增加聚酯装置工艺操作弹性的过程分析

详细分析计算了聚酯生产装置的第一酯化反应器热量需求 ,初步探讨了最终缩聚反应器的工艺能力 ,指出了该装置运行过程中增加操作弹性的解决方案     

半连续直接酯化法生产PET新进展

<正> 自1991年4月广东珠海富华化纤股份有限公司将原有6m~3聚酯生产装置由加压酯化法改造为半连续式直接酯化(常压操作)工艺以来,该装置不仅可生产常规PET切片,而且已连续生产了一年多膜用PET切片,取得了相当好的效果,带来了可观的经济效益,膜用切片还获得了广东省优秀新产品奖。     

酯化塔异常时的操作

介绍了聚酯装置酯化工艺的流程,对实际生产中酯化塔异常时的操作进行了综述,如开车时塔的加压酯化时,脱水塔液泛时,提降负荷情况下,在闷料情况下,脱水塔干塔时的操作。通过上述操作可使酯化塔恢复平稳,保证酯化反应的正常进行。     

最新专利

PBT装置酯化釜的清洗方法（公开号CN102211102A公开日2011．10．12申请人中国石油化工集团公司） 该发明涉及PBT装置酯化釜的清洗方法,属于化工生产技术领域。以三甘醇为清洗剂,按以下步骤实施：将酯化釜、工艺塔、清液贮槽、污液贮槽及相应管道内的物料全部排尽。酯化釜处于降温充氮状态,釜温低于150℃,将三甘醇由清液贮槽经工艺塔卸入酯化釜,其液位漫过釜内加热列管的高度,然后对酯化釜进行缓慢升温至255℃,维持在该温度下蒸煮浸泡10—15h。清洗物从酯化釜出口排向污液贮槽,在污液贮槽内部冷却至80℃之后,用泵排出装桶,最后用生产水对装置进行全面清洗。该方法可以有效清洗PBT装置酯化釜,釜内壁及列管外壁上的大多数结焦碳化物松动并被清除,产品色值、酯化釜供热效率、过滤器使用周期等情况明显好转。     

三甘醇（TEG）清洗在PBT聚合装置中的应用

基于三甘醇（TEG）清洗的工作原理,通过对PBT（聚对苯二甲酸丁二醇酯）聚合装置酯化釜进行TEG清洗操作,摸索清洗所需工艺流程改造、清洗操作参数、准备工作,对使用TEG和1,4-丁二醇（BD）为清洗济的清洗效果进行了比较。PBT酯化釜使用TEG进行热清洗后,产品质量得到了提高,清洗过程的产品降等量得到了降低,装置清洗周...     

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。     

中国化学纤维工业协会“十四五”期间重点推介的节能减排技术

正(一)聚酯装置余热充分利用集成技术聚酯装置余热充分利用集成技术充分利用了聚酯酯化工艺塔塔顶蒸汽余热,该技术将酯化蒸汽用于制备热水,然后通过热水分别加热乙二醇、浆料、长丝空调机组和制冷机。以聚酯年产27万吨为例,每年有800万大卡/h余热利用,投资回收期仅11个月,每年回收利用效益达635万元。对于酯化蒸汽的余热利用,部分企业通过传热工质与酯化蒸汽的热交换获得热量,驱动有机朗肯循环螺杆膨胀发电机发电,具有全周     

五釜工艺聚酯工业装置的稳态模拟

针对大型连续PTA直接酯化法PET工艺过程装置,以Aspen Plus和Polymers Plus为模型开发工具,建立了以反应和传质过程机理为基础的稳态模型。结果表明:该模型中包括了酯化反应、缩聚反应、二甘醇生成反应、链降解反应和乙醛生成等主副反应,且考虑了端羧基对酯化反应的自催化效应;更重要的是模型考虑了酯化阶段PTA在酯化反应器中的溶解过程和终缩聚阶段小分子的脱挥,并建立了小分子脱挥的传质系数与缩聚反应器内聚合度、黏度、温度和搅拌器转速等的关联;在此模型基础上模拟研究了第一酯化反应操作温度对各反应器出口指标的影响,指出酯化段的酯化率有一个适宜的控制范围。     

活性炭固载对甲苯磺酸催化合成尼泊金丙酯

以对羟基苯甲酸和正丙醇为原料,活性炭固载对甲苯磺酸为催化剂,回流脱水酯化直接合成对羟基苯甲酸丙酯.催化剂循环使用5次,酯化率仍可高达90.0%.该反应具有产率高、反应时间短、操作简单等优点.     

对苯二甲酸二辛酯(DOTP)生产技术

正成果简介:本技术以对苯二甲酸(PTA)或其废料、异辛醇为主要原料,在催化剂存在下,先酯化合成增塑剂DOTP,然后经过中和、水洗、脱醇、过滤等操作,最终获得成品。该技术可采用精对苯二甲酸(PTA),也可采用PTA废料为原料,同时,在相同装置也可柔性生产其他增塑剂系列,如邻苯二甲酸二辛酯邻苯二甲酸二丁酯邻苯二甲酸二     

Modeling of poly(ethylene terephthalate) reactors: 4. A continuous esterification process

A mathematical model has been developed for the direct, continuous esterification process. Influence of process and operational variables, including temperature distribution, residence time distribution, bis(hydroxyethyl)terephthalate recycle, pressure, and ethylene glycol (EG) to terephthalic acid ratio on the reactor performance have been investigated in a range as close to industrial practice as possible. The variables influencing the amount of EG reflux (which governs the energy economy) and side products (which govern the product quality) have been discussed. This investigation provides an analysis of a continuous, direct esterification process, and the results indicate strategies for optimizing productivity and product quality.     

