Innovative Ammonia Generation: Harnessing Earth’s Natural Resources
Researchers are turning to the Earth’s underground heat and natural geological processes to create ammonia for fertilizer, moving away from traditional methods that rely heavily on energy-intensive reactors.
A Game-Changer in Sustainable Fertilizer Production
Published in the journal Joule on January 21, this compelling proof-of-concept study demonstrates a method of producing ammonia by blending nitrogen-infused water with iron-rich rocks, all achieved without any external energy requirements or carbon dioxide emissions. This innovative approach has the potential to provide enough ammonia for a staggering 2.42 million years.
Inspiration from Nature’s Chemistry
The researchers drew inspiration from a unique geological occurrence recorded in the 1980s in Mali, West Africa. Residents found a well emitting hydrogen gas; subsequent studies revealed this was caused by natural chemical reactions occurring between rock and water deep beneath the surface.
“That moment was enlightening,” notes Iwnetim Abate, a lead researcher affiliated with MIT. “It suggested that we could utilize Earth as a natural factory—leveraging its inherent heat and pressure to create essential chemicals like ammonia more sustainably.”
The Energy Dilemma of Current Methods
Ammonia plays an integral role in fertilizer production but is currently produced through methods that consume approximately 2% of global energy resources and emit around 5,291 pounds of CO2 per ton of ammonia created—positioning it as one of the leading contributors to industrial CO2 pollution.
Pioneering Methods: The Earth Factory Concept
To explore their hypothesis regarding “Earth factories,” Abate’s team constructed a system that imitates subterranean conditions. They introduced synthetic iron-based minerals to nitrogen-saturated water which initiated an oxidation reaction within the rock leading to viable amounts of what they termed “geological ammonia.” Notably, this process did not require any external energy input and functioned effectively at ambient environmental conditions.
Field Applications with Real-World Rock Types
The next phase involved replacing synthetic minerals with olivine—a naturally occurring iron-rich stone—to enhance real-world application relevance. After optimizing their setup using copper catalysts while elevating temperatures to about 572°F (300°C), they successfully generated approximately 4 pounds (1.8 kg) of ammonia per ton (about 2204 lbs) of olivine over just over twenty hours—validating both efficiency and sustainability aspects of this technique.
A Global Approach With Local Resources
“These minerals are abundant worldwide—which means our approach can be adapted across diverse global settings,” indicates Abate, yet acknowledges further complexities must be addressed moving forward.
Tackling Challenges Ahead
This innovative concept aims not only at effective drilling into ore deposits but also addressing intricate interactions involving rock chemistry when exposed to gases under various pressures combined with injected nitrogen solutions. To advance these efforts, plans include pilot tests targeted for completion by mid-2026 via Addis Energy—a venture co-founded by Abate himself.
A Promising Economic Proposition
The prospects appear bright; producing geological ammonia is estimated at about $0.55 per kilogram compared favorably alongside traditional methods priced between $0.40–$0.80 per kilogram.”)
Meanwhile important implications exist regarding wastewater management opportunities linked directly through these new methodologies.
Yifan Gao points out:
“Excessive nitrogen discharged into wastewaters represents cost-bearing pollution today; however if integrated into our process we can transform it profitably—resulting rather symbiotically.” This dual integration could yield profits amounting up-to $3..82 surplus concerning each unit produced thus far referred before.”
