结构催化剂与反应器:新结构、新策略和新进展

具有3D非规则空隙结构的foam/fiber基体不仅导热性好、面体比更大,而且在消除径向扩散限制、涡流强化传质/传热、提高接触效率、几何构型灵活设计等方面显示出传统的规则2D空隙蜂窝和微通道结构难以企及的优势,但其高效催化功能化还面临挑战,近年来,相关的研究与开发日益受到重视且进展明显。本文综述了foam/fiber新型结构催化剂的"宏-微-纳"一体化"非涂层"构筑及其在涉及能源化工和环境催化等的典型强吸（放）热和/或高通量反应过程中的应用等方面的研究新进展,以期为诸如C1能源化工等众多反应过程中存在的强烈热/质传递限制等问题的解决,以及为满足环境催化和"模块"化工厂等对高通量、低压降等的特殊要求提供新的思路和技术支撑。     

基于CFX的规整催化剂甲烷化反应器流场模拟与结构优化

煤制天然气可有效解决天然气消耗量持续增加、环保等问题。甲烷化反应是煤制天然气重要环节。在众多甲烷化催化剂中,规整催化剂由于传热、传质、反应特性、压降性能良好,受到广泛关注。而规整结构催化剂的孔道独立,与反应器轴线垂直截面的流场均匀度对产物产率影响很大。基于CFX以反应器内流场均匀度为目标,对规整催化剂固定床甲烷化反应器进行冷态数值模拟,获得最优反应器结构。     

旋转泡沫填料反应器的研究进展

旋转泡沫填料反应器是一种新型多相搅拌釜式反应器,其将传统的搅拌桨替换成圆环型泡沫填料,可有效强化反应器内多相间传质混合过程,且多孔填料可作为催化剂载体,能减小多相催化反应中固体催化剂的使用量,具有替换传统多相搅拌釜式反应器和浆态反应器的潜力,将有较好的应用前景。本文详细阐述了旋转泡沫填料反应器的结构和反应器内多相流动形式,着重介绍了反应器内多相流动特性的研究进展及反应器内传质性能的研究现状,并与传统的多相反应器传质性能进行比较;从应用方面分析了反应器用于葡萄糖催化氧化、苯乙烯催化加氢等多相过程的强化方式及优势,通过对比得出旋转泡沫填料反应器能有效降低化工过程中物耗、提高物料的利用率;介绍了与旋转泡沫填料反应器类似的其他多孔式搅拌桨反应器的研究进展,分析了这类反应器的优势,并对其性能进行对比;最后,对旋转泡沫填料反应器研究的不足及未来的发展进行了阐述和展望。     

乙苯脱氢规整反应器的模拟研究

采用COMSOL Multiphysics软件对规整及散堆固定床反应器内的乙苯脱氢反应进行了模拟计算,对比了等温和绝热条件下2种反应器的性能,研究了反应器串联段数、工艺条件、催化剂结构对绝热规整反应器内乙苯脱氢反应性能的影响。结果表明:等温和绝热条件下,与颗粒散堆固定床相比,规整反应器的乙苯转化率更高、苯乙烯选择性更高、反应器压降更小。进料温度为893 K、压力为104 k Pa时,绝热规整反应器中乙苯转化率为54.81%,苯乙烯选择性为94.84%,而绝热散堆固定床仅为39.55%和92.52%。对于绝热规整反应器,三段工艺的乙苯转化率和苯乙烯收率比一段或二段工艺高;升高温度、降低压力可以提高乙苯转化率,且较低的温度和压力可得到较高的苯乙烯选择性;减小催化剂孔壁厚度可以得到更高的乙苯转化率和苯乙烯选择性,适宜孔壁厚度为0.2 mm;催化剂孔密度对反应性能几乎没影响。     

