Celma de Oliveira Ribeiro is an Associate Professor of Industrial Engineering at the University of São Paulo
Brazil is the world’s largest soybean producer (161 Mt) and the third-largest producer of corn (135 Mt) in the 2024–2025 harvest. Brazil’s corn production is strongly linked to the soybean supply chain. In the Center-West region, corn is predominantly cultivated as a second crop, immediately after soybean harvesting on the same farmland. This spatial and seasonal overlap results in the same regions being among the world’s largest producers of both crops. Nitrogen fertilizers play a critical role in sustaining corn yields, especially in the Center-West region, where production is highly concentrated. However, both fertilizer manufacturing sites and import entry points are located over 1,000–1,500 km from major consumption areas, leading to high logistics costs and supply vulnerability. Moreover, domestic ammonia production remains strongly dependent on natural gas. Today, nearly all ammonia in Brazil is produced in large-scale Haber–Bosch plants (≈1,000 t/day), located far from the agricultural demand centers. Developing smaller units (10–100 t/day) would enable production closer to consumers, reducing transportation costs and dependency on long supply chains. This shift toward distributed green ammonia could enhance supply security and align production with the geography of agricultural demand.
This seminar presents a concept for decentralized green ammonia production in Brazil, using Mato Grosso—the country’s leading corn producer—as a representative case study. Based on municipal-level data from IBGE, a techno-economic assessment evaluates the CAPEX, OPEX, and competitiveness of distributed green ammonia relative to gray and blue alternatives. A mixed-integer nonlinear programming (MINLP) model is applied to determine the optimal location and sizing of decentralized plants while minimizing the Levelized Cost of Ammonia (LCOA). A sensitivity analysis is also performed to identify the key techno-economic drivers influencing these decisions, such as renewable electricity prices, electrolyzer performance, and transportation costs. The results indicate a clear trade-off between economies of scale and delivery distances, supporting distributed green ammonia as a promising and cost-effective strategy to supply regional fertilizer demand.
Bio: Celma de Oliveira Ribeiro holds a B.S. in Computer Science from the University of São Paulo (USP) and a Ph.D. in Industrial Engineering from the same institution, followed by a postdoctoral fellowship at the University of Porto, Portugal. She has been an Associate Professor at the Department of Industrial Engineering at the Polytechnic School of USP since 2019, where she currently serves as Deputy Head of the department. She is also an affiliated researcher at the Department of Chemical Engineering at USP.
Prior to her academic career, Celma worked at Ultragaz, a major Brazilian liquefied petroleum gas distribution company. Her research interests include optimization, mathematical modeling, and data science applied to engineering problems in the context of the energy transition. She develops decision-support models under uncertainty incorporating financial, environmental, and technological risks. She receives continuous research funding and holds a productivity fellowship from Brazilian research agencies.
Originally published at environmentalchange.nd.edu.