Resolving combustion and molecular-level organic particles of a novel staged-combustor under operational modes burning SAF compared to kerosene

Global aviation mandates the decarbonization goal intensively to attain carbon neutrality. Herein, sustainable aviation fuel (SAF) becomes a key solution, whereas the research on organic particulate matter (PM) from SAF combustion remains scarce. This study mainly addresses the particulate intermediate/semi-volatile organic compounds (I/SVOCs) emitted from a dual-stage aero-engine combustor by burning SAF compared to RP-3 kerosene under varied combustor powers (5%-100%) and preheating temperatures (250 °C-450 °C). By utilizing Two-dimensional Gas Chromatography Coupled with Time-of-flight Mass Spectrometry (GC × GC-ToFMS) technique, molecular-level I/SVOCs (n-alkanes, n-alkyl-cyclohexanes, and PAHs) have been qualitatively and quantitatively speciated. Majorly analytical results with in-depth fundamental mechanisms illustration are provided: 1) Elevating preheating temperature from 250 °C to 450 °C suppresses I/SVOCs by over 55% remarkably, mainly attributed to promoted atomisation and prominent thermo-reactions towards intensive oxidation. 2) The combustion shifting from approach to takeoff condition could dramatically inhibit I/SVOCs by nearly 65% (at 250 °C). This is mainly because the combustion mode transitioned from diffusion mode to premixed-dominant mode, controlling particulate formation. 3) In comparison to kerosene, burning SAF also reduces I/SVOCs by around 50%, attributed to compositional difference and better evaporation. More importantly, Response Surface Methodology (RSM) with Analysis of Variance (ANOVA) has been statistically adopted, and it reflects the strongly interactive effects of power and temperature on PAHs, and nonlinear effects of operational parameters on varying I/SVOCs. The RSM models successfully predict the organic particles with in-depth fundamental mechanisms resolved, demonstrating that SAF under premixed-dominant mode with intensive preheating could effectively implement pollutants control.