Energy-efficient and cost-effective ammonia electrolysis for converting ammonia to green hydrogen

• Published in: Cell reports physical science 2024-09, Vol.5 (9), p.102171, Article 102171
• Main Authors: Zhang, Kui, Han, Yangkai, Zhao, Yun, Wei, Tao, Fu, Jinchen, Ren, Zhiwei, Xu, Xiaozhi, Zhou, Li, Shao, Zhigang
• Format: Article
• Language: English
• Subjects: ammonia electrolysis; ammonia-to-hydrogen conversion; hydroxide exchange membrane; tandem cell; technoeconomic
• ISSN: 2666-3864; 2666-3864
• DOI: 10.1016/j.xcrp.2024.102171

Ammonia (NH3), touted as a promising hydrogen carrier, has received increasing attention. However, the technoeconomic prospects of comprehensive conversion of hydrogen to ammonia and ammonia to hydrogen (H2-NH3-H2) are unclear, and the approach to ammonia-to-hydrogen conversion has not yet reached the full commercialization stage. In this work, we perform a technoeconomic analysis of a H2-NH3-H2 conversion system, including synthesis, storage and transportation, and ammonia-to-hydrogen conversion, where we particularly compared thermal ammonia cracking with ammonia electrolysis. We find that ammonia electrolysis has a significant economic advantage thanks to its low energy consumption and capital cost. With this as motivation, we develop an energy-efficient and durable ammonia electrolyzer with an energy consumption of 0.84 kWh Nm−3 H2 and a continuous operation for 317 h at 100 mA cm−2. In addition, we also innovate a tandem cell to produce hydrogen without any electric power supply by coupling fuel-cell and electrolysis technologies. [Display omitted] •A technoeconomic analysis of H2-NH3-H2 conversion system is demonstrated•The ammonia electrolyzer uses a low energy consumption of 0.84 kWh Nm−3 H2•Ammonia-based hydrogen production tandem cell with no electrical input is developed Zhang et al. show a scenario where ammonia as a hydrogen carrier has the lowest cost in the process of production, storage and transportation, and conversion, especially for ammonia-to-hydrogen conversion through ammonia electrolysis. An ammonia electrolyzer with low energy consumption is developed for converting ammonia into hydrogen.