Influence of ethanol and OME3 on ethylene laminar premixed flames: experimental and numerical study

The urgent transition from fossil fuels to sustainable alternatives has intensified interest in oxygenated fuels, whose inherent oxygen content alters gas-phase chemistry and suppresses the formation of soot precursors and particulate matter (PM) in internal combustion engines. Among these, ethanol (EtOH) and oxymethylene ether-3 (OME₃) have emerged as promising candidates for lowering soot and Diesel Particulate Matter (DPM) emissions. Although oxygenated fuels are known to reduce particulate mass emissions, their impact on ultrafine particles (UFPs) and nanoparticles (NPs) – which pose significant health risks – remains ambiguous, with literature showing conflicting results. The physicochemical properties and functional groups of oxygenated compounds, beyond mere oxygen content, play a crucial role in shaping particle formation dynamics and toxicity. This study investigates ethylene (C2H4)/air premixed flames doped with EtOH or OME3. These oxygenated fuels, accounting for 20% (α) of the total carbon fed, were introduced into the fuel stream in flames with equivalence ratios (Φ) ranging from 2.01 to 2.46, encompassing near- and highly sooting conditions. A combined experimental and numerical approach is employed to assess variations in soot and NP emissions, offering new insights into the influence of oxygenated fuel structure on combustion and particulate behavior.