Berta Galan
Ammonia has been traditionally produced in large-scale plants using natural gas as hydrogen source, leading to high energy consumption and significant CO₂ emissions. Green ammonia synthesis is a sustainable alternative, specifically electro-ammonia (e-NH₃), produced from hydrogen via water electrolysis powered by renewable energy. Moreover, advancements in energy integration and decentralized production strategies have increased the interest in small-scale e-NH₃ plants, providing a flexible solution using local renewable sources1.
However, the high capital costs associated with electrolysis-based systems require a detailed cost analysis to determine economic feasibility. Understanding the cost distribution across process units—air separation, electrolysis, and ammonia synthesis—is essential for optimizing plant design and improving the competitiveness of small-scale e-NH₃ plants2,3.
This study presents an economic assessment of a small-scale e-NH₃ production plant. The research applied established cost estimation methodologies, including Guthrie, Seider, Turton, and Matche, to determine equipment costs, highlighting the electrolyzer as the most significant cost driver. From these results, capital expenditures (CAPEX) and operational expenditures (OPEX) were evaluated and compared with literature. Finally, an analysis of the unit cost and the levelized cost of ammonia (LCOA) was conducted, considering various economic scenarios.
Acknowledgment: This study forms part of the ThinkInAzul programme and is supported by Ministerio de Ciencia e Innovación with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Comunidad Autónoma de Cantabria. Project: C17.I01 (AMONSOS) – Plan Complementario de Ciencias Marinas.
