Oxidation of n-Heptane in a Premixed Laminar Flame

Abstract

A premixed laminar n-heptane/air flame (1 atm and ) 1. 0 ( 0.05) was investigated experimentally (using on-line GC/MS) and computationally. Ethene, propene, 1-butene, 1-pentene, 1-hexene, and 1-heptene showed broad peaks with maxima at a distance around 1000 µm from the burner. Methane, ethane, and propane showed more narrow peaks and maxima around 1075 µm. The following compounds with their maxima were found (mol %): ethene (0.99), methane (0.069), propene (0.127), ethyne (0.103), ethane (0.080), 1-butene (0.040), 1-pentene (0.021), and 1,3-butadiene (0.014). Concentrations of less than 0.01 mol % were detected for the components 1-heptene, propyne, propadiene, methanol, and acetaldehyde. The flame was modeled using the semiempirical mechanism by Held et al. 1 The model produced peaks of the organic intermediates at about 400-500 µm. Important measured species not present in the mechanism were propane, propyne, methanol, isobutene, 2-butene, and 1-heptene. The computed maxima of 1-butene, 1,3-butadiene, and 1-pentene were higher than the experimental maxima by a factor of about 2, 2, and 3, respectively. The model gives very similar results for two different pressures, 1 and 0.06 atm, except for a common scaling factor.

Effects of oxygenate concentration on species mole fractions in premixed -heptane flames

“…The oxidation of n-heptane has been studied using several experimental techniques, including shock tubes [2,3], jet stirred reactors [4,5], premixed [6][7][8][9], and diffusion flames [10,11].…”

“…Atmospheric pressure, premixed, flat flames of n-heptane were investigated using unheated microprobe sampling and GC/MS both by Bakali et al [8] and Ingemarsson et al [9] at equivalence ratios of 1.9 and 1.0, respectively. Their studies were limited to low-molecularweight species only.…”

Effects of equivalence ratio on species and soot concentrations in premixed n-heptane flames

“…Doute et al [6] obtained the mole fraction profiles of stable species and free radicals in low-pressure (6.0 kPa), premixed laminar nheptane/oxygen/Ar flames using molecular beam mass spectrometry. Atmospheric-pressure, premixed laminar n-heptane/air flame at stoichiometric composition has recently been studied experimentally and computationally by Ingemarsson et al [7]. They detected about 30 stable organic species using online GC/MS system.…”

Artificial neural network predictions of polycyclic aromatic hydrocarbon formation in premixed n-heptane flames

“…The concentration profiles of stable species and free radicals in low-pressure (6.0 kPa), laminar, premixed n-heptane flames have been reported by Doute et al [14] for equivalence ratios of 0.7 ≤ ϕ ≤ 2.0 using molecular beam mass spectrometry. El Bakali et al [15] and Ingemarsson et al [16] have carried out quartz microprobe sampling and GC/MS analysis for the lowmolecular-weight species (e.g., up to benzene) concentration profiles in atmospheric pressure, premixed n-heptane flames at equivalence ratios of 1.9 and 1.0, respectively. Recently, we [17] have investigated the PAH formation in fuel rich (ϕ = 1.97 and 2.10) laminar, premixed n-heptane flames.…”