Ammonia as a Hydrogen Carrier: Energetic Assessment of Processes Integrated with Fuel Cells for Power Generation

In the context of the near-future hydrogen economy, ammonia is regarded as one of the most promising hydrogen carriers in the short-to-medium term. As part of the broader transition to a new energy paradigm, the well-established and extensive ammonia infrastructure can serve as a platform for green hydrogen transportation, storage, and utilization. This study analyzes various process configurations integrated with different types of fuel cells for ammonia utilization through Aspen Plus simulations. The evaluation focuses on overall energetic efficiency (ranging from 31.20 to 51.50% depending on the adopted configuration), autothermality (42.00 to 100.00%, based on the adopted process configuration), and emissions from external heat sources (0.03-0.07 kg_CO2/kWh). Assessments are conducted parametrically across different fuel cell efficiencies (50.0-65.0%). Results suggest that high-temperature PEMFC and direct ammonia solid oxide fuel cells (SOFCs) offer a balance between overall efficiency (40.2-51.5 and 35.00-52.0%, respectively) and feasibility of achieving autothermal operations under nitrogen dilution (up to 25.0%). Considering technological maturity and operational lifespan, high-temperature PEMFCs and SOFCs emerge as a promising component for such integrated systems.