Environmental impact assessments of different auxiliary power units used for commercial aircraft by using global warming potential approach.

In this paper, environmental impact analysis is applied to the various auxiliary power units (APUs) used for commercial aircraft in air transportation sector. The exhaust emissions of different auxiliary power units used in commercial aircraft are investigated. The emission index (EI), global warming potential (GWP) rate, global warming potential index (GWPI), environmental impact (EnI) rate, environmental impact index (EnII), environmental damage cost (EDC) rate, and environmental damage cost index (EDCI) of the exhaust emissions of APUs are computed. The GTCP36-300 model APU has the lowest total emission rate (TER) with 1.333 kg/h, the GTC85-129 model APU has the maximum total environmental index (TEI) by 24.719 g/kg-fuel, the GTCP36-300 model APU has the best total global warming potential value with 2709.176 kg/h CO 2_eqv , the TSCP700 model APU has the worst global warming potential index rate as 52.481 kg/kWh CO 2_eqv , the best total environmental damage cost rate is calculated to be 3.717 €/h for GTC85-72 model APU, the TSCP700 model APU has the highest environmental damage cost index with 0.130 €/kWh, the maximum total environmental impact is computed to be 5656.378 mPts/h for GTCP660 model APU, and the best total environmental impact index is determined for the GTC85-72 model APU.