Combustion Products of Petroleum Jet Fuel, a Fischer-Tropsch Synthetic Fuel, and a Biomass Fatty Acid Methyl Ester Fuel for a Gas Turbine Engine

• Published in: Combustion science and technology Vol. 183; no. 10; pp. 1039 - 1068
• Main Authors: Timko, Michael T., Herndon, Scott C., de la Rosa Blanco, Elena, Wood, Ezra C., Yu, Zhenhong, Miake-Lye, Richard C., Knighton, W. Berk, Shafer, Linda, DeWitt, Matthew J., Corporan, Edwin
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01-10-2011; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Alternative fuels; Applied sciences; Biomass; Blends; Combustion; Combustion. Flame; Crude oil; Emissions; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fischer-Tropsch process; Fuels; Gas turbine engine; Gas turbine engines; Jet fuels; Particle emission; Petroleum; Synthetic fuels; Theoretical studies. Data and constants. Metering; VOCs; Volatile organic compounds; Mixing; Gaseous fuel; Engine test; Combustion; Biomass; Flame propagation; Pollutant emission; Ester; Particle emission; Aromatic compound; Gas engine; Butene; Nitrogen oxide; Hydrocarbon; Toluene; Fuel gas; Petroleum product; Volatile organic compound; Jet fuel; Fatty acids; Emissions; Particle size distribution; Propene; Benzene; Gas turbine engine; Gas turbine; Performance; Natural gas; Alternative fuels
• ISSN: 0010-2202; 1563-521X
• DOI: 10.1080/00102202.2011.581717

We report combustion emissions data for several alternatives to petroleum based Jet A jet fuel, including a natural gas-derived Fischer-Tropsch (FT) synthetic fuel; a 50/50 blend of the FT synthetic fuel with Jet A-1; a 20/80 blend of a fatty acid methyl ester (FAME) with jet fuel; and a 40/60 blend of FAME with jet fuel. The chief distinguishing features of the alternative fuels are reduced (for blends) or negligible (for pure fuels) aromatic content and increased oxygen content (for FAME blends). A CFM International CFM56-7 gas turbine engine was the test engine, and we measured NO
X
, CO, speciated volatile organic compounds (including oxygenates, olefins, and aromatic compounds), and nonvolatile particle size distribution, number, and mass emissions. We developed several new methods that account for fuel energy content and used the new methods to evaluate potential fuel effects on emissions performance. Our results are categorized as follows: (1) regulated pollutant emissions, CO, and NO
X
; (2) volatile organic compound emissions speciation; and (3) particle emissions. Replacing all or part of the petroleum jet fuel with either FAME or FT fuel reduces NO
X
emissions and may reduce CO emissions. Combustion of FT fuel and fuel blends increases selectivities and in some cases yields of oxygenates and some hydrocarbon volatile organic compound emissions relative to petroleum jet fuel. Combustion of FAME fuel increases propene and butene emissions, but despite its oxygen content does not strongly affect oxygenate emissions. Replacing petroleum jet fuel with zero aromatic alternatives decreases the emissions of aromatic hydrocarbons. The fuel effects become more pronounced as the size of the aromatic molecule increases (e.g., toluene is reduced more strongly than benzene). Particle emissions are decreased in particle size, number density, and total mass when petroleum jet fuel is replaced with the zero aromatic fuels. The effects of fuel composition on particle emissions are most pronounced at lower power conditions, i.e., when combustion temperature and pressure are lower, and less efficient mixing may lead to locally higher fuel/air ratios than are present at higher power.