醋酸乙烯生产工艺

正公开了一种生产乙酸乙烯酯的方法。该方法包括在催化剂存在下反应乙烯、乙酸和氧,以生成包含乙酸乙烯酯、乙烯、二氧化碳、乙酸、水和乙二醇二乙酸酯的反应混合物。反应混合物被分离成含有乙烯的气体流、二氧化碳和含有乙酸乙烯酯、乙酸、水和乙二醇二乙酸酯的粗醋酸乙烯流。乙二醇二乙酸酯流从粗醋酸乙烯酯流中分离出来,经过反应蒸馏回收乙酸。     

UNIFAC法关联水和乙二醇的汽液平衡

应用ＵＮＩＦＡＣ模型对水和乙二醇系统的汽液平衡进行了关联,求得了水和乙二醇相互作用参数ａＨ２Ｏ,ＤＯＨ＝－１８,ａＤＯＨ,Ｈ２Ｏ＝－１１０。应用上述模型参数于ＵＮＩＦＡＣ模型,于不同压力下计算了水和乙二醇的汽液平衡与文献值十分相符。     

聚酯生产中的乙二醇回用试验

由聚酯生产过程中污乙二醇回用的模拟研究结果,说明了污乙二醇中所含二甘醇、齐聚物、水和醛等杂质对聚酯工艺有影响。齐聚物的存在有利于对苯二甲酸的溶解,加快了酯化反应速度,较高含水量会引起酯化反应过程中压力的波动,并会增加乙二醇脱水塔的负荷,醛在反应过程中大部分被分馏出,而残留的醛会使产品色相变差。试验给果表明:直接法生产聚酯过程中,从缩聚真空系统中排出的污乙二醇完全可以返回酯化段直接参与配料。考虑到醛含量对产品色相的影响,回用的乙二醇配比不宜超过50%。乙二醇直接回用的经济效益预计每吨聚酯切片可降低乙二醇消耗约2.5kg,对苯二甲酸约1.1kg。     

三段减压连续精馏草酸酯催化加氢制乙二醇产物的研究

采用了三段连续减压精馏的方法进行分离纯化草酸酯催化加氢产物中乙二醇,精馏后乙二醇纯度达到99.9%.产物中乙醇含量较高,因此需回收利用,通过提馏后回收的乙醇纯度达到99%.实验考查了分离工艺条件,为工业化分离设计提供基本依据.     

萃取精馏法回收制药废液中四氢呋喃和甲醇

采用装有1.5 m高θ丝网填料的玻璃精馏塔对含有四氢呋喃、甲醇和水的制药废液进行了萃取精馏分离研究。以乙二醇为萃取剂,溶剂比为1.75∶1、精馏段高度为1.0 m、回流比为1.5时,四氢呋喃回收率可达99.5%。精馏回收萃取剂乙二醇时,所需填料高度为60 cm,回流比为1.0时乙二醇回收率达99.6%。回收甲醇所需填料高度为0.7 m,回流比为3.0时甲醇回收率为99.7%,甲醇摩尔分数为0.988。研究表明,乙二醇是分离含四氢呋喃、甲醇和水的制药废液的适宜的苹取剂。     

油酸钠/十二烷基麦芽糖苷混合体系溶液的聚集行为

通过表面张力法和荧光探针法研究了阴离子表面活性剂油酸钠(NaOA)与非离子表面活性剂n-十二烷基-β-D-麦芽糖苷(DDM)组成的二元混合体系分别在水和体积分数为20%的乙二醇水溶液中的聚集行为。利用Rubingh模型和Maeda模型得到的相互作用结果一致,表明NaOA/DDM混合体系在水和20%的乙二醇水溶液中均存在协同效应,在NaOA摩尔分数达到0.4时,混合体系的协同效应均达到最强。乙二醇的加入增大了混合体系的临界胶束浓度,降低了表面活性剂的吸附效率。荧光测试结果表明,乙二醇能够破坏胶束结构,减小胶束聚集数,增加微环境极性。     

PET装置真空喷淋循环乙二醇沉降分离的数学分析

通过对循环乙二醇中乳状或絮状悬浮颗粒物的受力及运动状态的数学分析,论述了采用沉降分离提纯和净化循环乙二醇的可行性及其分离效果。     

乙二醇水溶液精制过程的模拟与优化

介绍了乙二醇的用途及供需现状;针对聚酯行业的乙二醇水溶液,运用Aspen Plus软件对乙二醇精制分离方案进行模拟计算,以降低能耗为目标,对精馏塔的理论板数、回流比以及进料位置对分离效果及能耗的影响进行了分析,获得了合理的优化设计及操作参数。     

煤制乙二醇产品塔真空度波动原因分析及处理

煤制乙二醇工艺路线中,由于原料粗乙二醇中杂质较多,乙二醇精馏分离系统普遍采用真空精馏方式.某煤制乙二醇企业生产过程中,乙二醇产品塔真空度发生不规律性波动,对其发生的原因进行分析,并提出相应的解决办法.     

