A novel trigeneration system integrating a small modular supercritical CO2-cooled fast reactor (SM-SCFR) with hydrogen production and seawater desalination offers a comprehensive solution to simultaneous energy and water challenges. The system addresses the intermittency limitations of renewable electrolysis while reducing freshwater consumption—two critical barriers to scaling clean hydrogen for hard-to-decarbonize industries.
The proposed design uses a 200 MWth reactor as the thermal source. High-temperature heat directly powers high-temperature steam electrolysis (HTSE) to produce hydrogen, while rejected waste heat drives a multi-effect distillation (MED) desalination plant. This cascading exergy approach converts thermal losses into productive outputs, eliminating the zero-sum trade-off typical in conventional systems.
Process modeling demonstrates stable integration with approximately 53% cogeneration efficiency. The system operates in two modes: a fully self-sufficient configuration for complete water autonomy, and a semi-integrated market-led (SML) mode optimized for commercial viability. The SML configuration achieved a levelized cost of hydrogen of $2.93 per kilogram at approximately 550 metric tons daily production capacity. Notably, the MED desalination plant accounts for only 0.6% of total capital investment while significantly improving economics and operational flexibility.
The framework employs power loss factor (PLF) and gain output ratio metrics to evaluate thermodynamic performance across operational modes. This quantitative foundation enables operators to balance hydrogen, electricity, and freshwater outputs based on market demand and grid requirements.
Beyond economic metrics, this integrated approach eliminates three critical dependencies: carbon from conventional steam reforming, intermittency from renewable-only pathways, and freshwater scarcity constraints. For coastal regions and industrial clusters requiring simultaneous hydrogen feedstock and desalinated water, small modular reactors operating under this tri-generation model offer resilient, carbon-free production with proven techno-economic viability.
