Analysis of forced periodic operation of chemical reactors considering methanol synthesis as an example

该项目为严格评估化学反应器的强制周期性操作提供了新的方法和工具。在第一阶段，重点是在无梯度等温反应器中使用工业Cu/ZnO/Al 2 O3催化剂由H2/CO2/CO合成甲醇。从理论上证明了强制周期运行可以显著提高反应器的性能。在第二阶段，我们将对实验结果进行验证，并将理论和实验分析扩展到实际应用中经常使用的非等温固定床反应器。热效应引入了额外的约束，但也为强制周期性反应堆操作引入了额外的自由度。除了甲醇合成，还将与SPP的专家合作研究甲烷化的强制周期性操作。为了实现我们的目标，该项目将贝尔格莱德大学的Nikolić-Paunić博士在非线性频率响应分析方面的深厚专业知识与严格的数学优化和在马格德堡和弗赖堡进行的仔细实验验证相结合。Nikolić-Paunić博士在第一阶段为该项目做出了重大贡献，并将取代即将退休的Petkovska教授。在我们的方法中，非线性频率分析用于快速评估不同输入变量组合的可能改进。它还为进一步优化提供了良好的初始猜测。由于非线性频率响应分析的基本简化假设，结果必须在第二步中使用严格的数学优化来进一步细化，以便为计划的实验验证提供合适的条件。特别是，更详细的动力学模型，额外的自由度和实验设置和操作条件所产生的约束，可以严格考虑。为此，将与SPP合作伙伴合作，进一步完善在第一阶段开发的动力学模型，因为SPP在多相催化方面提供了所需的专门知识。此外，非线性频率分析、参数识别和数值优化的方法需要大大扩展，以处理与常微分方程相比，由固定床反应器建模产生的偏微分方程系统。在第一个供资期用于描述无梯度反应器。最后计划的强制定期运行的实验演示将用于验证方法和模型，并评估这种新的动态反应堆运行概念的适用性和潜力。

The proposed project provides new methods and tools for a rigorous evaluation of forced periodic operation of chemical reactors. In the first period, focus was on methanol synthesis from H2/CO2/CO using an industrial Cu/ZnO/Al2O3 catalyst in a gradientless isothermal reactor. It was shown theoretically that reactor performance can be improved significantly through forced periodic operation. In the second period results will be validated experimentally and the theoretical and experimental analysis will be extended to non-isothermal fixed bed reactors, which are often applied in practice. Heat effects introduce additional constraints but also introduce additional degrees of freedom for forced periodic reactor operation. Besides methanol synthesis also forced periodic operation of methanation will be studied in cooperation with the experts in the SPP.To achieve our goals, the project combines the profound expertise of Dr. Nikolić-Paunić from Belgrade University in nonlinear frequency response analysis with rigorous mathematical optimization and careful experimental validation to be done in Magdeburg and Freiburg. Dr. Nikolić-Paunić has contributed significantly to the project in the first period and will replace Prof. Petkovska, who will retire.In our approach, nonlinear frequency analysis is used for a quick evaluation of the possible improvement for different combinations of input variables. It also provides good initial guess for further optimization. Due to the underlying simplifying assumptions of the nonlinear frequency response analysis, results have to be further refined in a second step using rigorous mathematical optimization to provide suitable conditions for the planned experimental validation. In particular, more detailed kinetic models, additional degrees of freedom and constraints arising from the experimental setup and the operating conditions can be taken rigorously into account. For this purpose the kinetic model developed in the first period will be further refined in cooperation with SPP partners which provide the required expertise in heterogeneous catalysis.In addition, the methodologies for nonlinear frequency analysis, parameter identification and numerical optimization need to be extended significantly to handle systems of partial differential equations arising from the modeling of fixed bed reactors compared to ordinary differential equations, which are used in the first funding period for the description of a gradient free reactor. The finally planned experimental demonstration of forced periodic operation will serve to validate the methods and models and to evaluate the applicability and the potential of this new dynamic reactor operation concept.