Journal of Energy Engineering, vol.143, no.6, 2017 (SCI-Expanded)
© 2017 American Society of Civil Engineers.In this paper, a molten carbonate fuel cell (MCFC)-heat engine hybrid system is investigated in terms of the environment and sustainability. The MCFC is a premier power generator, and the high-temperature waste heat supplied by the fuel cell is used as a heat source at an irreversible heat engine. This irreversible heat engine is the secondary power generator of the system. The thermo-environmental function and exergetic sustainability index are applied to design an environmentally friendly MCFC-heat engine hybrid system. Results are obtained numerically, and an ecologically friendly operation range is attempted to determine the considered system. According to calculations, the maximum power density of the hybrid system is 4,242.62 Wm-2, and the maximum thermo-environmental function density and the exergetic sustainable index are equal to 0.0309 Wmpts-1 m2 and 107.36, respectively. Finally, it is recommended that current density should be chosen between current density at the maximum exergetic sustainable index and current density at the maximum thermo-environmental function for a less environmentally harmful system.