乙苯在315催化剂上催化脱氢制苯乙烯的动力学研究

用近于理想流的恒温管式反应器,对乙苯在315催化剂上催化脱氢制苯乙烯的反应过程进行了动力学研究。确立了乙苯脱氢的经验性幂式速率方程以及基于Langmuir-Hinshelwood 机理导出的双曲线型速率方程。根据动力学数据与模型解析,给出了乙苯脱氢主、副反应网络及其相应的所有动力学参数。     

环柱状催化剂内强放热复合反应──传质──传热耦合过程研究(Ⅱ)本征反应动力学及反应──传质──传热耦合过程数学模型

用等温积分反应器,在与工业生产相似的条件下,研究了银催化剂上乙烯氧化制环氧乙烷本征反应动力学,得到了能反映该系统反应特性的速率方程．建立了乙烯氧化制环氧乙烷环柱状银催化剂内复合反应-传质-传热耦合过程二维数学模型。     

环柱状催化剂内强放热复合反应──传质──传热耦合过程研究(Ⅱ)本征反应动力学及反应──传质──传热耦合过程数学模型

用等温积分反应器,在与工业生产相似的条件下,研究了银催化剂上乙烯氧化制环氧乙烷本征反应动力学,得到了能反映该系统反应特性的速率方程．建立了乙烯氧化制环氧乙烷环柱状银催化剂内复合反应-传质-传热耦合过程二维数学模型。     

甲醇合成反应器催化剂使用周期与样品分析数据的关联性分析

在不同的操作条件下,甲醇合成反应器铜基催化剂的使用寿命有很大变化,催化剂自身的状况对分析数据也有很大的影响。本文对甲醇合成反应器催化剂的使用周期进行了统计,找到了催化剂工况与分析数据之间的关系。随着催化剂的性能下降,主反应的进行程度较浅,造成甲醇合成反应器循环气中的CO含量逐渐增大,同时催化剂性能的下降导致副反应增多,有机酸含量增大,造成粗甲醇的p H下降。     

甲缩醛与三聚甲醛合成聚甲氧基二甲醚反应速率研究

为了探究反应条件对聚甲氧基二甲醚合成的影响,采用对甲基苯磺酸改性的强酸性阳离子交换树脂为催化剂,在固定床反应器中考察了甲缩醛和三聚甲醛合成聚甲氧基二甲醚的催化活性并研究了反应速率方程。结果表明,该催化剂具有较好的催化活性,三聚甲醛的转化率达到95%以上。根据连串反应机理,建立了幂函数反应速率方程,采用四阶龙格库塔方法对反应速率方程进行计算,使用粒子群算法(Particle Swarm Optimization)对反应速率方程参数进行了拟合回归。结果表明,该反应速率方程能较好地反映甲缩醛和三聚甲醛的转化率以及产物分布,为反应器模拟以及放大生产提供了基础数据。     

甲醇反应器的CFD模拟与换热优化

混合气制备甲醇是目前较为常用的工业生产甲醇方法，利用CFD软件模拟甲醇的固定床反应器，在Fluent中输入主副反应的动力学，得到模拟结果并针对该强放热反应提出设备换热上的优化方案，在提高甲醇产量的同时，保证反应器内部有较高的正向反应速率。     

乙酸甲酯非均相水解动力学的研究

在搅拌釜式间歇反应器中研究了在G－26H型阳离子交换树脂催化下的乙酸甲酯非均相水解反应动力学。实验测定了搅拌速度、催化剂粒径、反应温度、催化剂用量对反应速率的影响,检验了催化剂的重复使用性,获得了乙酸甲酯水解的反应速率方程。     

腐蚀金属对甲醇羰化合成醋酸反应的影响

结合工业生产催化体系中存在的腐蚀金属,研究了其对羰基合成醋酸反应的影响.在高压反应釜中,通过添加不同浓度的醋酸亚铁或醋酸镍考察腐蚀金属铁和镍对铑基催化剂和铱基催化剂反应活性和选择性的影响,并利用平行反应器在模拟闪蒸条件下考察腐蚀金属对主催化剂稳定性的影响.结果表明,少量腐蚀金属铁或镍的存在对铑催化羰基合成醋酸的反应活性...     

