酮麝香、二甲苯麝香和双溶剂四元体系液液相平衡研究

本文计算并测定了酮麝香、二甲苯麝香、二甲基亚砜(或乙腈)和庚烷(或环己烷)四元体系的液液相平衡,试验结果与计算值基本吻合。平衡双液相中两种麝香的比例不同于原料,两液相中两种麝香分别得到了富集,其中二甲基亚砜(或乙腈)相中富含酮麝香、庚烷(或环己烷)相中富含二甲苯麝香,这种液相分相可用于分离麝香混合物。本文的研究为麝香混合物的分离提供了理论指导。此外,采用本文的方法还可以预测较难测定的多元固、液混合物的相平衡关系。     

合成硝基麝香混合物固-固相平衡研究

从分子间相互作用的角度进行研究,计算得到酮麝香、二甲苯麝香体系的相互作用能量参数λ,代入NRTL方程,结果表明酮麝香、二甲苯麝香混合物为简单低共熔体系,差分扫描量热证实了作者的理论研究结果。     

酮麝香与二甲苯麝香体系相平衡研究

为了判断酮麝香、二甲苯麝香固相存在状态,改进Lennard-Jonnes位能函数后得到了适用于极性和非极性分子的位能函数式,计算得到酮麝香、二甲苯麝香体系相互作用能量参数λ,结合NRTL方程计算确认酮麝香、二甲苯麝香为简单低共熔体系,采用差分扫描量热热分析法进行了实验验证。     

熔融结晶法分离提纯对二甲苯

针对混合二甲苯吸附分离后得到的对二甲苯中含有少量甲苯物系,提出熔融结晶法分离对二甲苯与甲苯的新工艺。采用差示扫描量热法(DSC)测量了对二甲苯与甲苯之间的固液平衡相图,实验数据表明该二元物系为低共熔型物系,在此基础上进行液膜结晶实验,可分离得到对二甲苯纯度为99.5%以上的产品,证明采用熔融结晶法分离对二甲苯与甲苯是可行的。根据实验过程建立了液膜结晶动态过程的数学模型,由模型计算得到的结果与实验数据很好的吻合,验证了模型的准确性,并用模型优化操作条件,得到适当的喷淋密度与降温速率可改善晶层生长不均的结论。分别对熔融结晶和精馏分离过程进行成本核算,结果表明结晶过程固定投资相比精馏低很多,且操作工况稳定,易于得到高纯产品,但能耗略高,因此结晶适用于小批量生产,精馏适用于大批量生产。     

基于剩余曲线分析和变压精馏分离氯仿-乙腈-乙醇三元体系

利用剩余曲线初步分析氯仿、乙腈和乙醇三元混合物的分离过程。在分离过程中,选择氯仿作为初步分离的共沸剂,根据剩余曲线分析计算得到额外加入氯仿与原料液的最佳质量比为0.64,在此条件下混合物的初步分离过程中,塔顶产物为氯仿-乙醇共沸物,塔底产物为乙腈。再利用变压精馏分离氯仿和乙醇共沸物,高压塔和低压塔压强分别为600 kPa和101.325 k Pa。最后利用Aspen Plus对工艺进行模拟和优化,得到最佳操作条件。结果表明,氯仿、乙腈和乙醇的质量含量均大于99%,符合设计要求。     

萃取结晶法分离合成甜菜碱中氯化钠

介绍了一种合成甜菜碱过程中分离副产物氯化钠的新方法-萃取结晶法,即以甲醇作萃取剂,使甜菜碱溶液中的氯化钠结晶析出,提高甜菜碱的纯度.相图分析和试验结果表明:加入萃取剂之前对溶液进行简单蒸馏处理后,溶液组成越接近双饱和点组成[m(甜菜碱)∶(氯化钠)∶m(水)=3∶1∶1],氯化钠的结晶量就越大;并且,萃取结晶时甲醇溶剂用量占物系的75.3%时,氯化钠的结晶量最大.     

