Exergoenvironmental comparison of internal reforming against external reforming in a cogeneration system based on solid oxide fuel cell using an evolutionary algorithm

Two different arrangements of a system including a cogeneration plant based on solid oxide fuel cell with internal reforming (IR-SOFC) and solid oxide fuel cell with external reforming (ER-SOFC) for producing power and hot water are modeled and analyzed thermodynamically. Also, in order to determine the optimal values of design parameters including SOFC inlet temperature, current density, steam-to-carbon ratio, and fuel utilization factor, an evolutionary algorithm for multi-objective optimization purposesis applied. For both systems, two objective functions including the exergy efficiency and CO2 gas emission (EMI) in kg/MWh, with the aim of maximizing the exergy efficiency and minimizing the EMI are considered. The optimization results revealed that at the final optimal design point, the value of the exergy efficiency of the cogeneration system based on IR-SOFC is about 9.6% more than that of the system based on ER-SOFC. Moreover, the amount of EMI in the first configuration (cogeneration system based on IR-SOFC) is about 1.4% lower than that of the second one (cogeneration system based on ER-SOFC).