合成气制乙二醇反应器大型化措施

针对国内在运乙二醇装置受列管式羰化反应器及列管式加氢反应器限制难以大型化,造成装置建设投资高、能耗高、副反应产物多、生产负荷低、蒸汽消耗大等缺陷,南京敦先化工科技有限公司开发出径向蛇管式羰化反应器和径向球腔联箱蛇管式加氢反应器,解决了乙二醇装置大型化的难题,不仅投资省,而且催化剂床层阻力低,同时气体流经羰化反应器催化剂床层内进外出和流经加氢反应器催化剂床层外进内出等设计理念从羰化反应及加氢反应的源头控制副反应产物的生成,提高了草酸二甲酯(DMO)的收率,降低了原料气和精馏蒸汽等的消耗,可有效降低装置的运行费用,为企业带来可观的经济效益。     

三聚甲醛工业生产的研究进展

三聚甲醛是一种重要的化工中间体,且三聚甲醛能解聚生成甲醛,特别是当需要无水甲醛作反应剂时,它的应用更有价值。近年来,利用三聚甲醛合成聚氧亚甲基二甲醚作为清洁燃油组分也得到了广泛的重视。本文着重分析了三聚甲醛的合成方法、反应器的选择、催化剂、停留时间等对副反应、转化率的影响,并概述了目前工业生产中三聚甲醛的精馏工艺进展。     

环氧乙烷合成反应器数学模拟

针对扬子石化公司乙烯氧化制环氧乙烷工业规模的壁冷式固定床反应器,在YS-6型银催化剂宏观动力学模型的基础上加以修正,获得了YS-7型银催化剂宏观动力学模型,建立了环氧乙烷合成固定床反应器的一维拟均相模型.通过模型计算值与工业生产实际值的比较,发现两者相差很小,从而验证了反应器模型和所用的宏观动力学模型的准确性,可用作扬子石化公司环氧乙烷合成反应器的模拟与操作优化.     

乙烯氧化反应器数学模拟

针对扬子石化公司乙烯氧化制环氧乙烷工业规模的壁冷式固定床反应器,在YS-6型银催化剂宏观动力学模型的基础上加以修正,获得了YS-7型银催化剂宏观动力学模型,建立了环氧乙烷合成固定床反应器的一维拟均相模型,通过模型计算值与工业生产实际值的比较,两者相差很小,验证了反应器模型和所用的宏观动力学模型的准确性,可用作扬子石化公司环氧乙烷合成反应器的模拟与操作优化。     

环氧乙烷合成反应器温度-时间优化策略

根据工业实际生产数据反算得到能够反映催化剂失活特性的银催化剂失活动力学方程.在失活模型基础上,对环氧乙烷合成反应器的管外沸腾水温度-时间策略进行优化,得到最优沸腾水升温曲线,从而提高环氧乙烷反应的经济效益.对同系列新型催化剂的反应器操作优化提出了可行的研究方法.     

环氧乙烷非均相催化水合动力学及均温反应器热稳定性分析

采用碳纳米管增强复合材料催化剂,在等温积分反应器中获得环氧乙烷非均相催化水合宏观反应动力学实验数据,建立了幂函数型宏观反应动力学方程,采用Levenberg-Marquardt法对动力学模型参数进行估算,并以该动力学模型为基础,分析了均温反应器的热稳定性。结果表明,生成乙二醇主反应的表观活化能为71.7 k J/mol,与两个典型的串联副反应的活化能接近。模型参数统计检验结果表明,该宏观动力学方程参数是适定的,可用于工业反应器的设计。给出的反应器关键参数的计算方法,可为乙二醇合成反应器的模拟计算和设计开发提供必要的依据。     

Dynamic mathematical modeling of a novel dual-type industrial ethylene oxide (EO) reactor

In this paper, the dynamic behavior of a novel dual-type industrial ethylene oxide reactor has been proposed with taking catalyst deactivation into account. The configuration of two catalyst beds instead of one single catalyst bed is developed for conversion of ethylene to ethylene oxide. In the first reactor which is an industrial fixed-bed water-cooled reactor, the feed gas is partly converted to ethylene oxide. This reactor functions at very high yield and at a higher than normal operating temperature. In the second converter, the reaction heat is used to preheat the feed gas to the first reactor and a milder temperature profile is observed. The potential possibilities of a two-stage catalyst bed system are analyzed using a 1D heterogeneous dynamic model to obtain necessary comparative estimates. A differential evolution (DE) algorithm is applied as an effective and robust method to optimize the reactors length ratio. The results obtained from the simulation demonstrate that there is a desirable catalyst temperature profile along the dual-type reactor (DR) compared with the conventional single-type reactor (SR). In this way, the catalysts are exposed to less extreme temperatures and thus, diminishing the catalyst deactivation via sintering. Results from this study provided beneficial information about the effects of reactors configuration on catalyst lifetime and ethylene oxide production rate simultaneously.     

