Americans have learned to produce “green” ammonia by simply pumping wastewater underground

Ammonia is not only a fertilizer to save agriculture. This combination of nitrogen and hydrogen contains 20 times more energy per weight than lithium batteries. The only upsetting thing is the modern “dirty” methods of ammonia production, which scientists from the USA decided to combat. They succeeded.

Artistic representation of a natural ammonia production plant. Image source: Iwnetim Abate and Yifan Gao

Traditional ammonia production, 80% of which is consumed by agriculture, requires high temperatures and produces greenhouse gas emissions. For every ton of this compound, 2.4 tons of carbon dioxide are released into the atmosphere. Overall, this niche of the chemical industry is responsible for 1% of our civilization’s contribution to annual anthropogenic gas emissions. Therefore, attempts are being made to produce ammonia using renewable energy, making it clean in every sense.

In August last year, the world’s first ammonia production plant was launched in Denmark using solar and wind energy. Production can produce up to 5,000 tons of ammonia per year. If we talk about ammonia as green fuel, then internal combustion engines on ammonia have already been developed. There are a number of models of vehicles on this fuel, as well as it is planned to launch water in 2026 in Norway in the world’s first container truck on ammonia.

Scientists from the Massachusetts Institute of Technology (MIT) have found a way of almost natural reproduction of ammonia without involving any artificial sources of energy. The phenomenon discovered back in the 80s pushed the opening when one of the wells in Mali began to issue pure hydrogen. Scientists concluded that deep underground, with the involvement of rocks and the temperature of the subsoil, are processes that naturally produce hydrogen from water in rocks.

«It was a great moment, the researchers say. “We may be able to use the Earth as a factory, using its heat and pressure to produce valuable chemicals such as ammonia in a cleaner way.”

Based on this assumption, the scientists built a model system for injecting nitrogen-rich water into iron-rich synthetic minerals, simulating the rocks that lie beneath the earth’s surface. The process produced ammonia without the formation of any CO2 and without the need for any additional external energy to activate the chemical process.

At the second stage, researchers replaced the synthetic breed Olivin, which in nature is found everywhere and is also rich in iron. A copper catalyst was also added and heated to 300 ° C. About this temperature will be at a depth of several kilometers under the surface of the earth. It was found that nitrogen in water reacts with iron in the breed with the formation of pure hydrogen, which, in turn, reacts with nitrogen with the formation of ammonia. As a result of the process, a tons of Olivin received 1.8 kg of ammonia.

A similar method can be implemented anywhere in the world, because olivine is found everywhere. Moreover, ordinary wastewater, usually saturated with ammonia, can even be injected underground. It is literally an inexhaustible source of clean energy. Scientists reported on the discovery in the journal Joule and applied for a patent. In practice, they hope to conduct the experiment within the next year or two.