2,6-DIPN与2,7-DIPN二元体系固液相图的测定和关联

绘制了2,6-二异丙基萘(2,6-DIPN)与2,7-二异丙基萘(2,7-DIPN)二元体系的固液相图,测定了2,6-DIPN和2,7-DIPN二元混合物体系的低共熔点,并用理想溶液模型进行了关联。结果表明,2,6-DIPN与2,7-DIPN二元体系固液平衡相图为简单低共熔混合物相图,低共熔点温度为-19.5℃,组成为2,7-DIPN12.2%(质量分数,下同),2,6-DIPN87.8%,由试验数据拟合得到2,6-DIPN的熔化焓为4.878kJ/mol。     

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。     

二溴苯三元物系固液平衡测定与正规溶液模型

采用差示扫描量热法,通过对一系列"拟二元"物系固液平衡数据的测定,得到了邻二溴苯、间二溴苯和对二溴苯三元物系的固液平衡数据.实验结果表明本物系为简单低共熔型,其低共熔摩尔分数组成和温度分别为:邻二溴苯(x1) 间二溴苯(x2) 对二溴苯(x3),x1=0.4259,x2=0.5345,x3=0.0396,Tcu=238.5 K.文中绘制出了其相应的低共熔三元固液平衡相图,并采用正规溶液模型,利用二元溶液的三个相互作用参数对实验数据进行了关联,温度均方根偏差仅为1.32 K,说明正规溶液模型适用于上述弱极性异构体三元物系固液平衡的计算.     

钠锌硅系统光学玻璃的低温熔制技术

研究了低温熔制钠锌硅系统玻璃的组成和加热工艺参数,结果表明:玻璃的组成应与三元相图中三相低温共熔点的组成相对应,加入少量外加剂可以显著提高玻璃的熔制速度;玻璃熔制温度为1370～1380℃;对熔制过程中出现的一些问题,提出了相应的解决方法。     

酮麝香，二甲苯麝香溶液结晶研究

1 INTRODUCTION Musk ketone and musk xylene are important syn- thetic nitro-musks. They are high boiling substances and subject to decomposition under the condition of heat and light. When they are melted, the liquid mix- ture is very sticky, which lead to high resistance to heat and mass transfer and difficulty in solidification. As a result, it is reasonable to employ solution crys- tallization to separate and purify musk mixture. As the basis of solution crystallization, the solubility …     

酮麝香-二甲苯麝香双液相萃取结晶

To evaluate the effect of two liquid phase on the separation of musks mixture, the phase equilibria of musk ketone musk xylene dimethyl sulfoxide heptane system were studied for the first time. The whole and every part of the phase equilibrium for the quaternary system were shown by three-dimensional phase diagrams, the liquid-liquid equilibria, solid-liquid equilibria and solid-liquid-liquid equilibria of the quaternary system were also shown. As a result, the compositions of musks in the equilibrium liquid phases were different from those in the feed, that is, musk ketone was enriched in dimethyl sulfoxide phase while musk xylene was enriched in heptane phase. So these equilibrium liquid phases were useful in separating musk ketone and musk xylene. On the basis of these results, a new process “two liquid phase extractive crystallization” was proposed to separate the eutectics of musk ketone and musk xylene.     

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.     

Separation of fullerenes C60 and C70 using a crystallization‐based process

A crystallization‐based process that separates pure fullerenes C₆₀ and C₇₀ from their mixture using o‐xylene as the solvent has been developed. Isothermal solid–liquid equilibrium phase diagrams of the C₆₀‐C₇₀‐o‐xylene ternary system for a number of temperatures were first determined at 1 atm. Taking advantage of the shift in solvent‐free composition of the C₆₀‐C₇₀ double saturation point with temperature and based on the solid solution‐forming phase behavior between C₆₀ and C₇₀, the flowsheet of a general crystallization process was then synthesized. It involved the fractionation of a C₆₀‐C₇₀ fullerene mixture into C₆₀‐rich and C₇₀‐rich solid solutions using temperature‐swing crystallization, followed by purification of the solid solutions with multistage crystallization into pure C₆₀ and C₇₀ solids. To demonstrate process feasibility, bench‐scale batch experiments were performed using a commercially available fullerene mixture that was pretreated by adsorption to remove higher fullerenes. C₆₀ and C₇₀ solids of purity higher than 99 wt % were obtained. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

