Document Type
Dissertation
College
College of Engineering
Department
Industrial and Engineering Management
Degree
PhD in Engineering Management
Dissertation Defense Date
2025-07-30
First Committee Member
Barron, Robert
Second Committee Member
Salmon, Christian
Third Committee Member
Ekong, Joseph
Additional Committee Member(s)
Schlef, Katherine
Abstract
Ammonia feeds the world: about half of the world’s food is produced using synthetically produced ammonia fertilizer (Iriawan et al., 2021; Ritchie, 2017). However, current ammonia production leaves a large carbon footprint, and it has become imperative for researchers to investigate less carbon-intensive production alternatives. The dominant fossil-based ammonia production technology contributes about 1.8% of global carbon dioxide emissions (Ojelade et al., 2023; Osorio-Tejada et al., 2022). Renewable energy powered ammonia production is one of the ways to generate carbon-free ammonia. Understanding the impact of renewable-powered ammonia on local and global rural agriculture is vital for making investment decisions. This dissertation models renewable-powered ammonia and examines its impact in the US and global context.
This dissertation has five (5) parts. Part 1 provides the background and motivation for this study. In the background literature, we discuss Food Energy and Water (FEW) nexus and the challenges affecting small and rural agricultural communities. Following that, we discuss how this research is addressing the FEW challenges that small and rural agricultural communities confront. We then highlight the ammonia industry and its contribution to the agricultural sector. We discuss the dominant fossil-based fertilizer production technology and its impact on agriculture. Next, we review alternate ammonia production technologies which are less carbon intensive. This introduces us to renewable-powered ammonia production. We identify some impact of renewable-powered ammonia on agriculture FEW nexus systems. Given the integrated nature of FEW nexus systems, an integrated assessment approach is essential to understanding the effects of green ammonia adoption. We discuss the current state of the art in Integrated Assessment modeling of renewable-powered ammonia and its impacts. Finally, we identify the gap in current research and conclude with a discussion of the research objective, problem definition, and research questions of this dissertation.
Parts 2, 3, and 4 state and answer the research questions of this study. In part 2, we conduct a systematic review of all techno-economic literature available on green ammonia production and synthesize the cost information to establish a plausible range of green ammonia production costs. We also identify key cost drivers of green ammonia production. We establish two plausible cost ranges for green ammonia production based on the reviewed literature: $1.17 to $16.60 per kg of hydrogen (H₂) and $380 to $2,603 per ton of ammonia (NH₃). These values are derived from reported estimates across studies. We also identified energy cost as a key cost driver of green ammonia production, accounting for an average of 57% of the total production cost in systems powered by wind and solar energy.
In Part 3, we discuss the methodology for modeling green ammonia with an Integrated Assessment Model known as the Global Change Analysis Model (GCAM). We assess the outcomes of decarbonizing US agriculture using renewable-powered ammonia and its impacts on FEW nexus. We find that green ammonia impacts prices of fertilizer, fertilizer production, carbon emissions and the FEW nexus, affecting water withdrawal levels and land use in the US.
In part 4, we extend the insight and analysis of part 3 to the global context by analyzing the impact of renewable-powered ammonia in small agricultural communities around the world. Using the modified GCAM version explained in Chapter 3, we analyze the socioeconomic and environmental impacts of replicating renewable-powered ammonia in other regions of the world. We find that green ammonia becomes price-competitive with fossil-based ammonia, impacting global fertilizer production, food production and reducing global emissions.
In part 5 we summarize and discuss our results, conclusions, recommendations, and topics for future work.
Recommended Citation
Nyarko, Nanaadom Abayie Ph.D, "An Integrated Assessment of Green Ammonia Adoption: Implications for the US Agriculture Sector, the Global FEW Nexus, and Environmental Outcomes" (2025). Doctoral Dissertations - College of Engineering. 19.
https://digitalcommons.law.wne.edu/coedissertations/19