“催化接触器”型膜反应器的研究进展

对膜反应器按照流体流动方式进行分类，并对“催化接触器”型膜反应器的构成、特点与优点、多孔催化膜的制备、应用反应体系的研究状况进行综述。由于“催化接触器”型膜反应器在强化传质和消除孔内扩散方面表现出的优势，在流固相催化反应中显示出良好的应用前景。     

环流反应器的流动、混合与传递特性

由于环流反应器内存在定向循环,与鼓泡塔反应器相比,其混合性能大幅提升,已广泛应用于许多工业过程,如发酵、反应器结晶等工业过程,近年来成为国内外学者研究的热点。针对环流反应器内操作条件下的流动形态、流体力学(包括相含率分布、循环液速、混合时间以及离集指数等)及传质/传热特性,总结了其最新研究进展,分析了相含率尤其是固含率变化对反应器中关键参数如循环液速和化学反应速率的影响,展望了从机理上研究相互耦合的多相流动、传质/传热和化学反应规律,为进一步推动其工业应用提供参考。     

环流反应器的流动、混合与传递特性

由于环流反应器内存在定向循环,与鼓泡塔反应器相比,其混合性能大幅提升,已广泛应用于许多工业过程,如发酵、反应器结晶等工业过程,近年来成为国内外学者研究的热点。针对环流反应器内操作条件下的流动形态、流体力学（包括相含率分布、循环液速、混合时间以及离集指数等）及传质/传热特性,总结了其最新研究进展,分析了相含率尤其是固含率变化对反应器中关键参数如循环液速和化学反应速率的影响,展望了从机理上研究相互耦合的多相流动、传质/传热和化学反应规律,为进一步推动其工业应用提供参考。     

聚丙烯催化剂体系及聚合调控研究进展

综述了聚丙烯催化剂的发展历程,重点介绍齐格勒-纳塔催化剂、茂金属催化剂和非茂金属催化剂的研究进展,以及评述影响催化剂性能的因素并给出典型实例。分别探讨了不同种类的催化结构调控生成结构多样聚丙烯的方法。最后对各种聚丙烯催化剂特点和改进方向进行了总结。     

规整填料传质性能计算的研究进展

综述了规整填料传质性能的计算方法和模型,并对这些模型的理论基础和适用条件进行了分析和比较。归纳了近年来对于传统规整填料传质模型的修正和扩展,并对影响传质性能的有效比表面积的经验关联式进行了讨论,指出了规整填料传质性能研究方面进一步的探索方向和应改进的若干问题。     

结构化多相反应器内泰勒流的液侧传质特性

采用定态溶氧法,实验测定了结构化反应器内的液侧体积传质系数.考察了表观气、液速度对液侧体积传质系数的影响,比较了三种不同孔密度的结构化载体(50、100和400 cpsi)内的液侧体积传质系数.结果表明,在实验的操作条件下,床层内的液侧体积传质系数随液体表观速度增大而增大:同-液速下,随气体表观速度增大亦增大.比较不同...     

金属基整体式催化剂的研究进展

系统地介绍了金属基整体式催化剂的结构、制备、性能及其数值模拟方面的研究进展,阐述了该类催化剂在工业催化领域中的应用。通过对研究现状的分析,提出了金属基整体式催化剂的制备仍需进一步解决的几个关键问题,指出金属基整体式催化剂在吸/放热反应耦合过程中的应用极具发展潜力。     

整体式催化剂性能及应用的研究进展

由整体式催化剂的结构特点出发．系统地阐述了整体式催化剂具有的一系列超越传统颗粒状催化剂的独特优越性,提出了其在三相反应中有待解决的几个关键性问题。同时概述了整体式催化剂在环保领域和化工产品合成领域的应用、研究现状和展望。     

Analysis of Membrane Reactors for Integrated Coupling of Oxidative and Thermal Dehydrogenation of Propane

This study presents strategies capable to intensify the thermal dehydrogenation of propane (TDH) using integrated reactor concepts. An inert packed bed membrane reactor for distributed dosing of oxygen to realize the oxidative dehydrogenation (ODH) was studied and compared to a reactor with catalytically active membrane. The latter concept allows to combine TDH and ODH in one apparatus to overcome the chemical equilibrium by in situ conversion of the by‐product H₂ using O₂ or in a reverse water‐gas shift reaction by CO₂. If CO₂ is used as active sweep gas the reactor offered better performance regarding yield and selectivity. Strategies for further thermal integration are discussed.     

