半间歇搅拌釜式乙氧基化反应器的数学模拟

以KOH催化条件下乙二醇乙氧基化为例,建立了工业规模的、同时考虑动力学、气液平衡、气液传质、反应体积变化和惰性气体氮气影响等的半间歇搅拌釜式乙氧基化反应器的数学模型。通过数学模拟考察了环氧乙烷进料速率对反应器操作的影响,得到安全限制下适宜的环氧乙烷进料速率。在此基础上,模拟得到反应器中压力、环氧乙烷在气液相中的组成及乙氧基化产物随时间的分布,并同工业试验数据进行了比较。结果表明了模型的可靠性。     

乙氧基化反应器的模型化及其研究进展

介绍了乙氧基化原理及工业反应器的特征,综述了乙氧基化反应器的模型化方法,包括动力学、气液平衡、质量传递模型及参数获取方法。介绍了工业半间歇乙氧基化反应器的模拟方法及取得的一些进展,并对该领域的研究提出展望。     

乙氧基化管式反应器的数学模拟

建立了乙氧基化管式反应器的数学模型,考察了各参数对反应器温度分布的影响,认为反应器具有较强的参数敏感性,冷却剂进口温度是影响反应器温度分布的主导因素。分析了反应器的参数敏感性,得到了反应器的安全操作区域,对放大和生产操作提供了理论指导。     

气升式内环流反应器流场及传质特性数值模拟

采用双流体模型和气液二相流体动力学理论建立了气升式环流反应器流体流动的数学模型,在此模型的基础上利用溶质渗透理论和各向同性湍流理论建立了局部液相体积传质系数数学模型。采用计算流体软件F luent对气升式环流反应器内气液二相流动状况进行模拟,模拟结果较好地解释了气升式环流反应器内的流动行为及传质特性。模拟计算值与文献实验值的吻合说明了模型的可行性。     

TPA和EG连续生产PET的第一酯化反应器操作模拟

对乙二醇(EG)和对苯二甲酸(TPA)连续生产对苯二甲酸乙二酯(PET)的第一酯化反应器进行了数学模拟。数学模型中包括了反应动力学方程、气液平衡和气液传质方程,使模拟结果接近于工厂实践。此外对不同停留时间、不同的反应器操作温度及压力、不同的进料 EG/TPA 的 mol比,进行了模拟计算,得出了反应器出口各种产物的组成随操作参数的变化,并对各操作参数的范围和对反应的影响进行了评述。     

硅油光-热老化气升式反应器数值模拟

为进行液浸聚光光伏系统中液浸液体即二甲基硅油在光热条件下的老化实验研究,设计制作了气升式外环流光催化反应器。采用Fluent软件欧拉多相流模型和RNG k-ε湍流模型对反应器进行了三维全尺寸数值模拟。分析了结构参数、操作参数和硅油物性参数对反应器中气液两相流动的影响,得到反应器内循环液速和气含率等参数的分布。模拟结果与实验结果有较好的一致性。模拟结果表明:硅油黏度越小,循环液速越大,气含率越小;反应器适宜操作气速不应大于0.02 m/s;反应器最适宜高径比和环隙面积比分别为47.6和0.31~0.41。     

TPA和EC连续生产PET的第一酯化反应器操作模拟

对乙二醇（ＥＧ）和对苯二甲酸（ＴＰＡ）连续生产对苯二甲酸乙二酯（ＰＥＴ）的第一酯化反应器进行了数学模拟。数学模型中包括了反应动力学方程、气液平衡和气液传质方程，使模拟结果接近于工厂实践。此外对不同停留时间、不同的反应器操作温度及压力、不同的进料ＥＧ／ＴＰＡ的ｍｏｌ比，进行了模拟计算，得出了反应器出口各种产物的组成随操作在数的变化，并对各操作参数的范围和对反应的影响进行了评述。     

气泡循环流动型膜生物反应器流体力学特性研究

以气升式环流反应器和膜生物反应器为基础,提出气泡循环流动型膜生物反应器的概念.利用气液循环流动减缓膜污染,通过充压渗透的操作方式,降低水处理能耗与设备投资.实验研究了下降管内中空纤维膜填充率对反应器的平均气含率、循环液速等流体力学性能的影响,使用模拟体系考察膜分离性能. 研究结果表明:循环流动的气液两相能够明显缓解膜污染,提高膜渗透通量;利用充压渗透的操作方式可以实现膜分离过程,同时加压操作会导致平均气含率减小,循环液速降低.在理论分析基础上,导出平均气含率、循环液速随操作气速和压强的变化关系.     

