Economic Evaluation of a Hybrid Hydrogen Liquefaction System Utilizing Liquid Air Cold Recovery and Renewable Energies

The present study economically evaluates a combined hydrogen liquefaction configuration using combined heat and power system, photovoltaic cells 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. 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 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, prime price of liquid hydrogen production and additive value are 4.249 years, 5.432 USD/kg LH2 and 1.567 USD/kg LH2, 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/kg LH2. Moreover, POR increases from 2.753 to 25.07 years and levelized cost of product increases from 5.02 to 7.488 US$/kg LH2 by increasing the capital cost from 52.5 to 217.5 MMUSD.