Toward Green Liquid Nitrogen Fertilizer Synthesis: Plasma-Driven Nitrogen Oxidation and Partial Electrocatalytic...

Area of Science:

• Sustainable Agriculture
• Plasma Chemistry
• Catalysis

Background:

• Traditional ammonium nitrate (NH4NO3) fertilizer production is fossil fuel-intensive and environmentally damaging.
• Liquid fertilizers with precision irrigation offer enhanced efficiency and sustainability.
• There is a need for innovative, eco-friendly nitrogen fertilizer synthesis methods.

Purpose of the Study:

• To develop and evaluate an innovative air-to-NOx-to-NH4NO3 pathway for liquid nitrogen fertilizer synthesis.
• To optimize plasma reactor conditions for efficient NOx generation and subsequent reduction.
• To assess the impact of the synthesized liquid fertilizer on plant growth and its production cost.

Main Methods:

• Utilized an underwater multi-bubble plasma reactor powered by nanosecond pulses to generate aqueous NOx from air.
• Employed electrocatalysis for the partial reduction of NOx to ammonium nitrate (NH4NO3).
• Conducted plasma diagnostics and global plasma chemistry modeling to understand reaction mechanisms.

Main Results:

• Achieved a maximum NOx production rate of 786.5 mol h-1 with an air-like N2/O2 ratio.
• Identified short pulse rise/fall times as critical for enhancing NOx yield through synergistic discharge effects.
• Demonstrated significant plant growth improvements (stem length +91.26%, leaf length +54.72%) using the synthesized fertilizer.

Conclusions:

• The developed plasma-based process offers a sustainable route for liquid nitrogen fertilizer production.
• Optimized plasma parameters and electrocatalysis are key to efficient synthesis.
• Further cost reduction is possible through renewable energy integration, advancing sustainable agriculture.