甲醇脱水制二甲醚绝热固定床反应器模拟设计

提出了绝热固定床二甲醚反应器的数学模型，利用该模型对目前工业使用的绝热型二甲醚反应器的计算表明，模拟计算与实际二甲醚反应器的操作吻合。同时还计算考察了压力，进口气体温度与流量对反应器操作的影响。     

三段串联绝热轴向氨合成塔的模拟计算和设计优化

提出三段轴向氨合成反应器的数学模型和设计优化方法，对三段轴向氨合成反应器进行模拟计算。同时计算了操作压力分别为１５７８，１５０，１００，７．５ＭＰａ时，在三段串联绝热轴向反应器中满足日产１０００ｔ氨所需的最少催化剂用量。     

AF—5分子筛催化剂上苯气相乙基化反应的失活动力学研究…

在绝热固定床实验反应器中对苯和乙烯在ＡＦ－５分子筛催化剂上进行的烷基化反应的失活动力学作了研究。初步考察表明乙烯和苯都会引起失活，但乙烯引起的失活是主要的。在和工业反应器类似的操作条件下系统测定了由催化剂失活引起的乙烯转化率随操作时间的变化，所得数据将用于建立失活动力学模型。     

非绝热式固定床反应器的参数敏感性及热失控临界参数

寻找安全有效的反应条件一直是绿色化工的重要研究内容之一。采用邻二甲苯氧化的反应动力学模型,分析了非绝热式固定床反应器的参数灵敏性和热失控行为,考察了非绝热式固定床反应器温度对冷却介质流量、进料温度和初始压力的敏感性。模拟计算结果表明,当反应进入敏感性区域后,反应器对冷却介质流量、进料温度和初始压力的改变极其敏感。采用系统散度判据（div>0）计算该反应的热失控临界操作参数,计算结果与文献中的判据进行了分析比较,得到类似的结果,但计算更简单。考虑冷却介质的影响,修正了div判据,得到更准确的热失控临界操作参数。研究结果表明,此判据能为反应器的设计及过程控制提供重要的参考依据。     

苯与乙烯在ZSM－5上的烷基化反应（Ⅲ）固定床反应器行为的化较

给出了低浓度乙烯和苯在ＺＳＭ－５型分子筛催化剂上的宏观动力学方程。建立了中试固定床反应器模型。模型值与中试结果相一致。化较了单段绝热床、等温床和多段绝热床反应器行为。结果表明：在达到乙烯９５％转化率时，苯生成乙苯和乙烯生成乙苯的选择性为等温床要化单段绝热床好；四段绝热床可达到与等温床相当的指标。考虑到绝热床投资少，操作简单，可变性强，四段绝热床反应器应该是首选的反应装置。     

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。     

常压水燃气部分甲烷化多段绝热反应器平衡计算模型

阐明常压水煤气部分甲烷多段绝热反应器物料平衡，能量平衡和化学反应平衡的计算模型，并采用逆流计算法，给出了满足城市煤气热值和ＣＯ量要求的多段绝热反应器的平衡计算示例。     

AF-5分子筛催化剂上苯气相乙基化反应的失活动力学研究——(Ⅰ)实验研究

在绝热固定床实验反应器中对苯和乙烯在 AF-5分子筛催化剂上进行的烷基化反应的失活动力学作了研究。初步考察表明乙烯和苯都会引起失活,但乙烯引起的失活是主要的。在和工业反应器类似的操作条件下系统测定了由催化剂失活引起的乙烯转化率随操作时间的变化。所得数据将用于建立失活动力学模型。     

丁二烯氯化制氯丁二烯的研究——Ⅰ、丁二烯氯化制氯丁二烯小试报告

在管式反应器中,试验了丁二烯气相热氯化反应的条件,并着重研究了氯化反应的特征,为选择适宜的反应器型式、结构和操作方式提供了依据。然后,在推荐的双喷咀二段式绝热反应器中研究了丁二烯气相热氯化反应的工艺条件。     

甲醇在改性分子筛催化剂上脱水生成二甲醚

测定了工艺条件对甲醇在ＣＭ－３－１ 型改性分子筛催化剂上脱水生成二甲醚转化率的影响,对现用绝热式反应器进行改进,提出自热型与均温型两类新型二甲醚反应器,设计了两类反应器的结构、尺寸和操作条件。     

绝热固定床反应器的研究——(Ⅱ)床内定态温度分布

本文运用一维非均相动态模型,研究了绝热固定床反应器床内定态温度分布问题.由于床内温度分布直接关系到反应器内高温区长度,因而对温度分布影响因素的研究甚为重要.本研究分别阐明了催化剂层、气体及器壁导热对床层温度分布的影响,并以实例予以说明.研究表明,实验型反应器器壁导热的影响不容忽视,因而将实验数据用于放大时必须考虑器壁导热的影响.     

MULTIPLE STEADY STATES OF ADIABATIC FIXED-BED REACTORS

Singularity theory is applied to a steady state heterogeneous fixed-bed reactor model in which backconduction of heat through the catalyst is assumed. A maximum of five solutions exist when either adiabatic or Danckwerts boundary conditions are assumed for the catalyst temperature although heat loss at the bed inlet increases the exothermicity of the reaction required for five solutions to exist. An empirical uniqueness criteria for this model, based on the zero and infinite solid phase conductivity limiting cases, is presented.     

