【作者】 史奇冰；

【导师】 王子镐；

【作者基本信息】 北京化工大学 ， 化学工程， 2004， 硕士

【摘要】 混合物系新分离方法的研究对于工业过程开发与改造具有重要的意义。对于难分离体系如共沸体系、结构性质相近体系新型分离方法的研究一直是分离技术的研究热点之一。近年来,随着对吸附分离认识的加深,新型吸附剂的开发,萃取精馏、膜技术以及离子液体的出现,基于不同技术组合的集成分离方法不断出现,为分离工程的发展和技术进步带来了新的机遇。本论文主要包括如下三部分:固液吸附平衡的热力学模型研究;离子液体对单一体系和混合体系汽液平衡影响的理论研究;有关离子液体汽液平衡的实验研究。固液吸附现象在化学工业中具有重要的应用,例如液体混合物的吸附分离,污水的吸附处理以及固液非均相催化反应的选择性等过程均与固液吸附平衡有关。本论文根据热力学一致性的吸附质-固体溶液理论,采用 Wilson 方程描述吸附质之间以及吸附质与吸附剂之间的相互作用,建立了一个计算吸附平衡的热力学模型。并用该模型关联了 1-辛烯/ 正辛烷、1-癸烯/ 正己烷、1-己烯/ 正己烷、苯/ 正庚烷、苯/ 环己烷等二元系在固体吸附剂上的吸附平衡,同时预测了1-己烯/ 正己烷体系在不同温度下的吸附平衡,关联与预测误差均在 5%以内,表明该模型具有良好的关联和预测能力,可望用于实际 I<WP=4>北京化工大学硕士学位论文体系固液平衡的计算。离子液体由于其本身的特性,作为环境友好溶剂在反应和分离过程中具有良好的应用前景,含离子液体体系的汽液平衡计算以及模型化研究对于离子液体在分离过程的应用具有重要的理论和实际意义。本文采用非电解质溶液的 NRTL 方程来表示溶液的非理想性,关联并预测了水-丁基甲基咪唑六氟化磷和水-辛基甲基咪唑六氟化磷体系的等温汽液平衡,计算误差在 2%以下。该模型还用于关联十几个有机溶剂-离子液体体系在不同温度下有机物无限稀释活度系数的实验数据,得到了有关的 NRTL 二元作用参数,在此基础上预测了离子液体对苯-环己烷、己烷-乙醇、环己烷-乙醇、甲醇-环己烷和甲醇-正己烷等几个二元共沸体系汽液平衡的影响。结果表明,含离子液体体系的汽液平衡可以采用传统的非电解质模型来描述,离子液体的“盐效应”可以显著改善组分的相对挥发度甚至消除共沸现象,这对开发离子液体在加盐萃取精馏方面的工业应用具有重要的指导意义。建立了液体蒸汽压的测量装置,并测定了水-乙基甲基咪唑溴、水-丙基甲基咪唑溴体系的汽液平衡数据。结果显示,离子液体能降低水的饱和蒸气压。尽管该装置的精度还不是很高,但为进一步开展离子液体体系的热力学研究做了前期准备工作。更多还原

【Abstract】 Study of novel separation method for mixed system is of greatsignificance for the development and renovation of industrial processes.Searching for new separation method for such systems as azeotropicsystem and the system with similar structure and property, and thereforehard to be separated has long been a hotpot of separation technology.Owing to the better understanding on adsorption process and thedevelopment of new absorbent, the appearance of extractive distillation,membrane technology and ionic liquid, some integrated separationtechnologies have been appeared on the basis of combination of differenttechnologies available, which provide a new opportunity for thedevelopment and the technological advancement of separationengineering. This paper includes three sections: thermodynamic modeldevelopment for solid-liquid adsorption equilibrium; study on the effectof ionic liquid on the vapor-liquid-equilibrium (VLE) for single andmixed systems; VLE measurement for ionic liquid containing systems. III<WP=6>北京化工大学硕士学位论文 Solid-liquid adsorption is of great significance in Chemical Industry.Typical applications include adsorptive separation of a liquid mixture,treatment of wastewater and selectivity adjustment of heterogeneous solidcatalytic reaction etc. Based on the adsorbate-solid solution theory, athermodynamically consistent model was developed for the calculation ofadsorption equilibrium by describing interactions among adsorbates andadsorbent components with Wilson equation. This model was used forcorrelating adsorption isotherms for several binary systems such as1-octene/ n-octane、1-decene/ n-hexane、1-hexene/ n-hexane、benzene/n-heptane and benzene/ Cyclohexane, also the adsorption isotherm of1—hexene/n—hexane at other temperatures was predicted by this model,both correlation and prediction deviation were within 5%. This suggeststhat the present model has a good performance in correlating andpredicting binary adsorption isotherms, and is expected to be applicableto the calculation of solid-liquid equilibrium of practical system. Ionic liquid as a benign solvent is of great potential to be applied inchemical reaction and separation processes due to its unique attributes.And the modeling and calculation of VLE for the ionic-liquid containingsystem is of both theoretical and practical importance. By using NRTLequation for non-electrolyte solution, the VLE isotherm ofwater-[bmim][PF6] and water-[pmim][Br] was correlated and the VLEdata at other temperatures were predicted, the calculation deviation was IV<WP=7>北京化工大学硕士学位论文within 2%. The experimental infinite activity coefficients of some organicchemicals in ionic liquids at varying temperatures were correlatedsuccessfully with NRTL equiation, and the binary parameters thusobtained were used to study the effect of ionic liquid on the VLE ofazeotropic binary systems such as benzene-cyclohexane 、Hexane-Ethanol 、 cyclohexane-Ethanol 、 methanol-cyclohexane andmethanol-hexane. It is shown that VLE for ionic containing systems canbe well represented with conventional NRTL equation, the relativevolatility of component can be largely affected and azeotropic point caneven be eliminated by the “salt effect” of ionic liquid. This is importantin guiding the application development of ionic liquid in the extractivedistillation. The equipment for the measurement of saturated vapor pressure wasestablished, and the VLE data of water-[emim][Br] and water-[pmim][Br]binary systems were obtained. It is shown that ionic liquid can reduce thesaturated vapor pressure of water. Although this equipment is not veryaccurate, it provides a preparative work for the further study ofthermodynamic properties of ionic liquid systems.更多还原