Abstract
Feeding the world has always required more than innovation. It demands reflection on the consequences of that innovation. My capstone project focuses on the technical design and optimization of an industrial urea production process, undertaken to address the growing global demand for fertilizer while reducing energy consumption and carbon emissions. Specifically, the project explores improvements to conventional ammonia and urea synthesis systems through process optimization, advanced catalysts, and efficient recycling loops. Furthermore, my STS research paper examines the broader sustainability of fertilizer systems, motivated by the environmental degradation and global inequities associated with their production and use. This research investigates how fertilizer sustainability is shaped not only by engineering processes but also by economic systems, governance structures, and social inequalities. These two projects are deeply intertwined. While the capstone proposes technical solutions to improve efficiency and reduce emissions, the STS research highlights that technological innovation alone cannot solve systemic environmental harm and inequitable access. Together, they demonstrate that fertilizer sustainability is a sociotechnical challenge requiring both engineering advancements and systematic change.
The capstone project addresses a critical problem: current urea production is energy-intensive and produces significant greenhouse gas emissions. To contribute toward a solution, the project designs a full-scale ammonia–urea production plant using Aspen modeling, incorporating processes such as steam methane reforming, water-gas shift, CO₂ scrubbing, ammonia synthesis, and urea synthesis. There is extensive emphasis on improving efficiency through heat integration, optimized reactor conditions, and the use of ruthenium-based catalysts to increase ammonia conversion while reducing operating conditions. The design also integrates recycling systems to minimize waste and maximize material utilization, particularly in the urea synthesis loop where unreacted ammonia and carbon dioxide are continuously recovered.
Overall, the capstone concludes that process optimization can significantly improve industrial performance by reducing energy demands, increasing conversion efficiency, and lowering emissions. The final design achieves near agricultural-grade urea purity while maintaining economic feasibility and aligning with industry-scale production standards. Additionally, incorporating CO₂ capture and reuse within the process demonstrates how engineering design can partially mitigate environmental impact while maintaining productivity.
The STS research paper investigates the question: how can fertilizer systems be made sustainable when they are embedded within complex social, political, and economic networks? This question is significant because fertilizers are essential for global food production, yet their production and use contribute to climate change, ecosystem degradation, and global inequality. To answer this, the research applies Actor Network Theory and political ecology frameworks, using qualitative methods such as document analysis and comparative case studies to examine fertilizer use across different global regions.
The findings reveal that fertilizer sustainability is not limited by technological innovation, but by the structure of the systems in which those technologies operate. While engineering innovations can reduce emissions, energy, and improve efficiency, their adoption is constrained by economic incentives, institutional resistance, and unequal global distribution networks. The research concludes that meaningful progress requires systemic change, including policy reform, improved governance to encourage change, and more equitable resource distribution.
