B112催化剂上一氧化碳变换反应工业过程动务学研究

采用“沿程积分拟合法”，在某小合成氨厂变换工段引出的支线上，利用绝热固定床反应器，对B112催化剂上一氧化碳变换反应进行了常压及加压工业过程的动力学研究。通过对不同操作条件下的床层轴向温度分布进行积分拟合，得到了适用于工业条件的过程动力学方程。一氧化碳变换反应CO＋H2O＝CO2＋H2是石油化工和煤化工重要的化学反应。国内外学者以地许多种铁系催化剂上的该反应进行了动力学研究^[1-5]，推荐了各自的本征或宏观动力学方程。本文采用“沿程积分拟合法”^[6]对国产B112催化剂上的一氧化碳变换反应进行工业过程动力学研究。按照该法的要求，实验中需采用与工业实际反应器（绝热固定床反应器）型式相同的小型反应器，在工业条件下，测定不同进口条件的反应器轴向温度分布及出口浓度，通过积分拟合获得工业过程动力学方程。     

不同形状催化剂的F—T合成宏观动力学

采用绝热固定床积分反应器，在工业条件下，对条形及片形Ｆｅ－Ｃｕ－Ｋ工业催化剂进行了Ｆ－Ｔ合成反应性及宏观动力学考查。在稳态下，用集总的方法，保持一定的轴向温度分布，求出不同形状催化剂的宏观动力学方程，与实验数据符合较好。     

C301铜基催化剂甲醇合成反应动力学(Ⅱ)宏观动力学模型

本文以工业应用为目的,采用内循环无梯度反应器,在工业甲醇合成操作条件下研究了工业粒度C301型铜基催化剂上一氧化碳、二氧化碳与氢合成甲醇的宏观动力学.选择以下二个反应:CO+2H_2(?)CH_3OH CO_2+3H_2(?)CH_3OH+H_2O为系统的独立反应,获得了可供实用的宏观动力学方程,并讨论了反应条件对甲醇合成效率因子的影响.     

沉淀铁挤条F-T合成催化剂WGS反应考察

采用固定床积分反应器， 在工业条件下 （５００ ｈ－ １， １ ＭＰａ～２．６ ＭＰａ）， 对挤条Ｆｅ－Ｃｕ－Ｋ工业催化剂进行了水煤气变换反应性和ＦＴ反应产物分布链增长几率的考察． 在稳态下， 保持一定的轴向温度分布， 求得宏观动力学方程， 与实验数据符合较好．     

高浓度CO变换制氢催化剂本征动力学

采用石英玻璃管式反应器,考察B112型高温变换催化剂在高浓度CO(体积分率高于75%)氛围下的本征动力学特性,拟合实验数据并建立动力学模型,对幂函数动力学模型进行检验。结果表明:与传统铁系高温变换催化剂相比,该高温变换催化剂上变换反应活化能较低,其低温活性较好;该催化剂上CO对反应速率的影响偏小,是由反应组分中较高浓度的CO所导致;H_2O对反应速率的影响相对较大;CO_2对变换反应速率的抑制作用很大,因此为提高变换反应速率,应当减小CO_2的不利影响;H_2组分对反应速率的影响很小,实际应用中可以忽略。     

丙烯水合制异丙醇反应器的放大设计与投产

一、前言丙烯直接水合异丙醇的试验研究工作,由中国科学院山东化学研究所及化工部大连制碱研究所进行,他们对固相磷酸体系催化剂的制备以及反应条件作了详细实验,但未推荐该催化剂在丙烯水合过程的动力学方程。随着石油化工产品需求量日益增长,决定建设万吨级绝热固定床丙烯水合异丙醇装置,该装置设计的重点是反应器。由于绝热固定床沿着轴向床层不同断面的空速及其参与反应物组成均为一变值,所以,如果物料单纯按照反应器进口状态及其空速进行整个床层设计,显然不够严密。而采用动力学放大则比较可靠,     

CO+H_2合成甲醇、二甲醚过程及其动力学研究——(Ⅰ) 实验部分

本文采用固定床等温积分反应器,在Cu-Zn-Al和γ-Al_2O_3构成的复合催化剂上,考察了扩散和反应条件对CO+H_2合成甲醇、二甲醚的影响,获得了一批动力学实验数据。为得到高的CO转化率和CH_3OH+DME总收率,最佳反应条件是:反应温度260℃;压力5.0MPa;空速3000ml/gcat/h;原料气中H_2/CO=2;CO_2=2～4%;催化剂配比α=0.5     

绝热固定床反应器的乙醇脱水制乙烯反应工艺

为开发新型生物质乙醇脱水制乙烯反应工艺,采用了上海石油化工研究院开发的氧化铝催化剂,在绝热床反应器中进行了工艺实验优化研究。考察了不同水醇质量比、空速和反应器进口温度等对乙醇转化率和乙烯选择性的影响,应用该实验数据,结合前期建立的该催化剂上的乙醇脱水催化反应本征动力学,对该催化剂上的乙醇脱水催化反应本征动力学方程系数进行校正,计算出关于关键组分的该催化剂的效率因子,建立了更适宜于工业应用的宏观动力学模型,模型计算结果与实验数据吻合较好。相对于等温固定床反应工艺或单段绝热床反应工艺,所研发的氧化铝催化剂上四段绝热床反应工艺的能耗降低,乙醇转化率提高,乙烯选择性得到很大的提高,为工业反应器的优化设计以及放大提供必须的工艺设计数据。     

