NSF Award
2328100
Ammonia is a critical component of nitrogen-based fertilizers, crucial in intensive agriculture to feed a continuously growing world population. Distributed, sustainable ammonia manufacturing, powered by renewable electricity and catalyzed by electroactive living microorganisms can have a tremendous impact on global energy consumption and related carbon emissions. This project addresses the critical societal need to enable decentralized ammonia manufacturing at the site of use such as a farm or municipality while simultaneously lowering carbon emissions. Such innovation will result in more equitable food production practices and infrastructure across the country, leading to sustainable agricultural practices across the globe. The outreach activities will broaden the societal impact of this work and train a future workforce aware of the impact of a sustainable chemical industry on the environment. On a K-12 level, this project will create new activities illustrating the potential of merging biology and electrochemistry for the sustainable production of fuels and energy. On a community college level, this project will launch a networking event, connecting students with innovative startups focusing on sustainability and circularity. On an undergraduate and graduate students level, this project will integrate new material on environmental electrochemistry in environmental engineering courses.<br/><br/>Current ammonia manufacturing is dominated by the carbon and energy intensive Haber-Bosch process, which was responsible for the emission of 600 Mt of CO2 and the consumption of 2% of the global energy produced in 2021. This future manufacturing seed grant will support fundamental research on convergent electrochemistry and metabolic engineering approaches to enable carbon-neutral production of ammonia, merging the productivity and efficiency of electrochemical synthesis with the exquisite selectivity and low cost of ammonia generation by nitrogen-fixing bacteria. This novel approach is based on a looped zero-gap electrochemical cell, coupling ammonia production from bacteria with abiotic carbon dioxide reduction to organic acids at the cathode. On the electrochemistry side, the project will (i) optimize the electron transport chain and improve nitrogenase activity and selectivity at the anode and (ii) maximize carbon dioxide reduction selectivity at the cathode. On the metabolic engineering side, the research will (a) manipulate metabolic and regulatory pathways to increase ammonia productivity and (b) enhance ammonia excretion. The successful outcome of this approach will be demonstrated by developing and testing a bench-scale, high-fidelity reactor for continuous production of ammonia at commercially relevant conditions that can be further scaled up to be implemented as an operating unit on an individual farm.<br/><br/>This Future Manufacturing project is jointly funded by the Division of Molecular and Cellular Biosciences in the Directorate for Biological Sciences, the Division of Chemical, Bioengineering, Environmental, and Transport Systems in the Directorate for Engineering, and the Division of Chemistry in the Directorate of Mathematical and Physical Sciences.<br/><br/>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.
