Experimental and kinetic modeling study of n-pentane oxidation at 10 atm, Detection of complex low-temperature products by Q-Exactive Orbitrap

Renewable feedstock such as biomass derivatives (hemicellulose, furfural) can be used to produce synthetic fuels, e.g., n-pentane, of interest for enhancing performance diesel and gasoline engines. Whereas numerous studies n-pentane have been published, its low temperature oxidation is not fully characterized even recent kinetic models do incorporate extended pathways which still need observed n-pentane. In this context, a continuous flow fused-silica jet-stirred reactor (JSR) was studying the 2500 ppm at 520?800 K, 10 atm (representative piston engines operating conditions), an equivalence ratio 0.5, residence time 1.5 s. Oxidation products were analyzed in gas phase using chromatography (thermal conductivity, TCD flame ionization, FID), Fourier-transform infrared spectrometry (FTIR), electron impact ionization-quadrupole mass (EI-qMS). Gaseous also dissolved acetonitrile characterization injection analysis (FIA), high-pressure ultra-high-pressure liquid (HPLC UHPLC) coupled atmospheric pressure chemical ionization (APCI) Q-Exactive®-Orbitrap high resolution (HRMS). This allowed detecting lower higher oxygenated molecules methyl vinyl ketone (MVK) 2,5-dihydrofuran (C4H6O), 2-butanone (C4H8O), 3-pentene-2-one (C5H8O), pentanediones (C5H8O2), cyclic ethers pentanones (C5H10O), C3?C5 alkylhydroperoxides (C3H8O2, C4H10O2, C5H12O2), C2?C5 alkenylhydroperoxides (C2H4O2, C3H6O2, C4H8O2, C5H10O2), keto-hydroperoxides (C3H6O3, C4H8O3, C5H10O3), highly (C5H8O4, C5H12O4, C5H10O4, C5H10O5, C5H10O7) produced through multiply O2 addition on fuel's radicals internal H-shifts. Among these 15 had reported before. Simulation present experiments showed discrepancies between experimental results predictions.