

UNIFAC及修正模型的研究与应用进展

综述了基团贡献法UNIFAC模型的修正和应用进展。将UNIFAC模型按照适用于中小分子、聚合物及其他具体体系进行划分,介绍和讨论了各模型在相平衡计算及其他方面的应用,总结了各模型的优缺点和适用性,并指出了UNIFAC模型的发展方向。     

PSRK-UNIFAC模型在预测煤直接液化高温高压气液相平衡中的应用

为预测煤炭直接液化高温高压气液平衡,将过量吉布斯自由能混合规则和UNIFAC活度系数模型与SRK状态相结合,建立基团状态PSRK-UNIFAC模型。利用该模型对煤液化高温分离器的24种组分气液相平衡进行了预测和关联,计算值和文献值能取得较好一致,并推算了煤液化反应器内气液相组成。结果表明:PSRK-UNIFAC模型可以成功预测高温、高压、强不对称、强极性下的气液相平衡。     

UNIFAC模型的应用和发展

本文就参数增订,应用范围扩大和模型修正三方面简略评述了UNIFAC模型的应用和发展,最后论及将该模型与状态方程相结合推广应用于高压流体相平衡所做的尝试     

UNIFAC基团贡献法研究及应用进展

UNIFAC 基团贡献法是推箅组分活度系数应用最广泛的模型之一.介绍了UNIFAC基团贡献法的研究进展,分析了UNIFAC模型在气液平衡(气体溶解度、纯组分的蒸汽压、典型气液平衡预测)、液液平衡(液体混合物的表面张力、萃取精馏体系、聚合物溶液粘度的推算、典型液液平衡预测)、固液平衡(同分异构体的平衡体系、固体溶解度的计算)体系的应用领域及其局限性,并针对UNIFAC基团贡献法存在的问题,提出UNIFAC基团贡献法的研究方向和具体的研究内容.     

基团贡献法预测活度(逸度)系数(Ⅰ)

在气-液、液-液和固-液平衡计算中,用基团贡献法预测未知体系中各组分的活度(逸度)系数是行之有效的方法。本讲座系统介绍预测活志(逸度)系数的各种基团贡献法及其最新发展。共分以下五个部分:一、绪论;二、ASOG法;三、UNIFAC法;四、基团贡献分子模型;五、基团贡献状态方程。     

C_5第2萃取精馏单元过程模拟与优化

介绍了C5第2萃取精馏单元,采用Dortmund修正的UNIFAC基团贡献法预测二甲基甲酰胺-C5体系气液相平衡,修正了Wilson热力学方程中二元交互作用参数,为二甲基甲酰胺萃取精馏分离C5烃类模拟提供了适用的热力学模型。利用Aspen Plus软件,对第2萃取精馏塔进行了模拟分析,考察了萃取精馏塔主要工艺参数溶剂比(质量比)、回流比、进料位置对分离效果和塔热负荷的影响,确定了适宜的工艺操作条件,为节能降耗提供依据。     

UNIFAC模型与PRSV方程相结合预测二元及三元系统汽液相平衡

采用Ｗｏｎｇ和Ｓａｎｄｌｅｒ混合规则，将ＰＲＳＶ立方型状态方程与ＵＮＩＦＡＣ活度系数模型相结合，给出一种预测混合物相平衡热力学性质的方法，并用５４个二元体系和９个三元体系的实验数据做了检验，结果表明，该法可以较好地预测二元及三元体系的汽液相平衡。     

A group-contribution,continuous-thermodynamics framework for calculation of vapor-liquid equilibria

Continuous thermodynamics is extended to the calculation of vapor-liquid equilibria with UNIFAC. For many mixtures of discrete compounds, the UNIFAC model is an efficient method for calculating vapor-liquid equilibria of systems when experimental data are scarce or non-existent. Such constraints are especially important in continuous mixtures. The continuous distribution is characterized by model compounds chosen to reproduce the TBP analysis. The UNIFAC model is extended to systems including several gases, and the new parameters for several light gases are given. The new algorithm is described in detail. Sample calculations are shown for several semi-continuous systems.     