搅拌反应器内气液两相流的CFD研究进展

搅拌式气液反应器因其操作灵活、适用性强等优点,在过程工业中应用广泛.综述了采用计算流体力学CFD技术对搅拌反应器内气液两相流动行为的数值模拟研究.Euler-Euler双流体模型作为主要方法用于描述气液两相流动,在其基础上耦合相对简单的气泡数密度函数模型或复杂的群体平衡模型,可较为准确地预测搅拌反应器内气泡尺寸和局部气含率及其分布规律.CFD模拟结果可用以分析和评价不同搅拌桨叶、搅拌桨组合和气体分布器的气液分散性能,对气液反应器的结构优化和过程强化提供了有效手段.     

钴膦催化剂丙烯低压醛化制丁醇数学模型的研究

本文报导丙烯低压醛化制丁醇气液并流填料鼓泡反应器的数学模型的研究.在实验室模型级装置上验证了该数学模型的结果,表明带有接触效率系数的本征动力学方程式可以作为丙烯低压醛化制丁醇的反应器数学模型,为放大设计提供参考.     

A mathematical model for unsteady-state oxygen transfer in an external-loop airlift reactor

A mathematical model for simulation of unsteady-state oxygen transfer in an external-loop airlift reactor was developed. The airlift reactor was represented by a number of interconnected tanks, each of which was assumed to be well mixed. The effect of gas circulation rate on the oxygen transfer was considered. The model can be used for the determination of mass transfer performance of the airlift reactor in which the whole liquid phase cannot be assumed to be fully backmixed. The simulation results showed a good agreement with experimental results.     

Modeling of an industrial fixed bed reactor based on lumped kinetic models for hydrogenation of pyrolysis gasoline

In this work, a mathematical model of an industrial fixed bed reactor for the catalytic hydrogenation of pyrolysis gasoline produced from olefin production plant is developed based on a lumped kinetic model. A pseudo-homogeneous system for liquid and solid phases and three pseudo-components: diolefins, olefins, and parraffins, are taken into account in the development of the reactor model. Temperature profile and product distribution from real plant data on a gasoline hydrogenation reactor are used to estimate reaction kinetic parameters. The developed model is validated by comparing the results of simulation with those collected from the plant data. From simulation results, it is found that the prediction of significant state variables agrees well with the actual plant data for a wide range of operating conditions; the developed model adequately represents the fixed-bed reactor.     

一个反应-三相恒沸精馏系统的模拟研究——(Ⅰ)醋酸-乙醇-水-醋酸乙酯四元体系的热力学模型和计算

本文提供醋酸—乙醇—水—醋酸乙酯四元体系的热力学模型和计算方法,为带反应器的恒沸精馏计算所需的相平衡和热量平衡计算提供方法和依据.该四元体系的液相具有强极性,在一定温度下分层;气相存在醋酸分子缔合.除醋酸外的其它三组分间存在三元或二元共沸物.计算模型考虑到这些特点.ASOG模型用于计算活度系数,并与UNIFAC模型作了比较.用经验方法处理醋酸分子在气相中的缔合.热力学性质的计算结果与实验数据(共150组)在合理的误差范围内吻台.本文的模型和方法用于带反应器的精馏塔计算时可拟合实际生产数据.     

