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Storage and transfer of hydrogen (H 2) from production sites/plants to large-scale demanding industries are one of the most challenging obstacles to hydrogen adoption. Hydrogen liquefaction and its chemical storage in the form of ammonia (NH 3) can be used for safe and economic transportation. High energy consumption and carbon dioxide (CO 2) emissions to supply the utility of these systems can limit the production of liquid H 2 and liquid NH 3. Therefore, efficient design and practical strategies to store hydrogen at a large scale with minimal energy consumption and CO 2 emissions are necessary. In this research, an innovative hybrid system for portable hydrogen storage and power generation with zero CO 2 emission through liquefied natural gas (LNG) regasification is developed. The proposed structure includes a cryogenic air separation unit, magnesium–chloride hydrogen production process, ammonia production system, hydrogen liquefaction cycle, and Rankine/oxy-fuel power plants. The heat loss of the proposed structure is utilized to supply the required heat load for the thermo-electrochemical unit. The LNG regasification operation is utilized for pre-cooling the hydrogen liquefaction system and the necessary refrigeration of the air separation process and the final products. The developed structure is fed by 1883 kmol/h LNG, which is converted to 120 kmol/h liquid NH 3 , 180 kmol/h liquid H 2 , 924.5 liquid CO 2 , and 16.09 MW power. The thermal and exergy efficiencies for the designed system are 20.33% and 22.76%, respectively. The results of the exergy investigation reveal that the largest contribution of exergy destruction occurs in heat exchangers (31.27%), combustion chamber (34.65%), and turbines (8.12%). The economic evaluation indicates that the net annual profit, added value, and payback period are 15.93 US$/yr, 0.0779 US$/kWh, and 5.646 yr, respectively, based on the energy potential of Newfoundland and Labrador in Canada. Three-objective optimization approach using the combination of genetic algorithm and neural network exhibits that the energy efficiency and net annual profit based on the Bellman-Zadeh approach increase up to 27.04% and 45.20 US$/MMBTU, respectively, and the irreversibility reduces to 99.4 MW. [Display omitted] • A novel structure for production of power, liquid H 2 , liquid NH 3 , and liquid CO 2 is developed. • The LNG regasification is used in hydrogen liquefaction and air separation systems. • The waste heat of the oxy-fuel power plant is recovered in Mg–Cl unit for hydrogen production. • The system exergy efficiency and payback period are 22.76% and 5.646 yr, respectively. • A combination of the GA and AI is used for optimization. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel system for production and storage of H 2 with net-zero carbon emissions is developed. • High-temperature fuel cells and biogas upgrading unit are efficiently integrated. • Waste heat of the fuel cells is recovered in the Cu-Cl unit for hydrogen production. • Integrated process can generate 108 kmol/h liquid hydrogen and 18.88 MW power. • A hybrid method of the GA and artificial intelligence tools is applied for optimization. Global energy consumption has been exponentially increasing, leading to the depletion of conventional energy sources and a considerable increase in greenhouse gas emissions. The exploitation of sustainable energy sources and the development of innovative methods for mitigation of CO 2 emissions is necessary. Hydrogen (H 2) as a versatile and green fuel can be produced and stored in liquid form using sustainable energy sources through innovative methods. In this paper, a novel optimal hybrid structure is proposed for hydrogen production and storage with net-zero CO 2 emissions. A high-temperature fuel cell is utilized to reduce CO 2 emissions and supply the heat and power needed to produce and liquefy hydrogen. The hybrid configuration employs an electro-thermochemical unit for hydrogen production, molten carbonate fuel cells, a hydrogen liquefaction process, and a biogas upgrading by water scrubbing. A robust combination of meta-heuristic algorithms and artificial intelligence is developed to optimize the investment return period and energy/exergy efficiencies. The fuzzy Bellman-Zadeh, LINMAP, and TOPSIS techniques are also used to make decisions in multi-objective optimization. This innovative configuration generates 108 kmol/h liquid hydrogen, 18.88 MW power, 54 kmol/h oxygen, and 3258 kmol/h hot water. Pinch, sensitivity, exergy, and economic assessments are implemented to evaluate the performance of the hybrid structure. The thermal and exergy efficiencies of the proposed configuration are obtained to be 78.21 % and 64.83 %, respectively. The greatest portions of destructed exergy are resulted from the fuel cells-gas turbine hybrid system (63.63 %), electro-thermochemical unit (25.96 %), and biogas upgrading technology (6.23 %). The returns period on investment, the prime price of electricity, and the net benefit are computed as 4.854 years, 0.0420 US$/kWh, and 15.73 million US$/years, respectively, based on the energy potentials of Newfoundland and Labrador, Canada. [ABSTRACT FROM AUTHOR]

Conventional methods of energy storage are not able to provide long-term storage due to practical and economic constraints. One of the leading methods for long-term energy storage is the use of wind energy to liquefy hydrogen and oxygen. In this study, an integrated structure of hydrogen liquefaction is developed using the wind turbines, Kalina power generation cycle, and electrolyzer. The HYSYS and TRNSYS software packages with MATLAB programming are used to simulate the hydrogen and oxygen liquefaction structure, considering the weather conditions of the province of Newfoundland and Labrador (NL), Canada. This integrated structure produces 2100 kgmol/h of liquid hydrogen by receiving 264.1 MW of power from wind turbines. The waste heat of the hydrogen liquefaction cycle is used to supply the Kalina power generation cycle. Thermal (or energy) integration can reduce the power consumption of the integrated structure by 8.61%. The specific energy consumption, coefficient of performance of the hydrogen liquefaction cycle, and energy efficiency of the Kalina cycle are obtained to be 5.462 kWh/kgH 2 , 0.1384, and 14.06%, respectively. The overall exergy efficiency and total irreversibilities are 58.73% and 112.7 MW, respectively. The exergy analysis of the integrated structure shows that the highest exergy destruction occurs in electrolyzers (83.13%) and heat exchangers (5.93%), respectively. Also, by adding oxygen liquefaction flow to the integrated hydrogen liquefaction cycle, the specific energy consumption and total exergy efficiency are determined to be 1.632 kWh/kg liquids and 59.11%, respectively. The sensitivity analysis to investigate the effects of the important variables on the performance of the integrated structure is also performed. [Display omitted] • Hydrogen liquefaction cycle, Kalina power cycle, and electrolyzer are efficiently integrated. • Wind turbines are used based on weather conditions of Newfoundland and Labrador. • SEC and COP of hydrogen liquefaction cycle are 5.462 kWh/kgH 2 and 0.1384, respectively. • Kalina cycle and exergy efficiencies of the hybrid system are 14.06% and 58.73%. • Integrated process can produce 2100 kgmol/h liquid hydrogen and 1077 kgmol/h oxygen. [ABSTRACT FROM AUTHOR]