The influence of i-butanol addition to the chemistry of premixed 1,3-butadiene flames

Abstract

Chemical structures of three low-pressure premixed flames of 1,3-butadiene/i-butanol mixtures with different ratios of 1,3-butadiene and i-butanol were investigated experimentally with flame-sampling molecular-beam mass spectrometry and numerically by chemically detailed modeling. Partially isomer-resolved mole fraction profiles of approximately 70 components per flame were determined using the well-established single-photon ionization technique via easily tunable synchrotron-generated vacuum-ultraviolet photons. The used chemical-kinetic reaction model is based on the work of Hansen et al. [Proc. Combust. Inst. 35 (2015) 771-778] of complementary 1,3-butadiene/n-butanol mixture flames. Within the present study, the reaction model has been significantly updated and simultaneously extended, to include the high-temperature oxidation chemistry of i-butanol. It is shown, by referring to both experimental and modeling results, that the concentration of benzene depends on the amount of 1,3-butadiene in the fuel mixture, indicating that i-butanol chemistry is not adding significantly towards aromatic ring formation. Trends in the concentration of other intermediates can also be largely predicted based on the established oxidation of 1,3-butadiene and i-butanol, thus revealing no detectible cross-linkages between the intermediate pools of the individual fuel components.