热力学状态方程二元交互作用参数估算模型开发

基于气液平衡理论,建立了热力学状态方程二元交互作用参数估算模型。首先,结合气液平衡理论、状态方程以及相应的混合规则建立气液相平衡数学模型;然后以气相组成误差平方和与压力相对误差平方和之和作为目标函数,并使用计算机编程,利用单纯形法进行优化求解,实现了热力学状态方程二元交互作用参数估算模型的开发;最后,用该模型对5组二元气液平衡体系中的组分二元交互作用参数进行估算,并根据估算出的参数对各体系的气相组成进行预测,结果显示,预测值与实验值的平均相对偏差均小于1％,表明该模型计算结果准确,可应用于气液平衡计算中。     

Numerical simulation of fixed-bed catalytic reactor for isopropyl alcohol synthesis

The mathematical model and the method of its numerical analysis for fixed-bed catalytic reactors were developed and were applied to the pilot reactor of isopropyl alcohol (IPA). The experimental results from pilot test runs were used to test and verify the simulation results. The numerical simulation gives the IPA concentration and temperature profiles in the reactor. The production of IPA from a commercialized ethanol rector was examined. The operation conditions of IPA synthesis were established.     

液固环流反应器流动状况的数值模拟

利用计算流体力学方法对液固环流反应器内的液固流动行为进行了数值模拟. 由Euler法的双流体模型和颗粒动力学理论建立了数学模型，对液固环流反应器内液固两相流动状况进行模拟，模拟结果很好地解释了液固环流反应器内的流动行为，固体颗粒速度模拟计算值与实验值的吻合说明了模型的可信性.     

Modelling of a fluidized bed bioreactor for immobilized enzymes (Part 2)

In the first part of this contribution, a mathematical model was presented for a liquid fluidized bed using immobilized enzymes, with reversible Michaelis-Menten kinetics. This part is focused on the experimental results. The reaction kinetics of native and immobilized enzymes was determined in continuous stirred tank reactors under comparable conditions. The influence of external mass transfer was investigated in a fixed bed reactor column. The extend of pore diffusional resistance was examined in a continuous stirred tank reactor and with a numerical simulation. Hydrodynamics was measured in different reactor columns (diameter d_t = 0.052 ? 0.225 m; length L: 1.0–2.0m) and with a static mixer. Further, the concentration profile was determined in a fluidized bed reactor with side stream analysis for different biocatalyst samples, fluid velocities and bed heights. The simulation of experimental results indicates that they are well described by the developed model. Furthermore, the model is well suited to predicting the influence of specific parameters on the effective kinetics of the biocatalyst and the expansion of the fluidized bed.     

尼龙66连续缩聚过程模拟

为加深对聚己二酰己二胺(尼龙66)缩聚过程的理解,指导尼龙66生产过程的优化和新工艺开发,本研究基于聚合反应特性以及反应器流体力学特征,耦合聚合反应动力学模型、水-聚合物体系的汽液平衡模型以及传质模型,建立了尼龙66连续缩聚过程管式反应器和后缩聚反应器的数学模型,实现了尼龙66连续聚合过程的模拟。聚合物分子量及水含量的模拟值符合工业生产数据,验证了模型的可靠性,模拟分析了聚合工艺参数对聚合物分子量及水含量的影响,结果表明减少醋酸含量、提高反应器温度、降低管式反应器和后缩聚反应器压力均有利于快速提升聚合物分子量。较优的工艺条件为后缩聚器温度280~285℃,卧管式反应器压力1.600~1.750MPa。建立的模型准确性好,可用于考察工艺参数的影响,指导工业应用。     

DME DIRECT SYNTHESIS FROM SYNGAS IN A LARGE-SCALE THREE-PHASE SLURRY BUBBLE COLUMN REACTOR: TRANSIENT MODELING

In this research, a new transient mathematical model based upon tanks-in-series configuration was developed to simulate the direct synthesis of dimethyl ether (DME) from syngas in a commercial-scale slurry bubble column reactor. A comparison between the simulation results and experimental data showed that the applied model might acceptably describe the behavior of the slurry reactor. Furthermore, simulation results in the heterogeneous bubble flow regime indicated that the proposed model with 10 tanks-in-series provided the optimum condition. Utilizing this transient model and considering catalyst deactivation, the effect of operating conditions on DME productivity and CO conversion were investigated. In addition, the dynamic behavior of the reactor was studied after implementing a step change in the reactor's coolant fluid temperature.