Clean combustion in gas turbine engines using Butyl Nonanoate biofuel

Abstract

Developing new and renewable biofuels for ultra-low emission gas turbine combustors is much desired to secure future power needs. Several fuels are being developed to replace fossil fuels with minimal carbon footprint and pollutants emission. Ease of transition between fossil fuels and biofuels is also desired for fuel flexibility in engine operation. In this paper, the performance of Butyl Nonanoate biofuel is evaluated and compared to both Hydrogenated Renewable Jet (HRJ) fuel and JP-8. The atomization characteristics are examined using Phase Doppler Particle Analyzer (PDPA) for favorable condition of fuel introduction to the combustor. The Biofuel provided 10–15% larger size droplets compared to JP-8 for a given atomizer and operational pressure. The combustion behavior of biofuel was also examined in a swirling colorless distributed combustor with focus on pollutants emission under high intensity simulated gas turbine conditions. The liquid fuels were directly fed into the path of the air stream prior to combustion without using any atomizer or spray device. The biofuel provided 6 PPM of NO and 35 PPM of CO at an energy release intensity of 27MW/m3-atm at 0.6 equivalence ratio. The recorded emissions are about 15% lower as compared to JP-8 for equivalence ratio higher than 0.65. For lower equivalence ratios, NO emissions were identical. The Butyl Nonanoate biofuel also exhibited lower NO emissions than HRJ biofuel. The CO emissions were lower with Butyl Nonanoate as compared to JP-8 (this is in contrast to HRJ biofuel which showed an increase in CO compared to JP-8). The examined biofuel did not show any instability with smooth transition between different fuels. These results provide promising behavior of Butyl Nonanoate biofuel for use in future energy needs without any modifications to the combustor injectors, while maintaining high performance.