微通道反应器在芳香化合物硝化反应中的应用进展

芳香化合物的硝化是常用的生产单元,采用传统釜式反应器进行硝化反应存在放热量大、选择性低、浪费资源、污染环境、存在安全隐患等问题。微通道反应器具有优良的传热、传质性能,可有效解决传统釜式反应器存在的问题,是一种安全、环保、高效的新型反应设备。综述了微通道反应器在芳香化合物硝化反应中的应用进展,包括以苯型芳香烃为底物的硝化反应及以非苯型芳香烃为底物的硝化反应。     

连续微反应加氢技术在有机合成中的研究进展

加氢反应是有机合成中很常见的一种反应类型,采用常规的间歇加氢釜具有反应效率低、操作烦琐和安全性差等问题。而连续加氢微反应器进行非均相催化加氢反应能提供更高的传质性能,催化剂的回收利用与产物的纯化也更为方便,能极大地提高生产效率,减少贵金属催化剂的损失。因为这些优点,连续微反应加氢技术得到了越来越多的关注。本文阐述了连续微反应加氢技术中常用的微反应器与固体金属催化剂类型,以及不同官能团非均相高效催化加氢的研究进展,在此基础,对该技术在精细化工领域的应用进行了展望。连续微反应加氢技术使得加氢过程可以在更安全、更高效、更环保的条件下完成,具有很高的工业应用价值,是未来化学化工领域重点发展的方向之一。     

微反应器内连续重氮化/偶合反应进展

微反应器一般是指通过微加工和精密加工技术制造的小型反应器,其为微化工技术的核心部件之一。与传统的釜式反应器相比,微反应器具有很大的优势,顺应了高技术含量和可持续发展的要求。在化学化工、材料、生物等诸多领域的研究和生产过程中,微反应器都有着广泛的应用前景,这其中一大部分涉及到了危险或不稳定物质的合成过程及高放热反应过程等。本文主要介绍了国内外利用微反应器技术进行重氮化反应连续化的研究进展,以及利用微反应器进行连续重氮化/偶合反应合成偶氮染料及颜料的研究进展。微反应器技术使化学反应过程变得更快速、更安全、更环保,所以具有很高的工业应用价值,也是化工领域未来的发展方向之一。     

连续微反应加氢技术在有机合成中的研究进展

加氢反应是有机合成中很常见的一种反应类型,采用常规的间歇加氢釜具有反应效率低、操作烦琐和安全性差等问题。而连续加氢微反应器进行非均相催化加氢反应能提供更高的传质性能,催化剂的回收利用与产物的纯化也更为方便,能极大地提高生产效率,减少贵金属催化剂的损失。因为这些优点,连续微反应加氢技术得到了越来越多的关注。本文阐述了连续微反应加氢技术中常用的微反应器与固体金属催化剂类型,以及不同官能团非均相高效催化加氢的研究进展,在此基础,对该技术在精细化工领域的应用进行了展望。连续微反应加氢技术使得加氢过程可以在更安全、更高效、更环保的条件下完成,具有很高的工业应用价值,是未来化学化工领域重点发展的方向之一。     

连续流重氮化反应技术研究进展

重氮化反应在染料、药物和精细化工等领域应用广泛,传统的釜式重氮化存在产品收率低、中间体不稳定、反应放出大量热等问题.连续流反应技术是一种将危险工艺安全化的途径,本文对连续流重氮化反应技术的应用进行概述.     

微通道反应器中精细化学品合成危险工艺研究进展

卤化、氧化、重氮化、硝化以及催化加氢是精细化工生产中的重要反应,通常以间歇方式在釜式反应器中进行,存在安全隐患,并且反应效率低。微通道反应器技术的发展为解决上述问题提供了有效途径,因此,发展基于微通道反应器的安全高效合成工艺成为当前精细化工领域的研究热点之一。该文综述了近年来微通道反应器中涉及精细化工产品合成危险工艺的研究进展,并指出了微通道反应器存在的不足和今后研究的方向。     

离子液体在有机氟化反应中的应用

离子液体作为新型高效的溶剂及催化剂,已成为“绿色”化学的重要研究内容和热点.对近10年来离子液体在有机氟化反应中的应用进行了综述,重点介绍了电化学氟化反应、亲电氟化反应和亲核氟化反应等.     

