Exergetic, economic, and environmental evaluations and multi-objective optimization of a combined molten carbonate fuel cell-gas turbine system

The principal goal in the present work is to model a molten carbonate fuel cell-gas turbine (MCFC-GT) hybrid plant from energetic, exergetic, economic and environmental standpoints and to optimize the system through a multi-objective optimization scheme. Two conflicting objectives including exergetic efficiency and total cost rate of the system are introduced for multi-objective optimization. TOPSIS decision-making method is employed to determine the system final optimum design, leading to an overall exergetic efficiency of 51.7% and the total cost of 0.324 million USD per year. Moreover, a sensitivity analysis of the Pareto frontier to fuel unit cost and effective interest rate has been performed to investigate the variation of objective functions with economic parameters. Finally, a sensitivity analysis on the optimization results was performed for some of the key parameters, revealing the fact that operating pressure of the system has the highest impact on the exergetic efficiency compared to the other operating parameters.