乙炔法气相合成醋酸乙烯工业固定床反应器优化操作的研究

用非等温固定反应器，参照工业生产条件，对新型Ｚｎ（Ａｃ）２一活性炭催化剂上合成醋酸乙烯的宏观动力学进行了实验研究。对实验数据进行计算机模拟的结果表明，在实际条件范围内乙炔与醋酸在新鲜催化剂上的反应速率仅与乙炔的分压有关，并且假设该反应为１级反应时，实验数据的拟合精度能充分满足要求。由此导出了相应的宏观反应动力学方程，为进一步研究该反应的失活动力学和建立工业固定床反应器模型提供了有关的基础方程和数据     

乙炔法气相合成醋酸乙烯工业固定床反应器优化操作的研究（Ⅰ）乙炔、醋酸在Zn（Ac）2—活性炭催化剂上合成醋酸乙烯反应的宏观动力学

用非等温固定床反应器，参照工业生产条件（反应温度为１６０～２１０℃、进口乙炔气与醋酸的摩尔比为５～９），对新型Ｚｎ（Ａｃ）２—活性炭催化剂上合成醋酸乙烯的宏观动力学进行了实验研究。对实验数据进行计算机模拟的结果表明，在实验条件范围内乙炔与醋酸在新鲜催化剂上的反应速率仅与乙炔的分压有关，并且假设该反应为１级反应时，实验数据的拟合精度能充分满足要求。由此导出了相应的宏观反应动力学方程，为进一步研究该反应的失活动力学和建立工业固定床反应器模型提供了有关的基础方程和数据。     

Estimation of Kinetic Parameters for Hydrogenation Reactions Using a Genetic Algorithm

The kinetics of acetylene hydrogenation in a fixed‐bed reactor of a commercial Pd/Al₂O₃ catalyst has been studied. The hydrogenation reactor considered in this work is an essential part of a vinyl chloride monomer (VCM) plant. Three well‐known kinetic models were used to simulate the hydrogenation reactor under industrial operating conditions. Since none of the models provide appropriate prediction, the industrial data and calculated values were compared and optimum kinetic parameters were evaluated utilizing a genetic algorithm (GA) technique. The best kinetic parameters for the three models were determined under specified industrial operating conditions. The hydrogenation reactor was simulated using the estimated optimum kinetic parameters of the three models. Simulation results from the three models were compared to industrial data and the best kinetic model was found. This kinetic model with the evaluated optimum kinetic parameters can well predict the behavior of the industrial hydrogenation reactor to improve the performance of the process.     

Captive sample reactor for kinetic studies of coal pyrolysis and hydropyrolysis on short time scales

An apparatus has been designed for kinetic studies of coal devolatilization under closely controlled heating rates, temperatures, and pressures. The reactor system employs a wire-mesh pyrolysis furnace driven by an electronically-controlled power supply to ensure uniform heating rates and precise crossover to a variable length isothermal period; a rapid quenching scheme permits resolution of kinetic processes in 0.1 s intervals, extending the sensitivity of kinetic measurements from the initial stage of pyrolysis through to completion of primary devolatilization. Time-resolved kinetic studies on a bituminous coal in vacuo (13 Pa) and under helium (0.22 MPa) illustrate the operation of the reactor.     

Performance Enhancement by Unsteady‐State Reactor Operation: Theoretical Analysis for Two‐Sites Kinetic Model

Theoretical analysis of the reactor performance under unsteady‐state conditions was carried out. The reactions are described by two kinetic models, which involve the participation in catalytic reaction of two types of active sites. The kinetic model I assumes the blocking of one of the active sites by a reactant, and the kinetic model II suggests a transformation of active sites of one type into another under the influence of the reaction temperature. The unsteady‐state conditions on the catalyst surface are supposed to be created (i) by forced oscillations of temperature and concentration in the reactor inlet (periodic operation of reactor) and (ii) by catalyst circulation between two reactors in a dual‐reactor system (spatial regulation). The influence of various parameters like concentration of reactant, cycle split, length of period of forced oscillations, temperatures and the ratio of catalyst volumes in the dual‐reactor was investigated with respect to the yield of the desired product. It is shown that for both cases of unsteady‐state conditions (periodic reactor operation as well as in a dual‐reactor system), a mean reaction rate predicted by the kinetic model I was up to two times higher than the steady‐state value. The kinetic model II shows a 20 % increase of the selectivity towards the desired product.     