浅析乙二醇和二乙二醇的分离方法

本文主要对乙二醇与二乙二醇的具体分离方法进行了分析。文中首先对乙二醇与二乙二醇的分离方法进行详细的解析,然后对乙二醇二甲醚的具体制作方法进行了阐述,最后对整体式的聚双环二烯的衍生产品加以描述。希望对我国化工产业的发展起到一定的帮助。     

Simulation of Continuous Esterification Process of Polyester Polyols

Based on the kinetic and thermodynamic equations, a comprehensive mathematical model for the continuous esterification process of polyester polyols was developed, which was carried out in an innovational bubbling reactive distillation tower (BRDT) at atmospheric pressure. In this new type of reactor, direct esterification between ethylene glycol and adipic acid was accomplished efficiently and rapidly. A bench BRDT with the height of 2 m was applied for the esterification process of poly (ethylene adipate) (PEA). In the continuous operation, linear oligomers were discharged from the bottom of the column, while water passed a few column trays and a packing section as a condensation byproduct. The influence of major operating conditions on reactor performance was also simulated. Simulation results were in good agreement with experimental data, providing a strategy for developing and optimizing this process.     

聚酯装置酯化生产过程动态模拟

动态模型是进行生产过程动态优化的基础。本文采用链段法建立了聚酯装置酯化生产过程反应器和工艺塔相互影响的动态模型,分析了基本控制系统作用下过程操作工况的动态阶跃响应特性。模拟结果表明,酯化反应器进料摩尔配比及反应器温度、压力、液位的调整显著影响了酯化过程气相流的变化,且对反应产物中端羧基含量和聚合度等指标的响应比较灵敏;控制系统对稳定酯化生产过程操作起着显著的作用。     

四产品Kaibel隔壁精馏塔分离丙二醇混合物的模拟与节能分析

研究了包含甲醇、水、丙二醇和二丙二醇四组分混合物的分离问题,针对混合物的特征和分离要求,提出四产品Kaibel隔壁精馏塔的分离工艺,并利用Aspen Plus软件对Kaibel塔进行设计与节能分析。首先,设计了分离四组分混合物的三塔精馏流程（TCD）和热集成三塔精馏流程（HTCD）;其次,开展了四产品Kaibel塔分离四组分混合物的模拟研究,取得了满足分离要求的塔设计参数;最后,采用能量衡算和㶲损失分析相结合的方法,对Kaibel塔的用能特征进行了分析和比较。研究表明,与热集成三塔精馏流程相比,四产品Kaibel塔在操作费用方面不占优势,但在设备投资方面具有明显优势,可以实现在一个塔内四组分的分离,总㶲损失可降低9.41%。     

联合精馏分离四氢呋喃-水共沸物的实验及优化模拟

由于四氢呋喃与水会生成沸点64 ℃的最低共沸物,采用三塔联合精馏的方法对其进行分离。根据文献资料选择乙二醇作为萃取精馏过程的萃取剂,并在脱水塔中对萃取精馏塔产物进行脱水。选择Aspen Plus软件对工艺流程进行模拟。选择Wilson模型及RadFrac模块对单塔工艺参数进行模拟及优化,确定了各塔进料板与回流比等最适宜参数。经实验考察的项目结果均与模拟结论一致。脱水塔产物四氢呋喃含水量可低至170 μg/g。根据优化后的参数在Aspen Plus中进行全工艺流程的闭合与模拟,终产物四氢呋喃的质量分数可达0.9995,收率为0.9988。其质量分数优于常见双塔萃取精馏流程。     

Control analysis of an extractive dividing-wall column used for ethanol dehydration

This paper deals with design and control of an extractive dividing-wall distillation column (EDWC) for ethanol dehydration using ethylene glycol as entrainer. An initial design, based on a section analogy procedure for a conventional extractive distillation sequence, was obtained and then used in an optimization process to minimize the total annual cost. It was shown that the EDWC can result in significant savings over the conventional process. As these savings sometimes go along with a decrease in the control properties, an investigation of two control structures for the EDWC and one for the conventional column configuration was performed next.It was observed in closed-loop simulations that the EDWC with an appropriate structure exhibited good control properties and that its closed-loop responses were similar to those obtained for the operation of a conventional extractive distillation system.     

