A case study: Exergoeconomic analysis and genetic algorithm optimization of performance of a hydrogen liquefaction cycle assisted by geothermal absorption precooling cycle

The present paper deals with the hydrogen liquefaction system with absorption precooling cycle assisted by geothermal energy is modeled and analyzed as an exergoeconomic. Uses part of the geothermal water heat for absorption refrigeration to precool the hydrogen gas and part of the geothermal water heat to produce work with a binary geothermal cycle and use it in a liquefaction cycle. Exergoeconomic optimization procedure is applied using genetic algorithm method to the integrated system. The objective is to minimize the unit cost of hydrogen liquefaction of the composed system. Based on optimization calculations, hydrogen gas can be cooled down to −30 °C in the precooling cycle. The actual work consumption in the hydrogen liquefaction is calculated to be 10.06 kWh/kg LH2. The unit exergetic liquefaction cost of hydrogen is calculated to be 1.114 $/kg LH2 or 9.27 $/GJ, respectively in the optimum case.