Substitution of a Conventional Gas Turbine By a HT-PEMFC APU: Feasibility Study

The aviation industry is increasing leading to a harmful environmental impact. APU is liable for 20% of airport ground-based emissions, 50% of aircraft maintenance costs and more than 5% of the daily fuel consumption [1]. Aware of this growing problem and its consequences, research should be conducted targeting new, non-polluting energy sources capable of meeting or even exceeding the aircraft’s electrical needs. With this in mind, the main goal of this article was to analyze the feasibility of implementing a HT-PEMFC system as a more sustainable alternative for the gas turbine APU in  an Airbus A320. The fuel used was methane which requires a fuel processor to convert it into hydrogen before entering the fuel cell. The maximum output work of this methane-supplied system is estimated at 250 kW. Therefore, a fuel processor and a fuel cell mathematical models were required. The two models along with the thermodynamic analysis were performed in MATLAB. The aims of this project were to evaluate fuel processing of methane and its conversion into electric energy through a fuel cell; to perform the thermodynamic analysis of HT-PEMFC APU based on the first and second laws of thermodynamics; and estimate the total weight, emissions and fuel consumption of the HT- PEMFC APU. The results of this research were  very encouraging, as it shows that the breakeven weight of the HT-PEMFC, for a mass increment of 854 kg, was compensated by a fuel efficiency of ∼2.7 times the conventional APU. Keywords: APU, HT-PEMFC, Fuel cell