光化学微反应技术的基础及研究进展

光化学转化是有效利用光能实现化学反应的重要途径,微反应技术为提高其过程效率提供了一个强有力的平台。本文首先指出微反应器相比于传统釜式光反应器,在光强分布、过程放大、光能利用效率等诸多方面存在明显的优势,能够实现光化学反应过程的高效强化。简要地介绍了光化学转化及光化学微反应技术的基本特征,然后系统地综述了光化学微反应器的设计构建及其在有机合成、聚合等方面的应用,并详细介绍了自动化控制的光化学微反应系统及应用。重点介绍了微反应技术在紫外光、可见光辐照下的光化学合成进展及其过程放大。最后,对光化学微反应技术的研究进展进行总结,并对其发展趋势进行了展望。     

连续微反应加氢技术在脱保护反应中的应用

保护与脱保护是医药中间体等精细化工领域中较为常见的一种有机合成策略。常用的保护基主要有苄基与苄氧羰基,通常可利用催化加氢法将其脱除。采用高压加氢间歇釜工艺存在气液传质效率低,操作安全性差,氢解效率低等问题。采用连续微反应加氢技术进行非均相催化加氢脱保护,可以利用其较高的气液传质效率和平推流特性实现高选择性脱保护,并显著缩短反应时间。本文阐述了连续微反应加氢技术在脱保护反应中的优点及其在药物中间体合成中的实际应用,并介绍了催化剂与溶剂对脱保护反应的影响。最后对连续微反应加氢技术在脱保护中的应用进行了展望。     

微反应器内连续重氮化/偶合反应进展

微反应器一般是指通过微加工和精密加工技术制造的小型反应器,其为微化工技术的核心部件之一。与传统的釜式反应器相比,微反应器具有很大的优势,顺应了高技术含量和可持续发展的要求。在化学化工、材料、生物等诸多领域的研究和生产过程中,微反应器都有着广泛的应用前景,这其中一大部分涉及到了危险或不稳定物质的合成过程及高放热反应过程等。本文主要介绍了国内外利用微反应器技术进行重氮化反应连续化的研究进展,以及利用微反应器进行连续重氮化/偶合反应合成偶氮染料及颜料的研究进展。微反应器技术使化学反应过程变得更快速、更安全、更环保,所以具有很高的工业应用价值,也是化工领域未来的发展方向之一。     

微反应器内苯甲醚连续合成

苯甲醚是一种重要的溶剂和有机合成中间体，以往通过间歇反应合成，存在生产效率低下、操作周期长等问题，亟需开发连续化的生产装置和技术。提出以苯酚钠水溶液和硫酸二甲酯为原料通过连续微反应器合成苯甲醚的方法。该方法利用微混合器和局部收缩的反应管道强化反应物的混合，在近似绝热的反应条件下快速完成反应过程。报道了苯酚钠浓度、反应物流量和反应物摩尔比对于微反应器内苯酚钠转化率和硫酸二甲酯利用率的影响规律。与文献报道的间歇反应进行了对比，揭示了微反应技术的优势。     

A circular microreaction method to the safe and efficient synthesis of 3-methylpyridine-N-oxide

3-Methylpyridine-N-oxide is an essential intermediate in the preparation of 2-chloro-5-methylpyridine, which can be used to synthesize nicotine insecticides such as imidacloprid and acetamiprid. The traditional method of production of 3-methylpyridine-N-oxide is catalytic oxidation of 3-methylpyridine in semi-batch reactors.Due to strong exothermic reaction and explosive property of 3-methylpyridine, the reaction efficiency and safety is low using batch technology. Therefore, the development of a safer and efficient 3-methylpyridine-N-oxide production process is very necessary in industrial production. In this paper, microreaction systems were introduced into the preparation of 3-methylpyridine-N-oxide. The comparison of three different methods(traditional semibatch method, co-current microreaction method, and circular microreaction method) showed that the circular microreaction method was the most applicable, with relative higher product yield(～ 90%), less side reaction and better reaction control.     

Experimental Investigation and Modeling Approach of the Phenylacetonitrile Alkylation Process in a Microreactor

The application of microreaction technology has the potential to intensify chemical processes. It is therefore of great interest to investigate the operating efficiency of a multiphase process such as the alkylation of phenylacetonitrile in a microreactor and to compare the performance to a batch reactor. The undeniable advantages of continuous microreactor systems for this process were demonstrated. Furthermore, the influence of the organic to aqueous phase ratio in the microreactor was investigated. A model of the reaction course was formulated based on experimental data. This model was used in the analysis and modeling of the alkylation process in a microreactor and found to be adequate. The optimal microreactor performance conditions were determined using the numerical optimization technique (Harrington's desirability function) and confirmed by experiments.     

Continuous deacylation of amides in a high-temperature and high-pressure microreactor

The deacylation of amides, which is widely employed in the pharmaceutical industry, is not a fast reaction under normal conditions. To intensify this reaction, a high-temperature and high-pressure continuous microreaction technology was developed, whose space-time yield was 49.4 times that of traditional batch reactions. Using the deacylation of acetanilide as a model reaction, the effects of the temperature, pressure, reaction time, molar ratio of reactants, and water composition on acetanilide conversion were carefully studied. Based on the rapid heating and cooling capabilities, the kinetics of acetanilide deacylation at high temperatures were investigated to determine the orders of reactants and activation energy. This microreaction technology was further applied to a variety of other amides to understand the influence of substituents and steric hindrance on the deacylation reaction.     

