Efficient and Modular Methane Upgrading to Liquid Aromatics by Coupling Dehydroaromatization with Reactive Hydrogen Separation

拟议的研究项目旨在开发一种将甲烷转化为液体芳香族化合物的有效工艺。将甲烷有效转化为液态碳氢化合物（如芳烃）一直是石油行业长期存在的问题，由于页岩气技术的进步和天然气原料的丰富，人们对甲烷的高效转化产生了新的兴趣。通过催化脱氢芳构化（DHA）将甲烷直接转化为芳烃的提议与可以利用分布式原料的模块化制造技术兼容。然而，DHA对甲烷的转化和芳香族化合物的产率受到了严重的热力学限制。PI建议将DHA与能够从碳氢化合物中反应分离氢的化学环结合起来，以绕过这一热力学限制，并大幅提高芳烃产量。甲烷在DHA中的低转化率不能仅仅通过开发更好的催化剂来提高对芳烃的选择性来解决，因为固有的热力学限制降低了总体转化率。通过与氧化还原化学回路配对，可以实现氢（DHA的产物）的反应性分离，从而减轻了热力学限制。该项目将通过四个步骤将DHA与化学循环结合起来：1)甲烷DHA， 2) DHA排出物中的氢选择性氧化，3)除水，4)氢再生。氢气的去除和再生将在单独的反应器中进行。首先将论证拟议循环中每个步骤的可行性，并对操作条件和材料进行优化，以最大限度地提高每个步骤的效率。建立了一个实验室规模的半自动化装置，以评估该策略在多个循环中的芳烃收率。设计、合成了具有核壳结构的固体氧化还原对，并对其在含芳烃原料中的选择性氢氧化进行了评价。除了培训研究生外，该项目还包括将研究成果纳入化学工程课程和旨在教育公众有关气候变化、可持续性和可再生能源技术最新进展的推广活动。将开发一个基于移动设备的软件平台，与目标学生群体建立联系，提供教育资源，促进与研究相关的职业选择，特别强调吸引和留住来自科学、技术、工程和数学（STEM）项目中代表性不足群体的学生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The proposed research project aims to develop an efficient process for converting methane to liquid aromatic compounds. Efficient conversion of methane to liquid hydrocarbons, such as aromatics, has been a long-standing problem in the petroleum industry with renewed interest due to recent advances in shale gas technologies and the abundance of natural gas feedstocks. The proposed direct conversion of methane to aromatics via catalytic dehydroaromatization (DHA) is compatible with modular manufacturing technologies that can take advantage of distributed feedstocks. However, the conversion of methane and the yield of aromatic compounds via DHA are severely thermodynamically limited. The PI proposes to combine DHA with a chemical loop capable of reactively separating hydrogen from hydrocarbons to circumvent this thermodynamic limitation and substantially increase the aromatics yield.The low conversion of methane in DHA cannot be solely addressed by the development of better catalysts that improve selectivity to aromatics, due to the inherent thermodynamic limitations that lower the overall conversion. By pairing with a redox chemical loop, reactive separation of hydrogen (a product from DHA) can be achieved, which alleviates the thermodynamic limitation. The project will combine DHA with a chemical loop in four steps: 1) DHA of methane, 2) selective oxidation of hydrogen from the DHA effluent, 3) water removal, and 4) regeneration of hydrogen. The removal and regeneration of hydrogen will occur in separate reactors. The feasibility of each step in the proposed cycle will be demonstrated first and both the operating conditions and materials will be optimized to maximize the efficiency of each step. A laboratory-scale semi-automated setup will be constructed to evaluate the yield of aromatics with the proposed strategy in multiple cycles. Solid redox pairs with a core-shell structure will be designed, synthesized and evaluated for the selective hydrogen oxidation in aromatics-containing feeds. In addition to training graduate students, the project includes integration of research results into the chemical engineering curriculum and outreach activities aimed at educating the general public on climate change, sustainability and recent advances in renewable energy technologies. A mobile device based software platform will be developed to connect with targeted student groups, provide educational resources and promote research-related career options, with special emphasis on attracting and retaining students from underrepresented groups in science, technology, engineering and mathematics (STEM) programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.