Impact of fuel type on the performance of a solid oxide fuel cell integrated with a gas turbine

This study investigates the performance of a flame-assisted fuel cell integrated with a gas turbine operating with six fuels (CH4, C3H8, JP-4, JP-5, JP-10, and H2). A thermodynamic model is developed for the fuel-rich combustion, fuel-lean combustion and each step of the gas turbine including the compressor, turbine and recuperator in order to analyze the overall hybrid gas turbine cycle. As the fuel/air equivalence ratio increases, the hybrid system efficiency increases initially then decreases despite increasing hydrogen concentration in the exhaust. The peak efficiency occurs around an equivalence ratio of 2 for all fuels. The optimal performance of the hybrid system utilizes H2 as the fuel. The peak electrical efficiency of the hybrid setup is 64.7% with H2 fuel, 60.3% with CH4 fuel, 60.9% with C3H8 fuel, 61.7% with JP-4 fuel, 61.0% with JP-5 fuel and 61.2% with JP-10 fuel, representing a significant increase over the standard gas turbine cycle. With H2 fuel, the overall integrated system is predicted to be 24.5% more efficient than the standard gas turbine system. These results show promise for a fuel flexible hybrid gas turbine which could benefit the growing aircraft industry as the desire for a more electric airplane increases.