热泵精馏与常规精馏的热力学分析比较

以实际运行装置的丙烯精馏塔为例,采用PROⅡ 9.4软件对丙烯—丙烷分离过程中常规精馏和热泵精馏分别进行模拟,通过分析模拟结果,对比两种精馏方式的公用工程消耗、能耗及其经济性.     

反应精馏研究进展及应用前景

对反应精馏技术在工艺和模拟方面的研究进展进行了概述 ,简单介绍了反应精馏的关键技术并对反应精馏的应用前景进行了展望。     

普通精馏和共沸精馏精制粗乙酸的研究

通过对该体系气液相行为的研究,建立了多相共沸精馏的热力学模型并计算出模型参数。应用化工模拟软件AspenPlus,以现场操作数据为基础,对脱低沸塔和脱高沸塔组成的双塔精馏过程以及单塔(粗乙酸精制塔)普通精馏过程进行模拟,计算结果同工业生产中的实测数据基本吻合。通过模拟计算,确定了理论塔板数和最佳回流比,发现在降低能耗和提高乙酸质量回收率上单塔精馏优于双塔精馏。选取乙酸异丁酯作为共沸剂进行共沸精馏模拟,并与普通精馏方法进行了对比。     

LPG精馏过程模拟开发

应用PRO/II化工模拟软件对LPG精馏过程进行模拟,在模拟分析的基础上,开发了LPG精馏工艺流程,确定了各精馏塔的工艺操作参数,如压力、温度、塔板数、进料板位置、温度灵敏板位置等。     

催化精馏技术及其模拟计算

叙述了催化精馏技术的原理及其在酯化、水解、烷基化等反应中的应用,介绍了催化精馏过程的模拟模型,重点阐述了催化精馏模拟计算的应用,并对模拟软件在催化精馏模拟计算中的应用进行了阐述,应用Aspen Plus、ChemCAD等软件能较好地模拟催化精馏过程。     

萃取精馏在甲醇精馏中的应用

为了提高甲醇产品质量,研究了萃取精馏在甲醇精馏中的应用。结合实际工程经验,应用ASPEN模拟软件,分析在甲醇精馏中应用萃取精馏的实例。结合萃取精馏的基本原理,分析特征组分在精馏塔内的相对挥发度。萃取精馏已经成功应用于多个甲醇项目,产品均同时达到O-M-232K AA级和GB 338-2004标准,说明萃取精馏在粗甲醇精馏中的应用是成功的。     

反应精馏技术研究进展

反应精馏作为一种新型特殊精馏,因其独特的优势而在化学工业中日益受到重视.本文简要介绍了其基本原理、特点以及分类,重点阐述了国内外反应精馏的模拟和应用研究进展,展望了反应精馏技术的发展方向.     

年产20万吨甲醇精馏Aspen模拟计算

该设计是针对20万吨的甲醇精馏工段的设计与模拟,通过对比二塔精馏、三塔精馏、四塔精馏的流程,取各种流程的优缺点对传统四塔精馏工段进行设计优化,主要详细的进行了四塔精馏工段的预精馏工段,加压塔工段,常压塔工段,回收塔工段的设计。对甲醇生产的精馏工段用Aspen plus软件对该流程进行模拟计算。     

新型丙烯酸精馏系统的研究

针对丙烯酸传统共沸精馏系统，通过热力学数据分析，利用水、醋酸和丙烯酸本身的沸点差异，提出了采用直接精馏方式提纯丙烯酸的工艺技术方案。基于Aspen Plus流程模拟软件，对丙烯酸共沸精馏工艺及直接精馏工艺进行了流程模拟与分析，发现采用直接精馏工艺可有效简化丙烯酸精制工艺，并降低丙烯酸精馏单元的能耗，对未来丙烯酸装置的设计及运行具有重要指导意义。     

