Influence of conventional and alternative jet fuel composition on gaseous, particulate and unregulated emissions in a gas turbine combustion chamber

The aviation industry’s transition towards sustainable aviation fuels (SAFs) requires a fundamental understanding of how specific type of hydrocarbon groups influence gas turbine combustion kinetics, stability and exhaust speciation. Despite significant progress, notable research gaps persist regarding the combustion and operational characteristics of 100% synthetic fuels, particularly synthetic paraffinic kerosene (SPK) and synthetic aromatic kerosene (SAK) as drop-in replacements for conventional Jet A. This study investigates the regulated emissions ( upper C upper O C O $CO$ , upper C upper O 2 C O 2 CO₂ , upper N upper O Subscript x N O x NOₓ , total unburned hydrocarbons [UHC]), particulate matter (PM) number and mass concentrations. Along with unregulated volatile organic compounds (VOCs) of conventional jet fuels (Jet A, JP 8, JP 5), synthetic pathways (alcohol to jet [ATJ], hydro processed esters and fatty acids [HEFA], SAK), and their formulated blends. Results demonstrate that highly branched isoparaffins (e.g. pure ATJ) maximise primary zone oxidation efficiency, reducing intermediate upper C upper O C O $CO$ , UHC and PM nucleation. However, their rapid oxidation kinetics and high heat of combustion generate localised thermal hot spots that significantly compromising blends with increased thermal upper N upper O Subscript x N O x NOₓ . Aromatics addition acts as a chemical heat sink, suppressing upper N upper O Subscript x N O x NOₓ formation, but exponentially increases upper C upper O C O $CO$ , UHC and PM mass through polycyclic aromatic hydrocarbon (PAH) soot precursors. Furthermore, pure HEFA and SAK result in poor combustion stability and lean blowout at lower heat release rates (HRRs). Ultimately, mid-to-high blends of SPK with SAK (8–25%) outperform conventional Jet A across aggregate emission profiles while satisfying American Society for Test