考虑反应热的乙氧基化反应精馏塔能量内部集成与优化

以正丁醇和环氧乙烷为原料合成乙二醇正丁醚(EGMBE)为例,利用数学模型和模拟分析方法,研究了包含大量反应热效应的乙氧基化反应精馏(ERD)塔中反应热的利用及系统能量优化问题。研究表明,当采用常规的、将反应段直接叠加于提馏段之上的塔设计时,反应热并没有贡献于分离操作或减小再沸器的热负荷,而只是被冷凝器中的冷却介质移走。分析了反应热的可利用途径,提出一种将反应段和提馏段分割、从反应段移出反应热供提馏段加热的内部热集成乙氧基化反应精馏结构--IHIERD。模拟结果表明,IHIERD 将使再沸器的温度从462.5 K降低到420.0 K,冷凝器负荷降低11%,外部能量输入降低14%,节能效果显著。     

考虑内部热集成的乙二醇反应精馏系统设计与优化

针对环氧乙烷水合制乙二醇反应精馏过程反应热的利用和系统能量更大集成问题,提出一种将反应段和提馏段分割、从反应段移出热量供提馏段加热的内部热集成反应精馏塔（R-HIDiC）的设计。利用Aspen Plus模拟软件,分析了内部热集成的可能性,优化了内部热交换量及其分布,给出了一种不需要再沸器的能量最大集成方案。研究表明,与传统的反应精馏塔相比,通过对内部热集成进行优化,乙二醇反应精馏塔可取消再沸器,系统需要的能量只由环氧乙烷水合反应热和外部压缩机提供,其操作费用将降低约47.2%,总费用将降低约39.1%,体现了其技术和经济优越性。     

Heterogeneous extractive batch distillation of chloroform-methanol-water: Feasibility and experiments

A novel heterogeneous extractive distillation process is considered for separating the azeotropic mixture chloroform-methanol in a batch rectifying column, including for the first time an experimental validation of the process. Heterogeneous heavy entrainer water is selected inducing an unstable ternary heteroazeotrope and a saddle binary heteroazeotrope with chloroform (ternary diagram class 2.1-2b). Unlike the well-known heterogeneous azeotropic distillation process and thanks to continuous water feeding at the column top, the saddle binary heteroazeotrope chloroform-water is obtained at the column top, condensed and further split into the liquid-liquid decanter where the chloroform-rich phase is drawn as distillate. First, feasibility analysis is carried out by using a simplified differential model in the extractive section for determining the proper range of the entrainer flowrate and the reflux ratio. The operating conditions and reflux policy are validated by rigorous simulation with ProSim Batch Column^® where technical features of a bench scale distillation column have been described. Six reproducible experiments are run in the bench scale column matching the simulated operating conditions with two sequentially increasing reflux ratio values. Simulation and experiments agree well. With an average molar purity higher than 99%, more than 85% of recovery yield was obtained for chloroform and methanol.     

Robust optimization of the heteroextractive distillation column for the purification of water/acetic acid mixtures using p-xylene as entrainer

The separation of water and acetic acid mixtures is a challenging task in the terephthalic acid production process. This study addresses the techno-economical optimization of an heteroextractive distillation column that uses p-xylene as entrainer. The optimization of this column is performed by means of robust optimizers belonging to the BzzMath library, coupled with the detailed process simulation of the downstream section performed with the commercial software SimSci PRO/II. A comparison with respect to the commercial simulator optimizer and a quantification of benefits are given. Results show that the BzzMath robust optimizer reaches a lower Total Annual Cost (−3.5%) with respect to the commercial software optimization. Finally, the comparison with other entrainers proposed in literature for the advanced distillation of the water/acetic acid mixtures demonstrates the economical and operational appeal of this process configuration.     

催化精馏塔内甲酸甲酯水解制甲酸的研究

在催化精馏塔内以压制的强酸性阳离子交换树脂为催化剂填料对甲酸甲酯水解制甲酸进行了实验研究.在全回流操作条件下,通过改变操作参数获得了高于90%的水解转化率.考虑到反应过程中水的阻碍作用,根据实验结果提出了可用于催化精馏过程的动力学方程并建立了基于平衡级理论的反应与分离耦合的数学模型.通过设定进料水酯摩尔比、回流与进料比、反应段与分离段理论级数等参数获得了水解过程的仿真结果,并提出了较佳的工艺操作条件.研究表明:仿真结果与实测数据相吻合;通过改变操作条件可调整反应段内水与甲酸甲酯的浓度,提高水解速度;增加反应段的高度比增加分离段的高度更有利;产品甲醇和甲酸在催化精馏塔内能够完全分离,反应段两端反应速度高于中间段的反应速度.