(698a) Ambient Pressure Carbon-Neutral Ammonia Generation Via a Cyclic Microwave Plasma Process
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Nitrogen Chemistry II: Nitrogen Thermochemistry
Tuesday, November 7, 2023 - 3:30pm to 3:55pm
Plasma-enhanced catalysis can overcome limitations in traditional heterogeneous catalysis by the activation of stable species, surface medication, and generation of vibrationally active species 1,2. Plasma catalytic technology combined with new catalyst development may allow low pressure alternatives to the Haber-Bosch (HB) process 3. Ammonia as currently synthesized represents 1-2% of global energy use and 2.5% of global CO2 emissions 4. The United Nations 1.5 °C global temperature rise goal requires deep emissions cuts which require changes in current ammonia production to reduce CO2 emissions. Plasma-catalytic processes offer the possible benefits of being small-scale, modular, and part of a renewable energy grid for ammonia synthesis 5.
A novel reactor methodology for chemical looping ammonia synthesis processes using microwave plasma pre-activation of the stable dinitrogen molecule was developed. Metallic iron (Fe) catalysts were used in the atmospheric plasma-enhanced synthesis of ammonia. Rates of up to 420.9 μmolmin-1g-1 were observed under mild nitriding conditions. Reaction studies, kinetic modeling, and plasma characterization were performed for this system.
References:
(1) Bogaerts, A.; Neyts, E. C. Plasma Technology: An Emerging Technology for Energy Storage. ACS Energy Lett. 2018, 3 (4), 1013–1027. https://doi.org/10.1021/acsenergylett.8b00184.
(2) Mehta, P.; Barboun, P.; Herrera, F. A.; Kim, J.; Rumbach, P.; Go, D. B.; Hicks, J. C.; Schneider, W. F. Overcoming Ammonia Synthesis Scaling Relations with Plasma-Enabled Catalysis. Nat Catal 2018, 1 (4), 269–275. https://doi.org/10.1038/s41929-018-0045-1.
(3) Rouwenhorst, K. H. R.; Burbach, H. G. B.; Vogel, D. W.; Núñez PaulÃ, J.; Geerdink, B.; Lefferts, L. Plasma-Catalytic Ammonia Synthesis beyond Thermal Equilibrium on Ru-Based Catalysts in Non-Thermal Plasma. Catal. Sci. Technol. 2021, 10.1039.D0CY02189J. https://doi.org/10.1039/D0CY02189J.
(4) Pfromm, P. H. Towards Sustainable Agriculture: Fossil-Free Ammonia. Journal of Renewable and Sustainable Energy 2017, 9 (3), 034702. https://doi.org/10.1063/1.4985090.
(5) Winter, L. R.; Chen, J. G. N2 Fixation by Plasma-Activated Processes. Joule 2021, 5 (2), 300–315. https://doi.org/10.1016/j.joule.2020.11.009.