Thermodynamic analysis of low-temperature and high-pressure (cryo-compressed) hydrogen storage processes cooled by mixed-refrigerants

Cryo-compressed hydrogen (CcH 2 ) is a promising hydrogen storage method with merits of high density with low power consumption. Thermodynamic analysis and comparison of several CcH 2 processes are conducted in this paper, under hydrogen storage conditions of 10–100 MPa at 60–100 K. Mixed-refrigerant J-T (MRJT), nitrogen/neon reverse Brayton (RBC) and hydrogen expansion are employed for cooling hydrogen, respectively. Combined CcH 2 processes such as MRJT + neon-RBC are proposed to reach higher CcH 2 density at lower temperatures (<80 K). It was indicated that the specific power consumptions ( SPC ) of MRJT processes are obviously lower than those of nitrogen/neon-RBC or hydrogen expansion processes. For a typical storage condition of 50 MPa at 80 K, MRJT CcH 2 process could achieve hydrogen density of 71.59 kg m −3, above liquid hydrogen. While its SPC of 6.42 kWh kg −1 is about 40% lower than current dual-pressure Claude hydrogen liquefaction processes (10.85 kWh kg −1 ).