应用PSRK状态方程预测高压汽液平衡

为预测高压汽液平衡,将过量吉布斯自由能混合规则和UNIFAC活度系数模型与SRK状态方程相结合,建立基团贡献状态方程PSRK。利用该状态方程对5个体系在不同压力和温度下的汽液平衡数据进行了关联实验测定的汽相压力和汽相组成与计算结果相比所得的相对平均偏差分别为2．16％和1．01％。结果表明,PSRK状态方程可以成功地预测高压下汽液平衡,其精度高于MHV1和MHV2模型。     

UNIFAC模型法计算含己内酰胺体系的相平衡(英文)

An extended liquid-liquid equilibrium (LLE) UNIFAC model is proposed to describe phase equilibria of mixtures containing caprolactam. In this model, caprolactam is introduced as a new group. New group interaction parameters are calibrated from 156 sets of liquid-liquid equilibrium data. The present model gives satisfactory correlation and prediction in liquid-liquid equilibrium, including quaternary systems containing the mixed solvent of an alcohol and an alkane. The model can be applied to predict caprolactam solubility in water and benzene accurately. Freezing point and vapor-liquid equilibrium of binary systems containing caprolactam are also predicted with the extended LLE UNIFAC model. Satisfactory prediction results are obtained.     

基于UNIFAC模型的基团-OCOO-与-CH3,ACH,CH3OH和CH3COO-的交互作用参数估算与验证

Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC) ethylene carbonate and methanol ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group —OCOO— with the group —CH3, ACH, CH3OH and CHACO0— in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAG parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMG and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.     

Solid-Liquid Equilibria of Several Binary and Ternary Systems Containing Maleic Anhydride

Solid-liquid equilibria (SLE) of three binary systems and seven ternary systems containing maleic an-hydride(MA) are measured by visual method. The experimental data are compared with the calculated ones with modified universal quasichemical functional group activity coefficient(UNIFAC) method in which the interaction parameters between groups come from two sources, dortmund data bank(DDB), if there's any, and correlations based on our former presented experimental SLE data of twenty binary systems. New groups of MA, ACCOO group, COO group, >C=O group and cy-CH2 group are defined and the SLE data of rnaleic anhydride in isopropyl acetate in literature are cited in order to assess the new interaction parameters, correlated with Wilson equation and the λh equation. The modified UNIFAC method with these new regressed interaction parameters is also used to predict other three binary systems containing rnaleic anhydride.     

大豆油与甲醇酯交换反应体系的相平衡研究

生物柴油是一类清洁的可再生液体燃料,精炼植物油与甲醇酯交换是制备生物柴油的重要反应。针对目前难以准确获得酯交换反应体系的多组分相平衡组成等方面存在的问题,研究了间歇反应和连续逆流分离甘油等不同反应方式下大豆油与甲醇酯交换反应体系的多组分相平衡行为,并以三油酸甘油酯与甲醇酯交换为模型反应,采用UNIFAC和Modified UNIFAC模型进行了模拟计算。结果表明,在常压、60^oC反应条件下,在总组成偏离甲醇-甲酯二元组成的区域,UNIFAC和Modified UNIFAC模型准确计算了生物柴油酯交换反应体系的三元和四元相平衡组成。在甘油含量大于2.2%(质量)或转化率小于90%(质量)的酯交换反应中,计算值与实验值的平均偏差约为2%。酯交换反应相平衡的实验值和模型计算值表明,采用连续逆流方式分离甘油可以提高酯相中的甲醇含量,有利于传质和酯交换反应。这些结果为生物柴油工艺过程模拟、设备优化以及新技术开发提供了理论参考。     

Comparison of two predictive gE models for vapour—liquid equilibrium calculations

Ash (S.N. Ash, P. Ray and B.V. Detta, AIChE J., 31 (1985) 821; S.N. Ash, Chem. Eng. J., 48 (1992) 183) has proposed a correlation for calculating the binary parameters of the Wilson g^E model by using only pure-component parameters: solubility parameters, molar liquid volumes, relative van der Waals volumes and surfaces, critical properties, acentric factors and dipole moments. To evaluate the Ash correlation the vapour—liquid equilibria for 75 binary systems, activity coefficients at ininite dilution and excess enthalpies were predicted and compared with experimental data and with the modified UNIFAC model (J. Gmehling, J. Li and M. Schiller, Ind. Eng. Chem. Res., 32 (1993) 178). It was found that the correlation of Ash and coworkers is significantly inferior to the modified UNIFAC model and cannot be recommended for phase equilibrium predictions for those cases where UNIFAC parameters are available.     

Study of the High‐Pressure Vapour‐Liquid Equilibria for Strongly Non‐ideal Binary and Ternary Mixtures

High‐pressure vapour‐liquid equilibria for binary and ternary high polar and asymmetric systems are calculated using the Peng‐Robinson‐Stryjek‐Vera equation of state coupled with the Twu‐Coon (TWMR), the Orbey‐Sandler (OSMR) and the Wong‐Sandler (WSMR) mixing rules. Modified UNIFAC model is used for determining the activity coefficient and excess Gibbs free energy. The calculated results are compared with the experimental data and good agreement is observed. The average absolute deviation percents (AAD%)s indicated that the WSMR has less AAD% than other mixing rules in most of cases.