Ammonia Synthesis at Low Pressure.

Area of Science:

• Chemical Engineering
• Sustainable Chemistry

Background:

• Ammonia synthesis traditionally requires high pressures (Haber-Bosch process), limiting decentralized production.
• Renewable energy sources like wind are often geographically constrained ('stranded energy').

Purpose of the Study:

• To develop a low-pressure ammonia synthesis process powered by renewable energy.
• To overcome equilibrium limitations in ammonia synthesis using selective absorbents.

Main Methods:

• Nitrogen production via pressure swing absorption from air.
• Hydrogen production through water electrolysis.
• Ammonia synthesis at low pressure using a promoted catalyst and selective absorbent (alkaline metal halide).

Main Results:

• The process operates effectively at low pressures, driven by renewable energy.
• Selective ammonia absorption suppresses reverse reaction, removing equilibrium constraints.
• Reaction rate controlled by gas recycle, not kinetics or absorption.

Conclusions:

• The proposed absorption-enhanced ammonia synthesis is a promising alternative to the Haber-Bosch process for small-scale, localized production.
• This method enables the utilization of stranded wind energy for fertilizer manufacturing.