Yield and selectivity analysis of a bubble flow using the example of toluene oxidation

气泡流的产率和选择性受反应网络动力学、质量输运、两相流的宏观混合以及气泡尾迹中的微观混合的影响。为了合理准确地预测反应泡群的产率和产品选择性，所涉及的机制的比率应该从单独的、独立的研究中确定。将实验或数值计算确定的参数输入到双流模型中，以确定在普遍条件下的产物形成。在这方面，委员会正在规划下列具体项目。i)在不受可能的质量传递限制影响的情况下，确定具有自由基链机制的技术合成的宏观动力学在正在进行的项目阶段，建立了一个在均匀条件下测量的动力学装置并成功运行。由于敏感性分析，测量结果的评价比较困难。需要进一步改进。开发的ki-netics将提供给AK Rzehak和AK Hlawitschka，用于以后的模型验证。一旦可用，AK Rinke的便携式拉曼探针将进行在线分析测试。验证预测气泡流产率和选择性的计算方法的实验该研究所有一个可在高压和高温下操作的气泡塔。在外围适应后，AK Schindler的反应性[Fe2(HPTB)Cl3]模型系统将被测量，然后是甲苯氧化。测量结果用于验证AK Rhezak和AK Hlawitschka的计算方法。混合过程对气泡尺度的影响对产物选择性的影响研究混合过程对气泡尺度的影响只能在宏观模拟中以与动力学“修正”相关的形式考虑。为了评估对产品选择性的影响，建立了一个简化模型。目的是研究在哪些条件下这些是必要的，并视情况而定，开发一种简化的计算方法，使混合物对气泡规模的影响能够集成到宏观计算中。我们正在与AK马歇尔合作，比较简化和详细的模拟。此外，已同意与AK Hampel / Kryk就方法进行密集交流。

Yield and selectivity of a bubbly flow are influenced by the kinetic of the reaction network, the mass transport, the macroscopic mixing of a two-phase flow as well as the microscopic mix-ing in the bubble wake. To predict yield and product selectivities in a reactive bubble swarm with reasonable accuracy the rates of the involved mechanisms should be determined from separate, independent studies. The parameter determined by experiments or numerical cal-culations are input to a two-flow model to determine the product formation under the prevailing conditions.Within that context the ICVT is planning the following particular projects.i) The determination of a macroscopic kinetics for a technical synthesis with a radical chain mechanism without influence of a possible mass transport limitationIn the ongoing project phase a kinetic apparatus for measurement under homogeneous con-ditions was set up and successfully operated. The evaluation of the measurement was diffi-cult due to the susceptible analysis. Further improvements are required. The developed ki-netics is to be made available to AK Rzehak and AK Hlawitschka for a later model validation. Once available, a portable Raman probe from the AK Rinke is to be tested for online analysis.ii) Experiments for validation of the calculation methodology for the prediction of yield and selectivity in a bubble flowThe institute has a bubble column available which is to be operated at elevated pressure and temperatures. After an adaptation of the periphery, the reactive [Fe2(HPTB)Cl3]-model sys-tem of the AK Schindler is to be measured, followed by the toluene oxidation. The measure-ments are used to validate the calculation methodology in AK Rhezak and AK Hlawitschka.iii) Studies on the influence of the mixture on the bubble scale on the product selectiv-itiesThe influence of the mixing processes on the bubble scale can only be considered in macro-scopic simulations in the form of correlations to the "corrections" of the kinetics. In order to assess the influence on product selectivity, a simplified model is to be developed. The aim is to investigate the conditions under which these are necessary and, as the case may be, to develop a simplified calculation methodology which allows the effects of the mixture on the bubble scale to be integrated into the macroscopic calculation. We are cooperating here with the AK Marschall to compare simplified and detailed simulations. Furthermore, an intensive exchange concerning the methodology with the AK Hampel / Kryk has been agreed to.