甲醇单效精馏与双效精馏的能耗分析与对比

结合唐山中润煤化工有限公司的实际工况,以流程模拟软件为基本分析工具,将单效精馏系统与双效精馏系统的能耗进行了计算与对比,计算数据表明,就系统的蒸汽消耗量和冷却水使用量,双效精馏系统比单效精馏系统低一半以上。并对实际工况下双效精馏系统的能量传递进行了分析,解释了实际工况下常压塔顶呈现负压的原因。     

ADSORPTIVE DISTILLATION

A traditional countercurrent approach to the fluid movement in a cascade or fixed-bed stages undergoing cyclic liquid phase adsorption-vapor phase desorption is used to uncover a simple-to-use design technique for the prediction of number of stages to effect a prescribed separation. Analogous to the McCabe-Thiele method, the derivation shows the q-parameter depends on reflux ratio, feed ratio and solids loading ratio. For uniform solids loading, the q-line always takes a slope of infinity. Stage-to-stage calculations proceed sequentially using simple graphical methods by defining a pseudo-equilibrium curve. For the usual case of non-linear liquid phase equilibria, it is shown that the pseudo-equilibrium curve depends on selectivity and the respective hold-ups associated with adsorption on the one hand, and drained solids on the other. The theoretical results are entirely amendable to straightforward digital computation for design.

An example calculation is given for the very difficult to separate binary isomer system ortho in meta xylene. Based on published data, graphical computations for separation of a 50/50 mixture of the isomers into products of 95% purity show that only seventeen stages are necessary using a reflux ratio twice the minimum.     

EXTRACTIVE DISTILLATION PERFORMANCE

The effectiveness of Koch-Sulzer BX structured packing and random protruded packing are compared for an extractive distillation operation which exhibits high liquid to vapor ratios. The extractive distillation operation studied separated an 88/12 wt% toluene/heptane mixture with N-methyl pyrrolidone (NMP) as the solvent in a 0.15 m diameter column with about 5.5 m of packing. The effect of pressure drop and HETP on gas capacity factor, liquid loading and liquid-to-vapor ratio are examined.     

恒沸精馏模拟计算

本文开发了塔顶产物为非均相恒沸物的恒沸精馏定态模拟算法。将恒沸精馏塔分为包括再沸器的塔体、冷凝器和液体分层器三部分,对三部分依次串联迭代计算。经五个实例模拟计算表明,只要操作条件指定合理,本算法只需要用很简单的初值,能以较快的速度收敛到正确解,同时所需计算机内存较小。     

DISTILLATION UNDER ELECTRIC FIELDS

ABSTRACT

Distillation is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE of some binary mixtures is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum.

     

催化精馏技术的应用

综述了国内外催化精馏发展状况，介绍了催化精馏在芳烃烷基化，加氢，酯化和水解反应，甲缩醛的合成，三废处理等化工过程中的工艺流程及其与传统工艺相比所具有的优势，并进一步阐明催化精馏现存在的问题和解决思路。     

分批精馏模拟技术

综述了当前分批精馏模拟技术的研究进展。介绍了作为目前快捷（ｓｈｏｒｔｃｕｔ） 模型主流的ＦＵＧ快捷模型和ＩＳＣ 快捷模型。与严格模型相比,ＦＵＧ模型和ＩＳＣ 模型具有适应性强、计算量小、计算精度较高的独特优点。     

甲醇精馏方案技术对比

对粗甲醇的双塔精馏和三塔精馏工艺进行技术方案、投资、消耗、能耗、成本等方面的对比,对采用空冷器时的技术方案进行初步研究,研究结果界定两种工艺方案的适用装置规模。     

EXTRACTIVE DISTILLATION BY SALT EFFECT

Extractive distillation employing a dissolved salt instead of a liquid third component as the separating agent is a promising but relatively neglected technique for achieving azeotropic and other difficult separations. In systems for which a soluble and effective salt can be found, major savings in both capital and energy costs are possible. The technical aspects of such processing are described using examples from our own work and that of others. The pioneering work by Donald F. Othmer in this field is outlined.