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.     

合成硝基麝香三元体系的固液平衡

通过试验测定了合成硝基麝香二元体系的固液平衡数据,回归并修正了UNIFAC模型的相互作用参数,使UNIFAC模型具有更高的预测功能;为了评价修正后的UNIFAC模型对合成硝基麝香三元体系的预测功能,利用试验测定的溶解度数据和修正后的UNIFAC模型计算值进行了比较,结果表明相互作用参数的修正是理想的.     

合成硝基麝香在溶剂中固液平衡研究

采用综合法测定了合成硝基麝香在乙腈等溶剂中的固液平衡数据,采用UNIFAC方程对麝香在单一溶剂中的固液平衡数据进行了关联,结果表明UNIFAC方程能够较好地关联实验数据并具有一定的预测功能,为麝香混合物的溶液结晶分离提供了理论依据。     

含麝香体系多元溶液固液平衡研究

测定了酮麝香、二甲苯麝香在单一溶剂和混合溶剂中的溶解度以及酮麝香的中间体 2 ,6 二甲基 4 叔丁基苯乙酮在不同溶剂中的溶解度 ,并且测定了多溶质多溶剂体系的固液平衡 ,采用UNIFAC活度系数法进行以上体系的固液平衡计算 ,计算结果与实验测定结果吻合良好。采用文中提出的方法不仅可以预测多溶质体系在溶液中共同达到饱和时的溶解度 ,而且可以预测部分溶质达到饱和时的溶解度 ,这对于溶液结晶具有重要的指导意义     

气液色谱测UNIFAC参数

UNIFAC参数通常是由二元系汽液平衡数据回归得到,现有的数据几乎都已被用到了。鉴于汽液平衡实验繁冗而不经济,1979年Zarkarian等开始用气相色谱测定r~∞回归,他们用了两种方法:两个或多个r~∞(相应的基团分别在溶质和溶剂中存在)结台或r~∞与Flory-Huggins方程相结合。但由这两种方法回归得出的UNIFAC参数用于预测汽液平衡并不理想。1982年,Alessi等对UNIFAC方程作了修正,仍以多r~∞回归,推算了若干体系的汽液平衡。但这些作者对于用气液色谱测UNIFAC参数有无局限性,尤     

UNIFAC模型关联碳酸酯合成体系的汽液平衡

利用UNIFAC模型对甲醇氧化羰基合成碳酸二甲酯(DMC)体系中的各组分及DMC与苯酚酯交换合成碳酸二苯酯(DPC)体系中的各组分进行了基团划分.根据实验测定的甲醇-DMC、甲醇-草酸二甲酯(DMO)、DMC-DMO、甲醇-苯酚、DMC-苯酚五组二元物系等温汽液平衡数据,拟合了新基团-OCOO-和其他基团间的UNIFAC相互作用参数,扩充了UNIFAC模型的应用范围.与原基团划分的UNIFAC模型关联结果比较,采用新基团划分法推算得到的汽液平衡数据的计算值与实验值偏差较小,说明新基团划分更合理.     

一个新的基团贡献型状态方程——GC-MCSPT方程

将超额Gibbs函数模型与修正的硬球三参数状态方程(MCSPT方程)相结合,导出由基团贡献模型定义的状态方程参数混合规则.直接利用低温下的基团贡献模型参数,如UNIFAC模型、修正的UNIFAC模型(简称MUNIFAC)的交互作用参数,分别预测了二元强极性物系的低压和高压相平衡以及三元强极性物系的汽液相平衡.结果表明,新模型具有广泛的预测能力和满意的预测精度.     

萃取精馏分离四氢呋喃-乙醇共沸物系

首先根据汽液平衡实验数据采用UNIFAC法进行VLE关联。然后通过定性判断、基团贡献法定量估算选择该二元物系的合适萃取剂为乙二醇。通过气液平衡实验对萃取剂的有效性进行验证．比较了不同溶剂比对四氢呋喃,乙醇相对挥发度的影响,当溶剂比为3时,相对挥发度为2．26。最后进行精馏实验验证过程的可行性。     

正丙醇/水+乙腈汽液相平衡的测定、关联及预测

为了对乙腈基共溶剂进行萃取精馏分离就必须先准确获得相应的二元汽液相平衡数据。设计适合于此类物系分离的萃取精馏就必须获得准确的二元汽液相平衡数据。文章在常压下用改进的Othmer釜测定了正丙醇+乙腈和水+乙腈2个物系的二元汽液平衡数据,分别用面积和点对点法对实验数据进行了热力学一致性检验,并用Margules,Van Laar,Wilson,NRTL,UNIQUAC方程对实验数据进行了关联。最后使用基于基团贡献法的UNIFAC和基于量子力学和统计热力学的COSMO-RS和COSMO-SAC对2种物系的相平衡进行了预测,所得结果即可应用于精馏过程的设计,也可作为Aspen Plus,PROⅡ等软件的输入参数。     

