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Abstract
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Liquefaction systems are among the physical techniques of hydrogen (H2) storage with high specific power consumption (SPC), high manufacturing cost and inevitable boil-off losses. Liquid air cold (LAC) recovery is among the strategies that could be used to reduce energy consumption of these systems. The present study economically evaluates a combined hydrogen liquefaction configuration using combined heat and power system (CHP), photovoltaic cells (PVC) unit and liquid air energy recovery for precooling under climatic states of Yazd, Iran. The LAC recovery is used to precool hydrogen. Moreover, the cascade refrigeration systems with helium and hydrogen refrigerants are employed to supply refrigeration and liquefaction. Liquid air along with natural gas enters the CHP after cold energy recovery and compression and supplies a part of the power demand of liquefaction structure. The rest of the power required for refrigeration cycles to liquefy hydrogen is supplied by PVC unit. This integrated structure generates liquid hydrogen by receiving 5559 kW of power from PVC unit, 60.79 kg/h of natural gas, 8000 kg/h of liquid air and 1028 kg/h of gaseous hydrogen as inputs. The annualized cost of the configuration (ACC) is applied to economically evaluate the hydrogen liquefaction system using renewable energies. The developed integrated structure is economically evaluated by HYSYS V10 software and m-file code in the MATLAB package. The economic research results of the hybrid cycle indicate the period of return (POR), prime price of liquid hydrogen production and additive value (AV) are 4.249 years, 5.432 USD/kgLH2 and 1.567 USD/kgLH2, respectively. The economic sensitivity examination of the combined system reveals POR increases from 2.295 to 13.97 years and net annual profit decreases from 32.66 to 5.366 MMUSD/year by increasing the gaseous hydrogen cost from 1.4 to 3.4 USD/kgLH2. Moreover, POR increases from 2.753 to 25.07 years and levelized cost of product increases from
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