Scale‐up und detaillierte Prozessanalyse eines Membranreaktors am Beispiel einer heterogen katalysierten Veresterung

The combination between reaction and pervaporation has been investigated using the example of a heterogeneous catalysed esterification reaction. The process model parameters have been determined based on experimental investigations and a scale‐up has been performed to the pilot scale. A detailed process analysis leads to optimal operating as well as structural variables and two separation sequences have been suggested.     

聚酯(PET)反应过程研究⒇Ⅳ酯化反应过程数学模拟

通过对酯化反应器流动模型的分析结合酯化反应化学平衡、反应动力学和反应器内传质的研究建立了适用于多种工业酯化反应器的数学模型     

渗透汽化-酯化反应耦联膜过程动力学模型

建立了渗透汽化 -酯化反应耦联复合膜反应器过程动力学模型及测量复合膜渗透率的方法 .该动力学模型较系统地考虑了复合膜反应器中可能影响酯化反应化学平衡移动的各种因素 .研究结果表明 ,模型的模拟结果能很好地与实验结果相吻合 .     

Simulation of continuous packed bed reactive distillation column for the esterification process using activity based kinetic model

A mathematical model for the continuous packed bed reactive distillation process of esterification of acetic acid with methanol is developed. The kinetic rate equation, which plays a major role for the performance of reactive distillation and it is the part of model, is required for the liquid phase reversible esterification reaction. The mineral sulphuric acid is used as the catalyst. The kinetic experiments are carried out under different temperatures in the range of 305.15 to 333.15 K and catalyst concentrations in the range of 0.1267 mole H⁺/lit to 0.6537 mole H⁺/lit. From that experimental data the kinetic model is developed and the same is used for the simulation of reactive distillation process. Equilibrium stage model, in which the vapour and the liquid leaving a stage are assumed to be in equilibrium with each other, has been used for the simulation of reactive distillation process by incorporating our kinetic model. Conversion of acetic acid as function of reflux ratio and reboiler ratio has been predicted. The liquid composition and temperature profiles versus stage number have been also predicted. Finally, the optimum operating conditions obtained from the simulation results for high pure methyl acetate by reactive distillation process.     

Analysis of reactive distillation using the esterification of acetic acid as an example

The uncatalyzed esterification of acetic acid is described in the literature as a typical example of reactive distillation. Many rigorous models were validated using this esterification as an example. Process proposals for the production of pure ethyl acetate from ethanol and acetic acid have been determined using short-cut methods with the assumption of chemical equilibrium only. In this publication, the limitations of this esterification are clarified, using a rigorous model that was developed. The reasons why reactive distillation appears to be unfavorable for this esterification are explained. It is, however, theoretically possible to obtain ethyl acetate in high purity with different variants of the process. Different process variants are examined in this work. Construction variables that are important for the design of reactive columns, such as the number of reactive separation stages and the holdup in the column, are analyzed. Furthermore, the influence of variables dependent on the component system, such as the phase equilibrium of the reactive system and the reaction kinetics on the conversion in the column, are described. It can be shown that the short-cut methods published so far for reactive distillation, which assume chemical equilibrium, are inadequate.     

聚酯（PET）反应过程研究：Ⅱ.酯化反应过程动力学研究

对乙二醇和对苯二甲酸直接酯化反应过程的主反应动力学和生成ＤＥＧ副反应的动力学进行了研究，得到了不同温度下的反应速率，进而获取了各反应的活化能和频率因子。     

Process Variables of the Esterification Reaction of 3‐Pentadecylphenol and Acryloyl Chloride Catalyzed by an Ionic Liquid

An efficient method was investigated for the synthesis of 3‐pentadecylphenyl acrylate (PDPA) via one‐pot reaction of esterification in the presence of an ionic liquid as catalyst. In order to understand the esterification reaction process, a mathematical relationship between the yield of esterification and the process variables was established by employing central composite design. The maximum yield of esterification of 3‐pentadecylphenol (PDP) and acryloyl chloride (AC) catalyzed by imidazole ionic liquid was found to be 85 %. A statistical model predicted that the highest esterification reaction yield would be > 88 % under optimized reaction conditions. The predicted values for optimum process conditions thus obtained were in agreement with the experimental values, thereby indicating the suitability of the model.     

Modelling and optimization of main independent parameters for biodiesel production over a Cu0.4Zn0.6Al2O4 catalyst using an RSM method

In this research, the modeling of Cu0.4Zn0.6Al2O4 catalysts performance and optimizing of esterification reactions were considered by the central composite design (RSM) response method. The main independent parameters of temperature, the ratio of alcohol to oil, the amount of catalyst and time duration have been considered for setting the esterification process. To access the maximum activity in the esterification process, the optimum conditions are estimated at 10.42 the molar ratio of alcohol to oil, 2.98 wt.% for the amount of catalyst at the temperature of 163.37 °C and within 4.15 hrs. Under these conditions, the conversion will be above 97.94%. These conditions have been applied to adjust the process of transesterification of waste cooking oil. The reusability of the Cu0.4Zn0.6Al2O4 nanocatalyst in the esterification reaction was investigated in this study. Employed statistical techniques and developed models can be employed as a useful tool for design, prediction, and optimization of the biodiesel production process with effective performance for various industrial applications. © 2021 Society of Chemical Industry (SCI).