Energy-Efficient Small-Scale Ammonia Synthesis Process with Plasma-enabled Nitrogen Oxidation and Catalytic Reduction of Adsorbed NOx

Industrial ammonia production without CO2 emission and with low energy consumption is one of the technological grand challenges of this age. Current Haber-Bosch ammonia mass production processes work with a thermally activated iron catalyst needing high pressure. The need for large volumes of hydrogen gas and the continuous operation mode render electrification of Haber-Bosch plants difficult to achieve. Electrochemical solutions at low pressure and temperature are faced with the problematic inertness of the nitrogen molecule on electrodes. Direct reduction of N-2 to ammonia is only possible with very reactive chemicals such as lithium metal, the regeneration of which is energy intensive. Here, the attractiveness of an oxidative route for N-2 activation was presented. N-2 conversion to NOx in a plasma reactor followed by reduction with H-2 on a heterogeneous catalyst at low pressure could be an energy-efficient option for small-scale distributed ammonia production with renewable electricity and without intrinsic CO2 footprint.

Automated summary

Industrial ammonia production without CO2 emission and with low energy consumption is a major challenge. Current methods relying on thermally activated iron catalysts at high pressure and continuous operation mode are difficult to electrify. Electrochemical solutions face issues with the inertness of nitrogen molecules on electrodes. This study proposes an oxidative route for N-2 activation as an energy-efficient option for small-scale distributed ammonia production with renewable electricity and without intrinsic CO2 footprint.