Complex Gas-Liquid Reactions with Mass Transfer in Coiled Flow Inverters

盘管换流器中复杂的气液反应和传质

• 批准号: 401436608
• 负责人: Professor Dr.-Ing. Norbert Kockmann
• 金额: --
• 依托单位: Lehrstuhl III: Angewandte Mathematik und Numerik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/401436608?language=en
• 关键词: Complex; Gas; Liquid; Reactions; Mass

Taylor bubble flow in capillaries is often used in chemical reaction technology. Due to complex fluid dynamics, it is only partly understood regarding mass transfer and selectivity of complex chemical reactions. Particularly in helical capillaries, the additional Dean flow complicates the situation, but improves radial mass transfer. For this purpose, an experimental system consisting of perfluorinated ethylene-propylene capillaries (FEP with the same refractive index as water or acetonitrile) with an internal diameter of 0.5 to 6 mm is built and investigated with gas-liquid reactions. The oxidation of leuco indigocarmine with a two-step color change as a consecutive reaction and glucose oxidase with color change parallel to sulfite oxidation are investigated. For these systems the diffusion coefficients and kinetic parameters are determined in a separate test facility. Bubble formation and bubble flow can be optically observed in a straight, vertical capillary with an internal diameter up to 6 mm as a reference case. In the helical capillary, Taylor-Dean flow is investigated with mixing, mass transfer, and complex chemical reactions. The Taylor-Dean flow profile can be entirely characterized, while different reactions with their typical time scales can also be optically examined in the capillaries with different diameters. In parallel, complex transport processes are numerically simulated with FeatFlow CFD Software. Additional 90° deflections between individual coils (Coiled Flow Inverter CFI) improve mixing by shifting the regions of the Taylor-Dean vortices. Dimensionless numbers as well as segregation index or exposure level are used for the analytical description of the mixing process of complex reactions. The numerical simulation of the complex Taylor-Dean flow requires a complete 3D simulation of the flow and the concentration field without and with chemical reactions. The numerical grid generation and treatment of the interface imposes high demands on the numerical tools. The adjustment of the kinetics of parallel and consecutive reactions allows for determining the local selectivity to the target molecule, which in the experiment causes a color change of the solution. As associated partner in the priority program further chemical reactions are tested in the CFI setup. In the course of the project further measurement techniques will be available with X-ray tomography, Raman-spectroscopy, and high-speed camera with macro lens.

毛细管中的泰勒泡状流常用于化学反应技术中。由于复杂的流体动力学，对于复杂化学反应的传质和选择性只有部分了解。特别是在螺旋毛细管中，额外的迪恩流使情况复杂化，但改善了径向传质。为此，建立了由内径为0.5 ~ 6 mm的全氟乙烯-丙烯毛细管（与水或乙腈具有相同折射率的FEP）组成的实验系统，并对气液反应进行了研究。研究了无色靛胭脂红氧化的两步连续变色反应和葡萄糖氧化酶氧化亚硫酸盐的平行变色反应。对于这些系统，扩散系数和动力学参数在单独的测试设备中确定。气泡形成和气泡流动可以在内径高达6 mm的直的垂直毛细管中进行光学观察。在螺旋毛细管中，泰勒-迪恩流的混合，传质和复杂的化学反应进行了研究。Taylor-Dean流动曲线可以完全表征，而具有其典型时间尺度的不同反应也可以在具有不同直径的毛细管中进行光学检查。并行地，复杂的输运过程用CFD软件进行了数值模拟。单个线圈之间的额外90°偏转（螺旋流逆变器CFI）通过移动泰勒-迪恩涡流区域来改善混合。无偏数和分离指数或暴露水平用于复杂反应混合过程的分析描述。复杂Taylor-Dean流的数值模拟需要对无化学反应和有化学反应的流动和浓度场进行完整的3D模拟。数值网格的生成和界面的处理对数值工具提出了很高的要求。平行和连续反应的动力学的调整允许确定对靶分子的局部选择性，其在实验中引起溶液的颜色变化。作为优先计划的相关合作伙伴，在CFI装置中测试了进一步的化学反应。在项目过程中，将通过X射线断层扫描、拉曼光谱和带微距透镜的高速相机提供进一步的测量技术。