三元物系液-液萃取过程的计算机辅助计算

本文从液-液两相级式接触萃取出发,在IBM-PC微机上调试出了用于三元物系液-液萃取过程的设计计算和操作计算的程序。该程序收敛速度快,精度高,可替代工业上传统的绘图求解法和繁琐的逐级计算法,而且对工业萃取的优化设计具有现实意义。

三元均相恒沸精馏多定态分析

研究三元均相恒沸精馏多定态现象,进行含有多个精馏区域的三角形相图的多定态分析.在全回流/具有无限多块塔板(∞/∞)的条件下,分析各个精馏区域存在多定态现象的可能性,得出存在多定态现象的两个条件和进料组成区域.在一个具有25块理论塔板数的填料塔精馏装置中,对丙酮-正庚烷-苯001类三元物系,进行连续精馏多定态实验研究,结果表现出一定程度的多定态现象.

基于热耦精馏的三组分混合烷烃分离工艺

采用Aspen Plus化工流程模拟软件,选用RK-Soave方程计算物性数据,以分离过程的年总费用(ATC)最低为目标函数,对侧线精馏热耦工艺、侧线提馏热耦工艺和完全热耦精馏工艺用于三组分混合烷烃的分离进行模拟。模拟结果表明,侧线精馏热耦工艺、侧线提馏热耦工艺和完全热耦精馏工艺分别需要274,293,142块塔板;侧线精馏热耦工艺比侧线提馏热耦工艺塔板少19块,但能耗增加14.98%;完全热耦精馏工艺比侧线提馏热耦工艺的能耗降低24.32%;完全热耦精馏工艺比侧线精馏热耦工艺和侧线提馏热耦工艺的ATC分别减少34.35%和23.08%;完全热耦精馏工艺的塔板数、能耗和ATC最低。

Ternary compounds and solid-state phase equilibria in Mg-rich side of Mg-Zn-Ca system at 300 ℃

The phase equilibria and compositions in Mg-rich side at 300 ℃ were investigated in Mg-Zn-Ca ternary system through the equilibrated alloy method by using scanning electron microscopy,electron probe microanalysis,X-ray diffraction and transmission electron microscopy.The results show that two ternary compounds T1 and T2 can be in equilibrium with the Mg-based solid solution in Mg-Zn-Ca system.T1 phase is a linear compound with the composition region（molar fraction） of 15% Ca,20.5%-48.9% Zn and balanced Mg at 300 ℃.Its hexagonal structure parameters decrease with increasing Zn content,i.e.a=0.992-0.945 nm,c=1.034-1.003 nm.T2 phase has hexagonal structure with the composition region of 26.4%-28.4% Mg,63.2%-65.5% Zn and 7.1%-8.4% Ca.At 300 ℃,the solubility of Zn in the Mg-based solid solution increases for the addition of Ca,the maximum solubility of Zn is 3.7%.Three-phase fields consisting of--Mg＋Mg2Ca＋T1,--Mg＋T1＋T2,--Mg＋T2＋MgZn and MgZn＋T2＋Mg2Zn3 exist in the Mg-Zn-Ca system at 300 ℃.

Effect of Potassium on Ammonium Fixation and Adsorption of Vermiculite in Binary and Ternary Systems

