Chemical Looping Beyond Combustion: Syngas Production From Methane in a Periodically Operated Fixed-Bed Reactor

周期性固定床反应器是一种新兴的催化反应器，在能源和环境方面的应用越来越广泛。本项目旨在展示化学环的应用，这是一种新兴的燃烧技术，在定期运行的固定床反应器配置中，将甲烷部分氧化为合成气。由此产生的工艺具有显著的实际优势（通过避免甲烷和氧气之间的直接接触，减轻了甲烷部分氧化的安全问题，并且允许直接利用空气而不需要用氮稀释合成气），同时允许在定期固定床反应器中研究耦合吸热/放热气固反应的动力学。项目团队将进一步将化学循环原理扩展到一个完全多功能的反应器设计中，通过整合产品流的脱硫，从而形成一个强大的、高度可扩展的、高效的合成气过程。该方法建立在材料合成、反应堆设计和实验以及反应堆建模的基础上，具体包括以下步骤：-设计和建造一个固定床反应堆，具有高分辨率的原位动力学和时空动力学测量；-作为氧载体和部分氧化催化剂的高性能纳米结构材料的合成、表征和评价；-详细的反应器实验，包括反应器动力学和工艺效率的关键运行参数（共流和逆流流模式，周期等）的评估；-集成s捕获和分离，和-反应堆建模和详细的反应堆仿真。总的来说，本研究的主要目标是：(1)通过实验和反应器建模的结合，提高我们对热集成（特别是气固反应）定期运行固定床反应器动力学的理解；(2)展示化学环（CL）在燃烧之外的巨大潜力（包括综合污染物分离），并进一步确立固定床CL工艺的优势；(3)强调最先进的纳米材料作为“推动者”的令人兴奋的可能性。先进的反应堆工程概念。该项目将提高我们对固定床反应器周期性运行的认识和当前的理解，特别是对于气固反应，这一领域的重要性远远超出了化学环。它将进一步强调新兴纳米材料在实现先进反应堆概念方面的推动作用。最后，它将有助于进一步建立和扩大？化学循环?通过演示同时使用化学环进行部分氧化反应并结合污染物去除的应用，并通过彻底的实验和基于模型的分析，为将概念扩展到广泛的新应用奠定了基础。更广泛的影响：在美国已探明的国内天然气储量呈爆炸式增长之际，展示一种新型、紧凑、高效、安全的天然气利用反应堆概念可能会产生广泛的影响。此外，这项技术还可以利用小规模的分布式来源，如垃圾填埋气和农业废气，从而产生切实的环境效益。该项目将有助于研究生和本科生的教育，并涉及到来自代表性不足群体的高中生。最后，通过合作、出版物和会议贡献积极分发已开发的方法和工具将有助于促进伙伴关系，并使整个科学界获得进展。

Intellectual Merit: Periodically operated fixed-bed reactors are an emerging type of catalytic reactors with increasing application in energy and environmental applications. The present project aims to demonstrate the application of chemical looping, an emerging combustion technology, to the partial oxidation of methane to synthesis gas in a periodically operated fixed-bed reactor configuration. The resulting process has significant practical advantages (alleviating safety concerns in methane partial oxidation by avoiding direct contact between methane and oxygen, and allowing direct utilization of air without diluting the syngas with nitrogen), and will at the same time allow the investigation of the dynamics of coupled endothermal/exothermal gas-solid reactions in periodic fixed-bed reactors. The project team will furthermore extend the chemical looping principle onto a fully multifunctional reactor design by integrating desulfurization of the product stream, resulting in a strongly intensified, highly scalable, and efficient syngas process.The approach builds on a combination of materials synthesis, reactor design and experimentation, and reactor modeling, and involves specifically the following steps:- Design and construction of a fixed-bed reactor with high-resolution in-situ measurement of kinetics and spatio-temporal reactor dynamics;- Synthesis, characterization, and evaluation of high-performance nanostructured materials as oxygen carriers and partial oxidation catalysts;- Detailed reactor experimentation, including evaluation of key reactor operating parameters (co- and counter-current flow pattern, periodicity, etc.) on reactor dynamics and process efficiency;- Integration of S-capture and separation, and- Reactor modeling and detailed reactor simulation.Overall, the main objectives of this research are (1) to advance our understanding of the dynamics of periodically operated fixed-bed reactors with heat-integration (specifically for gas-solid reactions) through a combination of experiments and reactor modeling; (2) to demonstrate the great potential of chemical looping (CL) beyond combustion (including integrated contaminant separation) and further establish the advantages of fixed-bed CL processes; and (3) to highlight the exciting possibilities of state-of-the-art nanomaterials as ?enablers? for advanced reactor engineering concepts .The project will advance our knowledge and current understanding of periodically operated of fixed-bed reactors, specifically for gas-solid reactions, an area with importance well beyond chemical looping. It will furthermore highlight the enabling role that emerging nanomaterials can play in the realization of advanced reactor concepts. Finally, it will help to further establish and broaden ?chemical looping? applications by demonstrating the simultaneous use of chemical looping for a partial oxidation reaction combined with contaminants removal, and, through thorough experimental and model based analysis, lay the groundwork for extending the concept onto a broad range of new applications.Broader Impact: Demonstration of a novel, compact, efficient, and safe reactor concept for natural gas utilization could have broad impact at a time where proven domestic gas reserves in the US are seeing explosive growth. Furthermore, this technology could enable the use of small-scale distributed sources, such as landfill gas and agricultural waste gas, resulting in tangible environmental benefits. The project will contribute to the education of graduate and undergraduate students, and involve outreach to high school students from underrepresented groups. Finally, active distribution of the developed methodologies and tools through collaborations, publications and conference contributions will help to foster partnerships and make the advances available to the scientific community at large.