Mass spectrometric investigation of chemical conversion processes in flow reactors

研究单位工作的主要目标是调查发动机作为灵活化学反应器的使用情况。在这里称为多联产的过程中，发动机应该同时提供更高价值的化学品、热量和机械功。计划中的工作是研究单位1993年GV1项目中开展的研究的继续。GV1侧重于研究化学转化过程的基本动力学过程。在该项目的第三阶段，调查的主要目标是评估臭氧作为添加剂对感兴趣的化学品形成的影响，因为预计臭氧已经在很低的浓度下激活了转化反应。在T=300-1200K和高压(1-20bar)的两种流动反应器中进行了不同停留时间的富燃混合气体的研究。用质谱仪和气相色谱分析了反应器出口的气体组成。所需的化学转化过程是所有可能用于储存化学能的反应，例如脱氢、水蒸气重整或C-C偶联反应，以及部分氧化。通过分析产品气体组成随工艺参数压力、温度或停留时间的变化，确定了导致感兴趣产品形成的条件。作为反应器温度或停留时间函数的浓度分布可作为1993年研究单元开发和测试“PolyMech”反应机理的验证数据。反应机制作为一种信息传递手段，将基础研究的结果应用于应用--发动机中的工作和化学品的联合生产。项目第三阶段的工作依赖于前两个项目阶段已经成功实施的方法和已建立的合作。在第三阶段项目中，除了甲烷和天然气外，还将使用生物燃料和添加剂(沼气、乙醇、甲醇和乙二醇醚)，以扩大可获得的产品范围。然而，最重要的科学问题是，臭氧作为添加剂的使用如何影响化学转化过程。臭氧已经在低温下分解成活性自由基，并可以通过这种方式激活转化反应。由于与其他添加剂不同，它不会与燃料竞争可用氧，因此它不会限制燃料的转化率。在这些观察的基础上，将研究臭氧在多大程度上可以用来提高产品产量和含氧和非含氧产品的选择性。作为研究的结果，对臭氧的反应机理有了一个基本的动力学理解。

The main objective of work in the research unit is to investigate the use of engines as flexible chemical reactors. In processes, referred to here as polygeneration, the engines should simultaneously provide higher-value chemicals, heat, and mechanical work. The planned work is the continuation of research performed in the project GV1 of the research unit FOR 1993.GV1 focusses on the investigation of the fundamental kinetic processes underlying the chemical conversion processes. In the third phase of the project, the main objective of the investigations is to assess the influence of ozone as additive on the formation of interesting chemicals because it is expected that ozone already activates the conversion reactions at very low concentrations. Fuel-rich gas mixtures are investigated in two types of flow reactors at temperatures between T = 300 – 1200 K, and high pressure (1 – 20 bar) for different residence times. The gas composition at the outlet of the reactor is analyzed by mass spectrometry and gas chromatography. Desired chemical conversion processes are all reactions that can potentially be used to store chemical energy, e.g. dehydrogenations, steam reforming, or C-C-coupling reactions, and partial oxidations. Conditions that lead to the formation of interesting products are identified by analyzing the product gas composition as function of the process parameters pressure, temperature or the residence time. Concentration profiles as function of reactor temperature or residence time serve as validation data for the development and testing of the “PolyMech” reaction mechanism developed in the research unit 1993. The reaction mechanism serves as a means of information transfer to apply results from the fundamental investigations to the application – the co-production of work and chemicals in the motor.The work in the third phase of the project relies on the methods already successfully implemented in the first two project phases and established collaborations. In the third project phase, biogenic fuels and additives (biogas, ethanol, methanol and oxymethylene ethers) will be used in addition to methane and natural gas to expand the accessible spectrum of products. The most important scientific question is, however, how the use of ozone as additive affects the chemical conversion processes. Ozone decomposes already at low temperature into reactive radicals and can activate the conversion reactions in this way. Since, in contrast to other additives, it does not compete with the fuel for the available oxygen, it does not limit the conversions of the fuel. Based on these observations, it will be investigated to what extent ozone can be used to improve the product yields and the selectivities of oxygenated and non-oxygenated products. As a result of the investigations, a fundamental kinetic understanding of the reaction mechanisms of ozone is generated.