Combustion characteristics of butanol-Jet A-1 fuel blends in a swirl-stabilized combustor under the influence of preheated swirling air

Biofuels are carbon-neutral alternative fuels, which have emerged as an important source of energy for the aviation industry to reduce greenhouse gas emissions. Butanol is considered an emerging biofuel with properties that are suited for application in gas turbine engines. It is traditionally produced through the fermentation process of biomass (acetone-butanol-ethanol fermentation). To examine the feasibility of butanol as operating fuel, the combustion characteristics of butanol and butanol/Jet A-1 blends are examined in a lab-scale swirl stabilized burner, with emphasis on the effect of preheating because of the variation of inlet air temperature during flight operation. To rich the constant air temperature to 150 degrees C, the incoming air (main air) is preheated and investigated for various equivalence ratios. Compared to neat Jet A-1, the flames of the butanol/Jet A-1 blends have shown a better effect on global emission characteristics with comparable temperature distribution on adding butanol to Jet A-1. A 50% butanol-loaded blends show a reduction of 29% CO and 24% NOx compared to neat Jet A-1 whereas 30% loading follows a similar trend, and the pollutant emission is slightly higher than the 50% blend case. Additionally, both 30% and 50% butanol blends show a comparable flame temperature distribution, which is higher than neat Jet A-1.