Kinetics and Modeling of Fatty Alcohol Ethoxylation in an Industrial Spray Loop Reactor

The kinetics of the ethoxylation of fatty alcohols catalyzed by potassium hydroxide was studied to obtain the rate constants for modeling of the industrial process. Experimental data obtained in a lab‐scale semibatch autoclave reactor were used to evaluate kinetic and equilibrium parameters. The kinetic model was employed to model the performance of an industrial‐scale spray tower reactor for fatty alcohol ethoxylation. The reactor model considers that mass transfer and reaction occur independently in two distinct zones of the reactor. Good agreement between the model predictions and real data was found. These findings confirm the reliability of the kinetic and reactor model for simulating fatty alcohol ethoxylation processes under industrial conditions.     

BEHAVIOUR OF AN ADIABATIC PACKED BED REACTOR PART 2: MODELLING

The steady state and dynamic behaviour of an adiabatic packed bed reactor for the selective hydrogenation of mixtures of ethyne and ethene is studied. A heterogeneous model with axial dispersion of heat is solved numerically by means of a fully implicit discretisation scheme. From an analysis of the inlet and outlet boundary conditions, it follows that in order to avoid an influence of the type of boundary condition on the reactor behaviour, sufficiently long inert zones before and after the active bed should be present. Using preliminary kinetic expressions adapted from Mcn'shchikov ct al. (1975), the model calculations show a reasonable agreement with the experiments performed in a laboratory scale reactor and demonstrate the importance influence of small amounts of carbon monoxide both on the steady state as well as on the transient behaviour of the reactor. However, using the rate expressions derived from our own kinetic experiments in a Berty reactor, the behaviour under runaway conditions and the transition from non-runaway to runaway conditions can not be described well. Several factors that contribute to this discrepancy are discussed. This work shows that, in particular for a complex reaction system such as the selective hydrogenation of ethyne in ethene, the limited accuracy of the kinetic model and kinetic parameters dominates the precision attainable with packed bed reactor models.     

CO气相催化偶联合成草酸二甲酯的原位红外及动力学研究

文章研究了在常压下,CO在钯催化剂上与亚硝酸甲酯气相催化偶联制草酸二甲酯的反应动力学。为了消除催化剂床层中的浓度梯度和温度梯度,较好地揭示反应的本征动力学规律,动力学的考察在无梯度反应器中进行。根据原位红外实验结果分析提出反应机理模型和实验测得的CO转化率与温度,空速,原料配比的关系,对模型进行拟合优化,导出了动力学方程。结果表明,CO的吸附为整个反应的控制步骤。     

基于阶跃射流的撞击流反应器流场动态特性分析

利用实验与数值模拟方法对动态阶跃型撞击流反应器流场特性进行研究,分析不同入口速度条件下流体流动规律、湍流特性以及能量水平。结果表明,动态阶跃型入口条件下,撞击面在两喷嘴之间周期性移动,流动参数也会发生周期性变化。随着入口平均速率的增大,驻点速度逐渐增大;随着两喷嘴入口速率差的增加,撞击面移动速度加快,撞击区流体湍流强度逐渐增加;随着入口平均速率与入口速率差的增大,XOZ平面在一个周期内的平均湍动能逐渐减小。对比动态撞击流反应器与稳态撞击流反应器内流场特性,探究动态入口条件对撞击流反应器流场特性的影响。结果表明,动态阶跃撞击流反应器湍流黏度、湍流强度和湍动能等参数均明显高于稳态撞击流反应器,撞击轴线上的湍动能梯度分布大于稳态撞击流反应器。动态入口条件下撞击流反应器流体湍动更剧烈,能量水平更高,有利于增加流场内流体扰动与促进混合。     

Analysis of deactivation disguised kinetics in transport reactors by periodic operation

Deactivation disguised kinetic schemes in an isothermal transport reactor are differentiated by means of periodic operation of the reactor. A periodic rectangular pulse is assumed for the inlet concentration. Three numerical examples are given to demonstrate that the deactivation disguised kinetic models give different conversions under periodic operation.     

Kinetic study of olefin polymerization with a supported metallocene catalyst. III. Ethylene homopolymerization in slurry

A kinetic study of ethylene homopolymerization is conducted with a supported unbridged metallocene catalyst in a slurry reactor. The effects of operational parameters such as the reaction temperature and pressure on kinetics are investigated. The kinetic parameters which have been determined for this particular catalyst from previous gas phase studies are used in a slurry reactor model to predict the polymerization behavior under various reaction conditions. The experimental data compare favorably with the predictions from this model. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2901–2917, 2001     

Kinetic Data for Continuous Processes from Liquid-Liquid Loop Reactor Experiments

Process engineering is based on models, which are preferably established at laboratory scale under near-service conditions. Here, for the first time, a kinetic study of the basic hydrolysis of ethyl acetate was performed with a small volume liquid-liquid loop reactor satisfying these criteria. The activation energy and pre-exponential factor were determined that agreed with data from the literature. Acquired data could be successfully transferred to well-established ideal reactor models such as continuous stirred tank or plug flow reactors. It was, thus, possible to show that a simply scalable loop reactor, requiring only small amounts of substrate and producing minimum waste, can serve as a tool for kinetic studies of continuous processes.