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Title: Plasma Catalysis Modular Process for Ammonia Production

Technical Report ·
OSTI ID:1873619

In this project, Advanced Energy Materials LLC (ADEM) proposed to apply the plasma catalysis “PlasCatTM” process for ammonia production and demonstrate the process at near or slightly above atmospheric pressures. The plasma analysis approach has the potential for a transformational impact on gas processing for chemical/fuel production using renewables. Distributed and modular production of ammonia is of choice for decentralized production for energy security, and monetization of stranded gas. Currently, ammonia is produced worldwide using the Haber-Bosch process consuming about 1-2% of the world’s energy production. Haber-Bosch process operates at high pressures (>150 bar). Miniaturization of these plants to a modular scale will not be energy cost-efficient. ADEM’s PlasCatTM process uses highly energetic electrons and reactive species (e.g., radicals, excited atoms, molecules, and ions) on specially designed catalysts to enhance reaction kinetics and enable thermodynamically unfavorable reactions to proceed under ambient conditions. The use of plasma helps in the activation and dissociation of the N2 molecule, which is the rate-determining step in ammonia synthesis. The dissociated N atoms readily react on the catalyst surface with hydrogen forming ammonia. The plasma energy can also selectively heat the reactant gas mixture and the catalyst makes the process energy efficient. The major goal of the project is to develop a scalable plasma catalysis technology for modular-sized mini plants to produce ammonia at the targeted energy consumption. In this Phase I project, ADEM employed two types of atmospheric pressure plasma discharge reactors for its PlasCatTM process: microwave (MW) plasma torch and dielectric barrier discharge (DBD). Experiments involving plasma discharge and its proprietary catalysts have demonstrated synergy between plasma excitation and catalyst effect. In Phase I, ADEM developed and screened several catalyst materials based on nanowire/nanotube materials: iron nanotubes; titania, zinc oxide, and alumina nanowires alloyed with various elements such as iron, copper, nickel, and gallium; lithium aluminate/lithium titanate nanowires and several metals supported on titania nanowires. Of various catalysts tested, iron alloyed into titania nanowires; iron nanotube, and lithium aluminate nanowires performed with the highest activity toward ammonia production in both MW plasma and DBD reactors. Phase I effort also investigated different process chemistries involving argon, carbon dioxide, oxygen and steam along with nitrogen and hydrogen. The results showed ammonia concentration in outlet gas as high as 10% corresponding to 1.2 moles per hour per gram of catalyst in MW PlasCatTM process at 350 W power. Results also indicate nitrogen with steam and small amounts of hydrogen could yield similar range production rates. In the case of the DBD reactor, the results suggest a production rate of up to 5 mmol per hour per gram catalyst. However, the use of ammonia absorbent along with catalyst improved the production rate by an order of magnitude. The results with MW plasma torch and catalyst suggest technical feasibility for ammonia production at atmospheric pressure. The economic and life cycle analysis of ammonia production suggests economical production at 100 Kg/day or higher scale and reduced CO2 emissions (0.2-0.4 KgCO2/KgNH3) compared to the traditional H-B process at 1.8 KgCO2/KgNH3. The modular reactor system can be used at locations of fertilizer manufacturers, energy storage plants and chemicals production plants. This project will also strengthen the fundamental plasma science knowledge and turn it into new applications.

Research Organization:
Advanced Energy Materials LLC
Sponsoring Organization:
USDOE Office of Science (SC), Engineering & Technology. Office of Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) Programs
DOE Contract Number:
SC0021691
OSTI ID:
1873619
Type / Phase:
SBIR (Phase I)
Report Number(s):
DOE-AmmoniaPlasmacatalysis-2022-Final
Country of Publication:
United States
Language:
English