Temporally and spatially resolved non intrusive measurement of temperature and species concentration profiles during catalytic production of synthetic methane in open cell foam catalysts (CARS4KAT)

能源系统向清洁、可靠和经济供应的转变需要长期和大规模的储能解决方案，同时需要脱碳。应对这一挑战的一个有希望的方法是Power-to-X技术，该技术嵌入了国家氢战略。再生氢（H2）和选择性分离二氧化碳（CO2）催化生产合成甲烷（CH4），一方面是大规模和长期储存能力的基础，另一方面是一个有吸引力的部门耦合工具。目前，在技术相关的甲烷化系统中，大多采用镍基本体催化剂的固定床反应器。由于强烈的放热反应和挥发性氢供应，这些反应器在动力学不利的条件下运行或需要复杂的散热系统。一个有希望的替代方案，以加强传热和传质是高多孔，网状开孔泡沫催化剂载体。结合新型和坚固的涂层，改进的催化剂是可制造的。对局部反应以及传热传质机理的基本了解是催化剂设计和工艺强化的基础，但由于缺乏局部验证数据而经常缺失。因此，迫切需要一种非侵入性的、空间和时间分辨的催化剂宏观结构内部的温度和物质浓度分布。本文开发了一种新的适用于该应用的相干反斯托克斯拉曼光谱方法，并应用于测量动态条件下催化开孔泡沫内的同步和非侵入性温度和多物种浓度分布（H2, CO2, CH4， CO, H2O, N2）。启动和冷却阶段是特别有趣的。目标是专门开发的二氧化钛支撑和镍基开孔泡沫甲烷化催化剂，适用于大规模的Power-to-X应用。宏观电池结构中的局部热点分析、特征温度曲线的形成、局部工艺参数（如co2转化率和ch4产率）的确定以及反混合区和传质限制的确定是制造效率更高的催化剂所必需的。此外，在spp2080中开发的其他结构化催化剂也可以进行研究。此外，局部参数将应用于现有的传热传质模型（由Sundmacher教授支持）或固定床反应器和催化剂的动力学模型。这种对局部反应以及传热传质机制的基本理解将是建立用于大规模二氧化碳甲烷化的开孔泡沫催化剂的实质性和必要的一步。双方在激光光谱学（TTS）和催化系统（LEUVT）领域的综合能力是项目成功的关键基础。

Transformation of energy systems towards a clean, reliable and economical supply demands long-term and large-scale energy storage solutions with concurrent decarbonization. A promising approach for this challenge are Power-to-X technologies which are imbedded within the national hydrogen strategy. The catalytic production of synthetic methane (CH4) from regenerative hydrogen (H2) and selectively separated carbon dioxide (CO2) is on the one hand basis for the large-scale and long-term storage capacity and on the other hand an attractive tool for sector coupling. Today mostly fixed-bed reactors with nickel-based bulk catalysts are used in technical relevant methanation systems. Due to the strong exothermic reaction and the volatile hydrogen supply these reactors are operated at kinetically unfavorable conditions or require complex heat removal systems. A promising alternative to enhance heat and mass transfer are highly porous, net-shaped open-cell foam catalyst supports. In combination with novel and robust coatings, improved catalysts are manufacturable. Basic understanding of local reaction as well as heat and mass transfer mechanisms is fundamental for catalyst design and process intensification but is often missing due to absence of local validation data. Therefore, there is a strong need for non-invasive, spatial and temporal resolved temperature and species concentration profiles inside the macrostructure of the catalyst. Here a new and for this application adapted coherent anti-Stokes Raman spectroscopy approach is developed and applied to measure simultaneous and non-intrusive temperature and multispecies concentration profiles (H2, CO2, CH4, CO, H2O, N2) inside catalytic open cell foams under dynamic conditions. Start up and cool down phases are of special interest. The objective are specially developed, titania supported and nickel-based open cell foam methanation catalysts that are suitable for large-scale Power-to-X applications. The local analysis of hot spots in the macroscopic cell structure, the formation of characteristic temperature profiles, the determination of local process parameters such as CO2-conversion and CH4-yield and the identification of back mixing zones and mass transfer limitations is necessary to manufacture catalysts with increased efficiency. Furthermore, other structured catalysts developed within the SPP 2080 can be investigated. Additionally, local parameters will be applied to existing models for heat and mass transfer (supported by Prof. Sundmacher) or kinetic models of fixed bed reactors and catalysts.This basic understanding of local reaction as well as heat and mass transfer mechanisms will be a substantial and necessary step towards the establishment of open-cell foam catalysts for the large-scale methanation of CO2. The combined competence of both project partners in the field of laser-based spectroscopy (TTS) and in the field of catalytic systems (LEUVT) is the crucial basis for the success.