合成麝香双液相萃取结晶溶剂研究

对组分处于低共熔点的麝香体系提出了一种新的萃取方法———双液相萃取结晶。利用修正的UNIFAC模型对麝香在不同溶剂中的平衡数据进行预测,根据相平衡数据对各种溶剂进行比较,从理论上筛选出麝香体系合适的萃取溶剂,再进行实验验证。结果表明,麝香混合物在加入2种溶剂(乙腈+环己烷)完全溶解后,出现明显的分相,在不同的相中麝香的比例均比初始比例发生了很大的变化,得到了理想的富集,这样就使每种麝香更容易分离。     

酮麝香、二甲苯麝香和1,3-二甲基-2,4-二硝基-5-叔丁基苯固-液相平衡研究

The solid-liquid equilibria of musk ketone musk xylene, musk xylene 1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are measured by differential scanning calorimeter (DSC), these systems are proved to be simple eutectics. Moreover the melting points and the fusion enthalpies of musk ketone, musk xylene and 1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are also measured by the DSC. These solid-liquid equilibrium data and the heats of fusion are reported for the first time. Then UNIFAC model is used to correlate the solid-liquid equilibrium data.It is shown that the solid-liquid equilibria of musk systems can be predicted bv the UNIFAC model.     

计算机辅助筛选分离联苯与4-联苯乙酮两种化合物的溶剂

引言 4-联苯乙酮是合成非甾体抗炎药联苯乙酸和液晶材料的重要精细化工中间体[1].以联苯为原料,在无水三氯化铝存在下,用乙酰氯或醋酐进行傅一克反应可合成4-联苯乙酮[2-3];反应结束后加入碎冰和盐酸水解,然后静置分层,分出油层,水层用二氯乙烷多次萃取;萃取物并入油层,减压蒸去溶剂后可得到4-联苯乙酮粗品;文献[4]以氯仿为萃取剂从水层中提取目的产物.     

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.     

Liquid-liquid and vapour-liquid behaviour of oleyl alcohol applied to extractive fermentation processing

Investigations into the product recovery step of the extractive ethanol fermentation through partition experiments for ethanol-water-Adol^r? 85 NF ternary systems were undertaken. Experimental liquid-liquid equilibrium data for this ternary system were compared with numerical predictions based on the UNIFAC method. The influence of salts on distribution coefficients for ethanol extraction was also examined. An improvement in extraction characteristics was observed for ternary systems with salts. Flash vaporisation was used to subsequently examine the effect of liquid-liquid ternary compositions on vapour-liquid partitioning. The UNIFAC model was found to be very useful for semi-quantitative analysis of such liquid extraction systems.     

UNIFAC模型在粗蒽分离中的应用

根据相平衡原理，并结合ＵＮＩＦＡＣ模型，建立了固液平衡条件下求取溶质在溶剂中溶解度的方法。该模型用于蒽、菲溶解度的推算，计算结果与实验值吻合较好。     

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.     

有加合物生成体系固液平衡预测

在Stoicos和Eckert工作的基础上,用实测的加合常数,结合正规溶液化学模型、UNIFACA化学模型、理想化学模型对有加合物生成体系的固液平衡预测作了研究.测定了四氯化碳/对二甲苯、四氯化碳/偏三甲苯、苯胺/苯酚、苯胺/间甲酚、苯胺/邻甲酚及苯胺/邻氯酚6个体系的加合常数,并据此计算了这些体系的固液平衡,与文献相图比较,结果令人满意.     

苯或甲苯萃取己内酰胺和甲基己内酰胺分配系数的测定和预测

To get high purity caprolactam is a challenging task in the chemical fiber industry. To date, reports on the prediction of the distribution of caprolactam and its derivative chemicals have been few. In this study, the ex-traction of caprolactam with toluene as the extractant and N-methyl caprolactam with benzene and toluene as the extractants has been carried out. By defining new UNIFAC groups and calibrating related interaction parameters, a UNIFAC method was introduced to predict the equilibrium concentration of caprolactam and methyl caprolactam in toluene or benzene extraction processes. The calculated results fit very well with the experimental data. Using the UNIFAC model, the selectivity of extractants can be predicted.