Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4764520 | Combustion and Flame | 2017 | 13 Pages |
Abstract
This paper is concerned with the investigation of the chemical structure of a low-pressure, fuel-rich (ɸ = 1.8) premixed laminar flame fueled with 2-methyl-2-butene employing flame-sampling molecular-beam mass spectrometry with vacuum-ultraviolet single-photon ionization. Partially isomer-resolved mole fraction profiles can be explained by a decomposition scheme based on hydrogen abstraction and addition reactions. The presence of 9 allylic CH bonds compared to only one vinylic CH bond is the key feature that governs the fuel consumption and subsequent hydrocarbon growth reactions. Compared to other alkenes, including e.g., 1-butene, 2-butene, and iso-butene (Schenk et al., 2013), 2-methyl-2-butene shows a remarkable tendency to form soot precursor molecules such as toluene. In particular, experimental evidence is provided here that toluene, o-xylene, and styrene can be a starting point for PAH formation, thus serving as first aromatic rings besides benzene. The formation of toluene, o-xylene, and styrene can be traced back to the reactions of the resonantly stabilized C4H5 [âCH2CCCH3 and CH2CHâCCH2] radicals and the C5H7 [CH2C(CH3)âCCH2] radicals that are readily formed through fuel-specific decomposition channels. Our experimental data in form of mole fraction profiles as a function of height above the burner for a mass range from 2 to 210 u can serve as reliable validation targets for model development. A preliminary comparison to the model of Westbrook et al. [1] that was optimized to capture ignition delay times and the low-temperature oxidation regime, shows promising elements already for the initial fuel consumption.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Lena Ruwe, Kai Moshammer, Nils Hansen, Katharina Kohse-Höinghaus,