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

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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.