Advancements in Plasma-Based Nitrogen Fixation for Sustainable Fertilizer Production at High Pressures

Plasma-based nitrogen fixation has emerged as a promising and environmentally friendly alternative to conventional fossil fuel-based processes for fertilizer production. However, most experiments with plasma-based nitrogen fixation have been conducted at low pressure conditions, whereas industrial requirements often involve high pressures. In this pioneering study, we investigated the use of a microwave plasma for nitrogen fixation at high pressures, with varying feed gas flow rates and composition. Our findings revealed significant advancements in terms of NOx production, energy consumption, and selectivity. We observed a dramatic increase in the amount of NOx (NO + NO₂) produced as a function of increasing pressure, with the highest production rates achieved at the highest pressure of 2 bara. Notably, our results showed a record-low energy consumption for plasma-based nitrogen fixation at high pressures, indicating the potential for more energy-efficient processes. Moreover, we achieved an impressive selectivity of NO₂, which is a crucial component for the formation of nitrate-based fertilizers, known for their high efficiency in plant growth. Our study presents a novel approach of utilizing microwave plasma for nitrogen fixation at high pressures, which has not been extensively explored in previous research. The results suggest that plasma-based nitrogen fixation at high pressures has the potential to offer more sustainable and energy-efficient solutions for fertilizer production.