钛硅分子筛催化环已酮氨肟化反应动力学

An intrinsic kinetics of cyclohexanone ammoximation in the liquid phase over titanium silicate molecular sieves is investigated in an isothermal slurry reactor at different initial reactant concentrations, catalyst loading,and reaction temperature. The rate equations are developed by analyzing data of kinetic measurements. More than 10 side reactions were found. H202 decomposition reaction Inust be considered and other side reactions can be neglected in the kinetic modeling. The predicted values of reaction rates based on the kinetic models are almost consistent with experimental ones. The models have guidance to the selection of reactor types and they are useful to the design and operation of reactor used.     

Steady-state and transient behavior of a continuous polyethylene terephthalate condensation polymerization process. I. Melt transesterification stage

The steady-state and transient behavior of a continuous stirred-tank reactor for melt transesterification of dimethyl terephthalate with ethylene glycol in the presence of metal acetate catalyst is presented. The kinetic model includes the main transesterification reactions and side reactions leading to diethylene glycol and carboxylic acid end groups. The effect of various reactro operating parameters such as [EG]/[DMT] mole ratio and feed catalyst concentration on the product distribution under steady-state reactor operating conditions is analyzed. The dynamic process model has also been solved and the reactor transients to step changes in various reactor parameters are reported.     

Polyethoxylation and polypropoxylation reactions: Kinetics,mass transfer and industrial reactor design

Ethoxylation and propoxylation reactions are performed in the industry to produce mainly non-ionic surfactants and ethylene oxide(EO)–propylene oxide(PO) copolymers.Both the reactions occur in gas–liquid reactors by feeding gaseous EO,PO or both into the reactor containing a solution of an alkaline catalyst(KOH or Na OH).Non-ionic surfactants are produced by using liquid starters like fatty alcohols,fatty acids or alkyl-phenols,while when the scope is to prepare EO–PO copolymers the starter can be a mono-or multi-functional alcohol of low molecular weight.Both reactions are strongly exothermic,and EO and PO,in some conditions,can give place to runaway and also to explosive side reactions.Therefore,the choice of a suitable reactor is a key factor for operating in safe conditions.A correct reactor design requires:(i) the knowledge of the kinetic laws governing the rates of the occurring reactions;(ii) the role of mass and heat transfer in affecting the reaction rate;(iii) the solubility of EO and PO in the reacting mixture with the non-ideality of the reacting solutions considered;(iv) the density of the reacting mixture.All these aspects have been studied by our research group for different starters of industrial interest,and the data collected by using semibatch well stirred laboratory reactors have been employed for the simulation of industrial reactors,in particular Gas–Liquid Spray Tower Loop Reactors.     

三相鼓泡淤浆床环氧乙烷合成反应器数学模拟及工程分析

建立了加压三相鼓泡淤浆床环氧乙烷合成反应器的数学模型 ,计入了催化剂颗粒在床层中沉降形成沿床高浓度分布对反应的影响以及由于惰性液相载体部分返混对传递的影响 ,进一步利用经实验验证的上述数学模型模拟不同表观气速、床高、反应器直径 (扣除传热元件截面积 )、进口乙烯摩尔分数等参数对床层中催化剂浓度随床高的分布、出口环氧乙烷摩尔分数、环氧乙烷选择率以及单位质量催化剂环氧乙烷年产量的影响 .通过模拟分析预示了工业三相床环氧乙烷反应器的合理尺寸、表观气速、环氧乙烷选择率以及时空产率 ,为工业化提供必要的设计依据     

Vapor phase reactions of acetaldehyde over type X zeolites

Vapor phase reactions of acetaldehyde over X zeolites were studied at 1 atm and 300–400°C using a fixed-bed, integral-flow reactor. The catalytic activities decreased in the order: KX > NaX > HX, in accordance with the trend of catalyst basic strength. The product selectivities of 3-hydroxybutanal, butanal and benzene increased with increasing catalyst basic strength, whereas the reverse trend was found for those of ethylene oxide, propane and dihydrofurans. The reaction network and associated mechanisms are proposed and discussed. The main pathway was self-condensation of acetaldehyde to 3-hydroxybutanal, followed by dehydration to 2-butenal. Other side reactions include isomerization, reduction, cyclodehydration and sequential cross-condensation–cyclodehydration. The kinetic parameters for acetaldehyde reactions over NaX zeolite were estimated.