M. Taghavi - Department of Mechanical Engineering, Nour Branch, Islamic Azad University, Nour, Iran.
H. Salarian - Department of Mechanical Engineering, Nour Branch, Islamic Azad University, Nour, Iran.
B. Ghorbani - Faculty of Engineering Modern Technologies, Amol University of Special Modern Technologies, Amol, Iran.

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 ۵۵۵۹ kW of power from PVC unit, ۶۰.۷۹ kg/h of natural gas, ۸۰۰۰ kg/h of liquid air and ۱۰۲۸ 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 V۱۰ 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 ۴.۲۴۹ years, ۵.۴۳۲ USD/kg LH۲ and ۱.۵۶۷ USD/kg LH۲, respectively. The economic sensitivity examination of the combined system reveals POR increases from ۲.۲۹۵ to ۱۳.۹۷ years and net annual profit decreases from ۳۲.۶۶ to ۵.۳۶۶ MMUSD/year by increasing the gaseous hydrogen cost from ۱.۴ to ۳.۴ USD/kg LH۲. Moreover, POR increases from ۲.۷۵۳ to ۲۵.۰۷ years and levelized cost of product increases from ۵.۰۲ to ۷.۴۸۸ US/kg LH۲ by increasing the capital cost from ۵۲.۵ to ۲۱۷.۵ MMUSD.

Hydrogen liquefaction, Liquid air cold energy recovery, Photovoltaic (PV) panels, Sensitivity Analysis, Economic evaluation