连续化微反应技术在香料、香精和化妆品合成中的应用

作为一项全新的过程强化技术,连续化微反应技术在香料、香精和化妆品合成中的应用与日俱增。综述了近年来微反应技术在香料合成研发和生产方面的进展。与传统的间歇式反应器不同,连续化微通道反应器的主要特点是连续进料、传质换热能力大大加强以及可以精确控制反应参数等。该技术在许多香料合成常用的反应中都体现出了常规反应器无法比拟的优势,同时在合成香料工业应用的成功范例也展示了微反应技术可以预见的广阔前景。     

Continuous synthesis of 4-bromo-3-methylanisole in modular microreaction system

With the development of microreaction technology and the key issues of liquid-liquid batch bromination process for the synthesis of 4-bromo-3-methylanisole, a modular microreaction system was constructed by taking microreactor and microbead-packed bed as the major functional microdevice units to intensify the bromination of methylanisole. And in this modular microreaction system, the liquid-liquid heterogeneous continuous bromination of 4-bromo-3-methylanisole was studied. The following optimized conditions were obtained, concentration of Br₂ (x_Br2): 17.5 wt%, molar ratio of Br₂ to methylanisole (n_Br2/n_M): 1.01, initial reaction temperature (T): 0℃, residence time (τ): 0.78 min, with yield of 4-bromo-3-methylanisole more than 98%, and percentage of polybrominated side product less than 1%. Comparing with the conventional batch process, the continuous microreaction technology has obvious advantages. For example, it can change the traditional batch process to a continuous one with a significant increase of productivity (space time yield: 6.5×10⁴ kg/(m³·h)). Besides, since this process is mainly controlled by mass transfer, the modular microreaction system with excellent mass transfer could reduce 50% of polybrominated side product. The study might provide a good foundation for the continuously controllable synthesis of 4-bromo-3-methylanisole in safety.     

模块化微反应系统内溴化间甲基苯甲醚连续合成

根据微化工技术发展的主要趋势，针对4-溴-3-甲基苯甲醚间歇非均相合成技术存在的问题，以微筛孔反应器与玻璃微珠填充床为核心功能微设备单元构建了模块化微反应系统，并在此模块化微反应系统内对液-液非均相连续溴化合成4-溴-3-甲基苯甲醚开展研究。通过优化操作条件，在溴浓度(x_{\mathrm{B}{\mathrm{r}}_{\mathrm{2}}})为17.5%（质量分数）、溴与间甲基苯甲醚摩尔比(n_{\mathrm{B}{\mathrm{r}}_{\mathrm{2}}}/n_M)为1.01、反应起始温度(T)为 0℃、停留时间为0.78 min条件下，4-溴-3-甲基苯甲醚的收率大于98%，多溴代副产物的含量仅为1%。与传统间歇溴化反应相比，模块化微反应系统内连续溴化反应具有十分明显的优势：可将间歇过程连续化，在保证安全的基础上极大地提升了反应的效率（时空收率为6.5×10⁴ kg/(m³·h)）；另外，该过程是由传质控制的，微反应器的传质性能优异，可极大地改善产品的选择性（多溴代副产物的量减少50%）。该研究为4-溴-3-甲基苯甲醚的连续高效安全合成提供了技术和设备依据。     

Assessment of the ecological potential of microreaction technology

The pros and cons of microreaction technology were investigated using life cycle assessment (LCA) for the first time. This evaluation method has the outstanding advantage that it takes into account the entire life cycle of a process or product from “cradle to grave”.In this LCA, the ecological advantages associated with the transfer of a chemical synthesis from a macro-scale semi-continuous batch process to a continuous micro-scale setup were researched. The two-step synthesis of m-anisaldehyde from m-bromoanisole was taken as a model reaction. Because of its highly exothermic behavior, this synthesis can only be carried out under significant safety precautions and with a high cooling energy effort in conventional batch reaction equipment. A reaction temperature of T=223 and 193 K, respectively, was chosen. The application of micro-structured devices allows a continuous isothermal reaction setup at . We analyzed two scales of producing m-anisaldehyde, the laboratory scale and the industrial scale, in order to get detailed information about possible ecological advantages of microreaction technology. Within the term “laboratory scale” a synthesis of 10 kg m-anisaldehyde under laboratory conditions was defined. Two Cytos^®-Lab-System modules were chosen as reaction devices in the case of the microreaction mode. Otherwise, the synthesis of 1 t m-anisaldehyde under real production conditions is determined as “industrial scale” production. The production in the Cytos^®-Pilot-System with 11 microreactors in parallel for each synthesis step serves as the basis of comparison with a conventional macro-scale batch production. The product mass flow of 0.06 kg/h per microreactor was the same on both scales.The results of the LCA clearly point out that the application of microreaction technology can lead to significant reductions of the environmental impact resulting from chemical production processes.