Reactive extraction columns - particle population balances and scale up

颗粒群平衡是当今建模多分散体系的基石，这些体系出现在许多工程应用中，如结晶、造粒、乳液聚合、沸腾床和微生物系统。高颗粒密度的液体流动现象是出了名的复杂，难以测量和预测，当涉及化学反应时，数值计算更加复杂。与物理萃取相比，反应萃取在世界范围内是占主导地位的应用(见Int.索尔夫。提取会议http://www.solventextract.org/index.html).然而，混合-定居者在这一领域占据主导地位。柱在经济上更具吸引力的使用因其更复杂的设计而受到阻碍。在早期设计阶段(上市时间)，拥有可靠的模型和模拟工具是至关重要的。因此，通过人口平衡来考虑颗粒物的性质是一个中心点。在这方面，我们希望在较高的通用水平上验证我们的柱放大和设计方法，因此它应该在一种特定类型的搅拌(Kühni)分别上获得批准。脉冲柱(筛板)，它们在内部流动结构上有很大的互补性。工作计划将验证我们的工作假设，即对于任何塔类型，甚至对于复杂的反应体系(例如，使用欧洲化学工程联合会(EFCE)推荐的化学反应体系ZnSO4/D2EHPA/正庚烷作为反应测试系统)，可以从台架和微型工厂数据扩大规模。作为优势，我们从以前的工作中获得了手头的所有设备(需要一些调整)，并拥有高度自动化的数据采集，这使得我们能够承担拟议的紧凑时间表程序。小于DN200的柱的流动行为通过文献中的关联得到了适当的表征。然而，对于更大的柱，几何比不再是理想的，相关性不再有效，因此不确定放大。在这方面，借助CFD方法(CFD和PPB的耦合)，应导出空间分辨信息，作为深入理解的基础(基于PC的导出返混系数等)。以及解决任何新隔室几何形状中的局部现象(死区、搅拌器排放流)。该项目的成果对于任何几何形状的分散反应流体的工业设备的设计和放大都是非常重要的。发展的方法论是在一个经验主导的领域获得更多洞察和理解的基础。从标准化的实验室规模和小型工厂实验开始，计算机辅助放大可以减少时间和成本，昂贵的实验，并在其他难以探索的领域给出结果。

Particle population balances form nowadays the cornerstone for modeling poly-dispersed systems arising in many engineering applications such as crystallization, granulation, emulsion polymerization, fluidized beds and microbial systems. The phenomenon of liquid flows with high particle densities is notorious complex, difficult to measure and predict and numerically more complex when chemical reactions are involved. Reactive extraction is in comparison to physical extraction the world-wide the dominant application (see Int. Solv. Extraction Conferences http://www.solventextract.org/index.html). However, mixer-settlers dominate the field. The economically more attractive use of columns is hindered by their more sophisticated design. In an early design phase (time to market) it is essential to have reliable models and simulation tools. Therefore, the consideration of the particulate nature via population balances is a central point. In that respect we want to validate our column scale-up and design methodology at a high generic level, so it should be approved on one certain type of a stirred (Kühni) resp. pulsed column (sieve tray), which are quite complementary in their internal flow structure. The working program shall validate our working hypothesis, that a scale up from bench and miniplant data is possible for any column type and even for complex reactive systems (e.g. with the chemically reactive system ZnSO4/D2EHPA/n-heptane, recommended by the European Federation of Chemical Engineering (EFCE) as reactive test system). As advantage, we have from previous works all equipment at hand (needs some adaptions) and have a highly automated data acquisition, which allows to undertake the proposed tight scheduled program.The flow behavior for columns smaller than DN200 is properly characterized with correlations from literature. However, with bigger columns the geometry ratios are no longer idem, the correlations no longer valid and scale up is thus uncertain. In that respect with the help of CFD methods (coupling of CFD & PPB) spatial resolved information should be derived as basis for a profound understanding (PC-based derived backmixing coefficients etc.) and resolution of local phenomena (dead zones, stirrer discharge flow) in any new compartment geometry.The outcome of this project is of utmost importance for the design and scale-up of industrial equipment involving dispersed reactive fluids in any geometry. The developed methodology serves as basis for gaining more insight and understanding in an empirically dominated field. Starting with standardized bench scale and miniplant experiments a computer aided scale up can reduce time and cost expensive experimentation and give results in domains otherwise difficult to explore.