CO2 を削減して空気の成分から重要な肥料を作る新デバイス (New device produces critical fertilizer ingredient from thin air, cutting carbon emissions)

2024-12-13 アメリカ合衆国・スタンフォード大学

＜関連情報＞

• https://news.stanford.edu/stories/2024/12/new-device-produces-critical-fertilizer-ingredient-from-thin-air
• https://www.science.org/doi/10.1126/sciadv.ads4443

空気中の水蒸気と窒素からオンサイトでアンモニアを合成する Onsite ammonia synthesis from water vapor and nitrogen in the air

Xiaowei Song, Chanbasha Basheer, Jinheng Xu, and Richard N. Zare
Science Advances  Published:13 Dec 2024
DOI:https://doi.org/10.1126/sciadv.ads4443

Abstract

An innovative method for onsite ammonia synthesis under ambient conditions has been developed using a catalyst mesh composed of magnetite (Fe₃O₄) and Nafion polymer. We pass air through the catalyst, which condenses microdroplets from atmospheric water vapor and uses nitrogen from the air, resulting in ammonia concentrations ranging from 25 to 120 μM in 1 hour, depending on local relative humidity. Operated at room temperature and atmospheric pressure, this technique eliminates the need for additional electricity or radiation, thereby substantially reducing carbon dioxide emissions compared to the traditional Haber-Bosch process. In laboratory experiments, we further optimized the reaction conditions and scaled up the process. After 2 hours of spraying, the ammonia concentration increased to 270.2 ± 25.1 μM. In addition, we present a portable device designed for onsite ammonia production which consistently produces an ammonia concentration that is adequate for some agricultural irrigation purposes.