Arash Nourbakhsh; Mahdi Nami Khalilehdeh; Saman Faramarzi; Mostafa Mafi
Abstract
Given the importance of using hydrogen fuel as one of the best sustainable energy sources, different hydrogen liquefaction technologies are developed to store and transport it ...
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Given the importance of using hydrogen fuel as one of the best sustainable energy sources, different hydrogen liquefaction technologies are developed to store and transport it over long distances. Process integration with other cycles and new high-efficiency liquefaction cycles can make hydrogen fuel more economically viable, especially for liquid hydrogen exporter countries like Iran. In this study, a hydrogen liquefaction cycle with a capacity of 1.5 tons per day is integrated with a liquefied natural gas (LNG) production process. Energy, exergy, and economic analyses are implemented to examine the proposed cycle. The novelty of this paper is based on two points: first, simultaneous production of liquefied hydrogen (LH2) and LNG in one process with an innovative configuration that leads to better performance compared to that of similar cycles, and second, simultaneous use of two-equation of states (EOS) for pure hydrogen and mixed refrigerant streams. Process integration of the LNG system with the hydrogen liquefaction unit reduces the capital expenditures (CAPEX) and operating expenses (OPEX) for both systems. Components with the greatest exergy destruction are identified. The coefficient of performance (COP) and the figure of merit (FOM) are 0.89 and 0.72, respectively. Specific energy consumption (SEC) of the proposed cycle is 5.31 kWh kg^(-1), +25 % more efficient than the similar hydrogen liquefaction cycle in the literature. The annual total cost for the proposed cycle is $35.6 million, including CAPEX, OPEX, and operation and maintenance expenditures (O&M).
