Design and operation of Power-to-Ammonia systems: A review

• Published in: Energy conversion and management Vol. 327; p. 119494
• Main Authors: Narciso, Diogo A.C., Pires, José M., Fortunato, João, Teixeira, Paula, Castro, Pedro M., Pinheiro, Carla I.C., Matos, Henrique A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2025
• Subjects: administrative management; ammonia; carbon footprint; climate change; Design; electrochemistry; electrolysis; energy conversion; greenhouse gases; hydrogen; hydrogen production; industrial applications; manufacturing; methane; power generation; Power-to-Ammonia; Process Flexibility; Renewables; steam; Design; Process Flexibility; Power-to-Ammonia; Renewables
• ISSN: 0196-8904
• DOI: 10.1016/j.enconman.2025.119494

•Design strategies for Power-to-Ammonia systems are reviewed in detail in this work.•This includes system architecture, design principles and key flexibility assumptions.•A critical assessment of the key factors and challenges in this field is presented. Climate change concerns have led to increasing decarbonization initiatives in the chemicals sector. The manufacture of ammonia via the Haber-Bosch process contributes 1–2% of global greenhouse gas emissions, making it a priority in this context. Several alternative routes to the Haber-Bosch process are under investigation, namely new electrochemical and plasma-based processes. All are still far from industrial application and so, Power-to-Ammonia (P2A) holds the greatest promise for green ammonia manufacture in the short term. In P2A systems, conventional hydrogen production is replaced by renewable powered water electrolysis, which avoids the high carbon footprint of the Steam Methane Reforming route. The boundaries of P2A systems, however, extend beyond the conventional chemical process units and consider also renewable power generation, grid interaction and the operation of auxiliary buffer units, such as hydrogen storage and/or batteries. The design of these systems is complex, requiring careful articulation between multiple units with limited flexibility and compounded by the varying and to some extent unpredictable nature of renewable resources. Efficient design strategies are key to manufacture and sell green ammonia at competitive prices and promote the widespread adoption of P2A systems. In this paper, a review of scientific papers published on this subject is presented. The focus is specifically on P2A architectures reported in the literature, design methodologies and the key flexibility assumptions in process units. A critical assessment of the field is presented, highlighting the key design considerations identified in this review. Some challenges and ideas for future work on P2A design are also identified.