273 K及323 K条件下NaCl–NaBr–CH3OH三元体系相平衡 研究及其应用

为了对苦卤结晶析出的Na(Cl,Br)固溶体中氯化钠组分和溴化钠组分进行分离,测定了NaCl–NaBr–CH3OH三元体系在273及323 K温度时的溶解度数据,根据测得的液相点和湿渣相点确定了对应的固相点,由此绘制出了两个温度下的相图。结果显示,273及323 K温度下该三元体系的相图特征相似,均只有一个共饱点、两条饱和溶解度曲线,对应的固相结晶区有三个：NaCl纯盐结晶区、NaCl和Na(Cl,Br)固溶体共结晶区、Na(Cl,Br)固溶体结晶区。NaBr在无水甲醇中溶解度的增大导致NaCl溶解度大幅减小,说明NaBr对NaCl产生了较强的盐析效应,273 K时两种溶质在甲醇中的溶解度均比323 K时的溶解度大。依据273和323 K的NaCl–NaBr–CH3OH体系相图及298 K的NaCl–NaBr–H2O体系相图设计了分离Na(Cl,Br)固溶体中氯化钠和溴化钠的工艺。     

Optimization of solvent crystallization process in obtaining high purity anthracene and carbazole from crude anthracene

Solvent crystallization is the main method used for preparing anthracene and carbazole from the crude anthracene. The key to the optimization of this method is improving the solubility selectivity of the solvent by means of solvent modulating and process optimization. In this study, the solubility of anthracene, phenanthrene, and carbazole in xylene, dimethylformamide (DMF), DMF with amine/amide, isopropanolamine, and chlorobenzene is examined and the solid‐liquid ternary anthracene–carbazole–DMF/(DMF+19.96% isopropanolamine) system phase diagram is determined and applied in the solvent crystallization process. The results showed that the solubility selectivity of xylene increases with increased temperature. Also, selectivity increases with an increase of the amount of isopropanolamine in the mixture of DMF and isopropanolamine, while decreases with increased temperature. Through multiple washings of crude anthracene with xylene, DMF+19.96% isopropanolamine, and chlorobenzene, it was possible to obtain anthracene and carbazole of purity higher than 98 wt %. © 2013 American Institute of Chemical Engineers AIChE J, 60: 275–281, 2014     

用拟二元方法研究iPP-DBP-DOP三元体系的热致相分离热力学

采用拟二元方法研究等规聚丙烯（iPP）‐邻苯二甲酸二丁酯（DBP）‐邻苯二甲酸二辛酯（DOP）三元聚合物溶液的热致相分离热力学,得出了拟二元相图的数学关联方法.采用光学显微镜法测定浊点温度, 采用差式扫描量热法（DSC）测定熔点、动态结晶温度.利用浊点测定数据回归聚合物-共溶剂的交互作用参数 χ的表达式,χ是共溶剂配比和温度的函数,以此为基础计算的拟二元相图与实验数据吻合较好.发现共溶剂中DBP份数增加,相分离类型由单纯固液分相形式转变为液液分相、固液分相依次发生形式,共溶剂配比能调控拟二元相图结构.研究表明,只需测定一个较低冷却速率下几种共溶剂配比的拟二元溶液的浊点温度、分别测定几个冷却速率下iPP–DOP二元溶液的动态结晶温度即可掌握该三元溶液热致相分离热力学的全部信息.其可用来指导制膜过程,并能准确预测形成的膜结构形貌.     

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     

由铬酸钾制备铬酸钠结晶分离过程研究

以铬酸钾中间体为原料,系统地研究了采用结晶分离等常规手段制备铬酸钠产品的清洁制备方法。应用等温法分别测定了KNO3在Na2CrO4水溶液中和Na2CrO4在KNO3水溶液中的相平衡数据,绘制了溶解度曲线,确定采用先冷却结晶后蒸发结晶的方法制备铬酸钠晶体产品。考察了冷却结晶终点温度和物料配比,分析了分步蒸发结晶产品,确定了结晶最佳操作条件:K2CrO4与NaNO3的质量比在1∶(0.9～1.2),冷却结晶的终点温度控制在4℃。提出铬酸钾通过结晶方式转化为铬酸钠的整体工艺流程,并进行了全流程循环实验。采用重结晶法对铬酸钠产品进行精制,获得高纯度的铬酸钠晶体,质量分数由81.4%提高到92.2%,且粒径较大,粒度均匀。