A comparative study on the sooting tendencies of various 1-alkene fuels in counterflow diffusion flames
KAUST DepartmentClean Combustion Research Center
Physical Sciences and Engineering (PSE) Division
Mechanical Engineering Program
Chemical and Biological Engineering Program
MetadataShow full item record
AbstractAlkenes are important components in transportation fuels, and are known to have increased sooting tendencies compared to analogous saturated hydrocarbons with the same carbon number. This work aims to understand the sooting tendencies of various 1-alkenes through experiments and numerical simulations for counterflow diffusion flames. Soot and PAH formation tendencies of 1-alkene fuels, including ethylene (C2H4), propene (C3H6), 1-butene (1-C4H8), 1-pentene (1-C5H10), 1-hexene (1-C6H12) and 1-octene (1-C8H16), were experimentally studied using laser induced-incandescence (LII) and laser-induced fluorescence (LIF) techniques, respectively. From the LII results, 1-C4H8 was found to be the most sooting fuel, followed by C3H6 > 1-C5H10 > 1-C6H12 > 1-C8H16 > C2H4. The LIF data with a detection wavelength of 500 nm indicated the PAH formation tendencies followed the order of 1-C4H8 > 1-C5H10 ∼1-C6H12 > C3H6 > 1-C8H16 > C2H4, which were different from the order of sooting tendencies. Numerical simulations with a comprehensive chemical kinetic model including PAH growth chemistry for the tested 1-alkene fuels were conducted to elucidate the aromatic formation pathways and rationalize the experimentally observed trends. The numerical results highlighted the importance of intermediate species with odd carbon numbers in aromatic species formation, such as propargyl, allyl, cyclopentadienyl and indenyl radicals. Their concentration differences, which could be traced back to the parent fuel molecules through rate of production analysis, rationalize the experimentally observed differences in soot and PAH formation tendencies.
CitationWang Y, Park S, Sarathy SM, Chung SH (2018) A comparative study on the sooting tendencies of various 1-alkene fuels in counterflow diffusion flames. Combustion and Flame 192: 71–85. Available: http://dx.doi.org/10.1016/j.combustflame.2018.01.033.
SponsorsThis work was supported by the National Natural Science Foundation of China (51606136), the competitive research funding and the Clean Combustion Research Center of KAUST, and the Saudi Aramco R&DC under the FUELCOM research program.
JournalCombustion and Flame