Optimization models for techno-economic and environmental analysis of hydrogen supply chains: A Brazilian case study

The expansion of low-carbon hydrogen supply chains calls for integrated planning frameworks capable of capturing interactions among products, infrastructure, and environmental constraints. In Brazil, this challenge is intensified by the country's continental scale, heterogeneous regional conditions, strong interdependencies between hydrogen and ammonia markets, and the need to manage greenhouse gas (GHG) emissions. This article proposes an integrated mixed-integer linear programming (MILP) framework for strategic multi-period and multi-product planning of hydrogen supply chains. The model jointly represents production, transportation, storage, demand allocation, and discrete investment decisions for hydrogen, ammonia, and CO 2 . Key features include the explicit representation of ammonia synthesis from hydrogen and the treatment of CO 2 as a by-product with multiple allocation pathways, including sequestration, whose infrastructure is modeled as a capacity-constrained and expandable operational resource. Results indicate that existing infrastructure and planned investment projects are insufficient to expand hydrogen production capacity in line with demand growth, both for direct hydrogen use and ammonia production, leading to hydrogen supply shortfalls across all simulated scenarios. These shortfalls emerge as the primary bottleneck of the supply chain, influencing investment timing and technology choices. In contrast, ammonia and CO 2 -related infrastructure are sufficient to meet demand and absorb surplus CO 2 emissions not consumed by the market. CO 2 sequestration capacity, on the order of million tonnes per year, nonetheless plays a key role in shaping optimal hydrogen production pathways. Higher sustainability preferences lead to emission-related cost reductions on the order of billions of USD, consistently outweighing moderate increases in total system costs under variations in carbon cost assumptions. The proposed framework provides robust quantitative insights into capacity adequacy and bottlenecks in integrated hydrogen, ammonia, and CO 2 systems, supporting the evaluation of low-carbon transition strategies in emerging hydrogen economies such as Brazil. • An integrated MILP framework enables joint planning of hydrogen, ammonia, and CO 2 supply chains. • GHG sequestration is represented as a capacity-constrained and expandable operational resource. • Hydrogen production capacity is the system's primary bottleneck. • Emission-cost reductions outweigh system-cost increases across scenarios and social cost of carbon sensitivities. • A staged, coordinated transition pathway emerges from the integrated H 2 –NH 3 –CO 2 planning results.