Synergistic analysis via Aspen and MATLAB of cryo-compressed hydrogen production process based on liquid nitrogen cooling including pre-cooling

Hydrogen, as a clean energy source, is playing an increasingly prominent role in the energy sector, and hydrogen storage technology constitutes a critical link for the large-scale application of the hydrogen energy industry chain. Among various storage technologies, Cryo-compressed hydrogen storage has attracted significant attention due to its advantages such as low energy consumption, high hydrogen storage density, and flexible adaptation to scenarios. However, technical bottlenecks still exist in its production process. To obtain high-purity nitrogen, cryogenic air separation technology needs to be adopted for separation. However, the cold exergy of the resulting liquid nitrogen(LN2) is severely wasted. This paper proposes a Cryo-compressed hydrogen production process based on LN2 cooling. By designing a process involving ambient temperature hydrogen precooling, multi-stage compression with inter-stage cooling, and final cooling, the cold exergy of LN2 is fully utilized to optimize the system’s energy consumption and costs. This study conducts process simulations by combining Aspen Plus and MATLAB, systematically analyzing the impacts of compression stages, temperature, and pressure parameters on system energy consumption. The results indicate that the adoption of this process for producing cryogenic high-pressure hydrogen can effectively reduce compressor power consumption and heat transfer requirements. When LN2 is used as the sole cold fluid, the exergy efficiency of the system reaches its optimal value at 80K, approaching 55%. The density of cryo-compressed hydrogen at 50MPa@80K (71.59 kg/m3) can exceed that of Liquid hydrogen (LH2), while its specific energy consumption (SEC) is only 3.427 kWh/kgH2, much lower than that of LH2. This implies that the use of cryo-compressed hydrogen exhibits better economic performance in certain scenarios. This process has stronger implementation advantages in regions with concentrated air separation capacity and convenient LN2 supply, as it can better leverage local resources to achieve efficient production, making it suitable for promotion and application in industrial clusters or areas with concentrated hydrogen demand.