Ammonium fixation and adsorption experiments were conducted to study the effect of potassium on ammonium fixation into interlayer of vermiculite and ammonium adsorption at the surface of vermiculite both in the binary (NH-4～(+)-Ca～(2+)) and ternary (NH-4～(+)-K～(+)-Ca～(2+)) systems. In the ammonium fixation experiment, 5 mmol NH-4～(+) kg～(-1) was added alone, or after, before or simultaneously with 5 mmol K～(+) kg～(-1) to the vermiculite (vermiculite:solution = 1:1), and the incubation was conducted for 3 days under constant 20℃. In the adsorption experiment, after addition of 10 mmol Ca～(2+) L～(-1) as matrix ions, either NH-4～(+) alone with a concentration series from 0.1 to 5.0 mmol NH-4～(+) L～(-1) (binary exchange system of NH-4～(+) and Ca～(2+) or NH-4～(+) together with 5 mmol K～(+) L～(-1) (ternary exchange system of NH-4 ～(+), K～(+) and Ca～(2+) was added to vermiculite at a vermiculite to solution ratio of l:10 for 24-h equilibrium. The results of the fixation experiment showed that the presence of K～(+) increased NH-4～(+) fixation for all the treatments, regardless of the addition orders. For ammonium adsorption a linear relationship between activity ratios of NH-4～(+) to Ca～(2+) and Mg～(2+) in the equilibrium solutions (ARNH-4) and increases of exchangeable NH-4～(+) at the surface of vermiculite after 24- h equilibrium (△Ex-NH-4) was shown for almost the whole concentration ranges tested. Compared with the binary system, the slope of the curve of the ternary system was steeper, indicating a more intensive adsorption of NH-4～(+) in the presence of K～(+). It was demonstrated that K ～(+) did not reduce the ammounium fixation into the interlayer and ammonium adsororption at the surface of vermiculite, which indicated that, under the experimental conditions of this study, K～(+) did neither occupy the sites for NH-4～(+)-fixation in the interlayer nor the sites for NH-4～(+)-adsorption at the surface of vermiculite.

Determination of Vapor Pressures for Binary and Ternary Mixtures Containing Ionic Liquid 1-propyl-3-methylimidazolium Bromide

Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.

Activity Coefficient Models to Describe Vapor-Liquid Equilibrium in Ternary Hydro-Alcoholic Solutions

In this study,three semipredictive activity coefficient models:Wilson,non-random-two liquid model(NRTL),and universal quasi-chemical model(UNIQUAC),have been used for modeling vapor-liquid equilibrium properties of ternary mixtures that include substances found in alcoholic distillation processes of wine and musts.In particular,vapor-liquid equilibrium in ternary mixtures containing water + ethanol + congener has been modeled using parameters obtained from binary and ternary mixture data.The congeners are substances that although present in very low concentrations,of the order of part per million,are important enological parameters.The results given by these different models have been compared with literature data and conclusions about the accuracy of the models studied are drawn,recommending the best models for correlating and predicting phase equilibrium properties of this type of mixtures.

Study on Critical Properties for CO_2+Cosolvent Binary System and Ternary System

The performance of supercritical fluid (SCF) as a solvent can be greatly affected by addition of anentrainer to the system. In this study, a constant volume visual method is used to measure the critical point ofCO2+n-butyraldehyde, CO2+ i-butyraldehyde and CO2+alcohol binary systems and CO2+entrainer+trisodiumsalt of tri-(m-sulfonphenyl)phosphine (TPPTS) ternary systems, which provides us good theoretical basis for super-critical extraction and chemical reaction. The relationship between critical point and concentration of the entrainerare discussed. The phase behavior of binary system and that of ternary system are compared. The relationshipbetween the concentration of TPPTS and critical point of binary systems are also discussed.

Surface complexation modeling of Eu(Ⅲ) adsorption on silica in the presence of fulvic acid

Humic substances （HS） substantially affect heavy metal （M） adsorption on mineral surfaces. However, quantitative descriptions of ternary systems involving M, HS and mineral surfaces remain unclear. This study examines adsorption in a model ternary system including Eu（III）, fulvic acid （FA） and silica, and describes the adsorption of Eu（III） and FA by combining a double-layer model （DLM） and the Stockholm humic model （SHM）. SHM explains the binding of H＋ and Eu^3＋ to EA and the DLM for FA and Eu（Ill） adsorption on silica. Experimental results showed that the presence of FA promotes Eu（III） adsorp- tion at acidic pH values, but decreases it at basic pH values, which indicates the formation of ternary surface complexes. Modeling calculations have shown that two ternary surface complexes are required to describe the experimental results in which Eu^3＋ acts as a bridge between the surface site and FA. The present study suggests that the discrete-site approach to HS is a promising method for interpreting the adsorption data for M, HS and mineral ternary systems.