活性组分负载量对CuO-CeO_2/Cord.整体式催化剂性能的影响

蜂窝状的堇青石载体经20%的草酸溶液沸煮预处理后,采用共浸渍法制备了CuO-CeO2/Cord.整体式催化剂,分别考察了不同活性组分CuO-CeO2负载量对催化剂性能的影响,并运用X射线衍射(XRD)、程序升温还原技术(TPR)对样品进行了表征。测试结果表明不同的活性组分负载量对催化剂性能均有一定影响,当CuO-CeO2负载量为15%时催化剂表现出了最好的活性和选择性。     

流化床反应器过程强化技术

Fluidized beds enable good solids mixing, high rates of heat and mass transfer, and large throughputs, but there remain issues related to fluidization quality and scale-up. In this work I review modification techniques for fluidized beds from the perspective of the principles of process intensification (PI), that is, effective bubbling sup-pression and elutriation control. These techniques are further refined into (1) design factors, e.g. modifying the bed configuration, or the application of internal and external forces, and (2) operational factors, including altering the particle properties (e.g. size, density, surface area) and fluidizing gas properties (e.g. density, viscosity, or velocity). As far as two proposed PI principles are concerned, our review suggests that it ought to be possible to gain improve-ments of between 2 and 4 times over conventional fluidized bed designs by the application of these techniques.     

Multiphase surfactant-assisted reaction-separation system in a microchannel reactor

The Lewis acid-catalyzed addition of trimethylsilyl cyanide to p-chlorobenzaldehyde in a microchannel reactor was investigated. The microchannel was integrated to promote both reaction and separation of the biphase system. FeF₃ and Cu(triflate)₂ were used as water-stable Lewis acid catalysts. Sodium dodecyl sulfate was incorporated in the organic-aqueous system to enhance the reactivity and to manipulate the multiphase flow inside the microchannel. It was found that the dynamics and the kinetics of the multiphase reaction were affected by the new micellar system. Parallel multiphase flow inside the microchannel was obtained, allowing for continuous and acceptable phase separation. Enhanced selectivity was achieved by operating at lower conversion values.     

多孔陶瓷膜反应器用于非均相超细纳米催化的研究进展(英文)

Heterogeneous catalysts with ultrafine or nano particle size have currently attracted considerable attentions in the chemical and petrochemical production processes, but their large-scale applications remain challenging because of difficulties associated with their efficient separation from the reaction slurry. A porous ceramic membrane reactor has emerged as a promising method to solve the problem concerning catalysts separation in situ from the reaction mixture and make the production process continuous in heterogeneous catalysis. This article presents a review of the present progress on porous ceramic membrane reactors for heterogeneous catalysis, which covers classification of configurations of porous ceramic membrane reactor, major considerations and some important industrial applications. A special emphasis is paid to major considerations in term of application-oriented ceramic membrane design, optimization of ceramic membrane reactor performance and membrane fouling mechanism. Finally, brief concluding remarks on porous ceramic membrane reactors are given and possible future research interests are also outlined.     

Systematic Investigations of Vibrational and Fluid-Mechanical Stability of Coated Monolithic Catalysts

Heterogeneous catalysts usually consist of porous, inorganic materials. Especially in the mobile application, e.g., in exhaust gas catalysis as a part of the gas line of an engine, there are loads due to vibrations and high gas velocities. It can be assumed that physical stress will lead to a loss of the catalytically active coating. The present contribution describes experimental setups and methods for a systematic and reproducible investigation of the main influences to the mass loss due to vibrational and fluid-mechanical stress caused by particle-free gas flows.