A groundbreaking prototype device introduces a novel method for creating ammonia, a crucial element in fertilizers, potentially revolutionizing an industry that contributes roughly one-third of global greenhouse gas emissions.
Our atmosphere holds a promising solution for enhancing sustainable agriculture. Researchers from Stanford University and King Fahd University of Petroleum and Minerals in Saudi Arabia have created a prototype that generates ammonia—a vital fertilizer component—by utilizing wind energy to move air through a specialized mesh. If this method is refined, it could replace a century-old practice that synthesizes ammonia by mixing nitrogen and hydrogen at extremely high temperatures and pressures. This traditional method utilizes 2% of the world’s energy and emits about 1% of the annual carbon dioxide due to its dependence on natural gas.
The findings, published on December 13 in Science Advances, showcased the technology in a real-world setting rather than just in a laboratory. The researchers hope to eventually integrate this device into irrigation systems, allowing farmers to produce fertilizer directly from the air.
“This advancement enables us to utilize the nitrogen available in our atmosphere to create ammonia in a sustainable way,” said Richard Zare, a senior author of the study and a professor at Stanford’s School of Humanities and Sciences. “It’s a major leap towards a more decentralized and eco-friendly agricultural practice.”
A cleaner alternative
Before developing their device, the team investigated how various environmental factors—including humidity, wind speed, salinity, and acidity—impact the production of ammonia. They analyzed how droplet size, solution concentration, and the interaction of water with insoluble materials influence the process. Additionally, they assessed the optimal combination of iron oxide and an acid polymer with fluorine and sulfur to determine ideal ammonia production conditions and the relationship between these catalysts and water droplets.
The Stanford team’s method produces ammonia in a clean and cost-effective manner, using air to extract nitrogen and hydrogen from water vapor. By passing air through a catalyst-coated mesh that promotes the necessary reactions, they generated a sufficiently concentrated ammonia solution suitable for hydroponic use in greenhouses. Unlike conventional techniques, this innovative approach operates at room temperature and normal atmospheric pressure, without needing an external power source connected to the mesh. This allows farmers to use the portable device on-site, avoiding the need to buy and transport fertilizer from manufacturers.
“This method significantly decreases the carbon impact of ammonia production,” stated Xiaowei Song, the lead author and a chemistry research scientist at Stanford.
In their laboratory tests, the team further showcased the technology’s potential by reusing water in a spraying system, achieving ammonia concentrations adequate to fertilize greenhouse plants within just two hours. By incorporating a filter made from microporous stone, this strategy could provide enough ammonia for wider agricultural use.
A future without fossil fuels
The device is projected to take two to three years before it can be marketed, according to Chanbasha Basheer, a study co-author from King Fahd University of Petroleum and Minerals. In the meantime, the researchers intend to scale up the mesh systems to enhance ammonia production rates. “There’s significant potential for further development,” Basheer noted.
Beyond its role in fertilizers, ammonia serves as a clean energy carrier, facilitating more efficient storage and transportation of renewable energy compared to hydrogen gas, given its higher energy density. This breakthrough positions ammonia as a crucial element in reducing carbon emissions in sectors such as shipping and energy production.
“Green ammonia signifies a new era in sustainability,” Zare remarked. “If we can scale this method economically, it could dramatically lessen our reliance on fossil fuels in various industries.”
This study received funding from the U.S. Air Force Office of Scientific Research and King Fahd University of Petroleum and Minerals.