板翅往复流道间的传热与流阻性能研究

提出了一种板翅式内部换热紧凑型SO2转化反应器,兼顾了绝热式反应器和连续换热式反应器二者的优点,可实现节能、节材和环保的目的,并可节约大量操作费用。对板翅往复流道中的气体换热及流阻特性进行了实验研究及理论分析,探讨了板翅结构对传热及流阻的影响,得到了优化设计数据。结果表明,本研究构造的板翅往复流道具有良好的综合传热效果,可广泛用于硫酸转化系统等气固反应装置中。     

BEHAVIOUR OF AN ADIABATIC PACKED BED REACTOR PART 1: EXPERIMENTAL STUDY

The steady state and dynamic behaviour of an adiabatic packed bed reactor for the selective hydrogenation of ethyne and ethene mixtures was studied experimentally. Different methods to achieve adiabatic conditions on a laboratory scale were tested. Temperature profiles of both the gas and solid phase as well as local temperature differences between the two phases were measured. For hydrogenation in the absence of carbon monoxide the selectivity was always poor. Also, in that case, the temperature in the reaction zone exhibited oscillatory behaviour. On addition of CO, the oscillations disappeared and the selectivity improved. For a given set of operating conditions there existed a relatively small range of CO contents with good selectivity and satisfactory conversion. This range depends strongly on the inlet temperature. The dynamic response of the reactor to changes in the CO content showed a considerable wrong-way behaviour. This high sensitivity to fluctuations in the CO content, found for our experimental reactor, indicates a probable cause for a thermal runaway in industrial practice.     

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.     

Transients in adiabatic tubular reactors. Axial dispersion models with well-mixed appended sections

Using boundary conditions more general than those due to Danckwerts, the authors recently showed that significant variations may be encountered in the global stability characteristics of an axially dispersed adiabatic tubular reactor. The numerical results presented in this communication demonstra that for a fixed initial state of the reactor, steady states very different from those predicted with Danckwerts conditions are reached depending on th initial state of the reactor appendages. The cases where the reactor is preceded or succeeded by well-mixed (non-reactive) sections are considered. The findings will be very useful in regulation of the dynamics of tubular reactors.     

What is the leanest stream to sustain a nonadiabatic loop reactor: Analysis and methane combustion experiments

While previous studies experimentally demonstrated that loop reactor (LR) can be sustained with a lean feed (using ethylene combustion) and have analyzed the single‐reaction adiabatic case, this work analyzes the effects of heat loss and of reactor size to determine the leanest stream (expressed in terms of adiabatic temperature rise ΔT_lim) that will sustain the operation. For an adiabatic infinitely long reactor ΔT_lim→0 while for a finite reactor ΔT_lim scales as (1 + Pe/4)^?1 where Pe = Luρc_pf/k, and heat loss increases this limit by (β/Pe)^1/2. Thus, a good design of a LR will aim to decrease conductivity (k) and radial heat‐transfer coefficient (β) while increasing throughput (u) and reactor length. This article is also the first experimental demonstration of auto‐thermal operation in a LR for catalytic abatement of low‐concentration of methane, showing the leanest stream to be of 8000 ppm vs. 33,000 ppm in a once‐through reactor. Experimental combustion results of methane and of ethylene are compared with model predictions. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2030–2042, 2017     

Conversions and temperature rises in a tubular flow reactor with uncontrolled wall heat transfer

A study has been made of the acetic anhydride-water reaction in a flow reactor where there was heat loss from the reactor wall. Runs were carried out at varying inlet acetic anhydride concentrations and Reynolds numbers. The laminar flow model with heat loss at the wall was found to give good agreement with experimentally observed conversions and overall temperature rises. In addition, predicted radial profiles for this model gave a better representation of measured temperature profiles than had been obtained when assuming reaction conditions were adiabatic.     

Experimental study of traveling waves in nonadiabatic fixed bed reactors for the oxidation of carbon monoxide

An experimental study of axial temperature profiles in a nonadiabatic tubular fixed bed reactor has been made under the transient operation. The catalytic carbon monoxide oxidation occuring on a Pt/alumina catalyst has been used. Unlike the adiabatic conditions the velocity of a traveling temperature wave in a nonadiabatical arrangement depends on its axial position. In certain regions of inlet concentration multiple temperature fronts have been observed. For low inlet CO concentration a downstream temperature wave results and the lower (kinetic) steady state is dominant. For high inlet CO concentration an upstream propagating front results and the upper steady state is dominant. For a downstream moving wave oscillations of wave velocity, hot spot temperature and exit conversion have been measured. For certain operating conditions periodic behavior of temperature profiles in the reactor has been observed.     

The behaviour of an adiabatic fixed bed reactor for the oxidation of carbon monoxide—I: General parametric studies

An experimental study of an adiabatic catalytic fixed bed reactor has been made under both transient and steady state operation. Temperature measurements have been made within the bed and within two instrumented pellets placed inside the bed. Concentration profiles have also been measured in the bed under steady state conditions. A general parametric investigation was made which also included the effect of reverse operation. Intraparticle temperatures were small even in the ignition zone but could be adequately predicted if local variables were used. Good agreement was obtained between the experimental results and a heterogeneous dispersion model.