Aromatic and Linear Hydrocarbon Concentration Measurements in a Non-Premixed Flame

Abstract

Temperature and the concentrations of several major species, twenty one hydrocarbon intermediates ranging in size from C2H2 to C12H10, and soot were measured in an axisymmetric,atmospheric-pressure, laminar, coflowing methane/air non-premixed flame. Gas samples were extracted from the flame with a quartz microprobe and analyzed on-line with single-photon photoionization mass spectrometry. Horizontal profiles were obtained with millimeter spatial resolution at six heights above the burner surface that spanned the soot-containing portion of the flame. The flame contained numerous acetylenic species, benzene, many substituted benzenes, and several two or three-ring compounds at concentrations exceeding one part per-million. The most abundant intermediate hydrocarbons were acetylene, then alleneand/or propyne and benzene.The maximum concentrations of most linear hydrocarbons stayed roughly constant at different heights, whereas polyacetylenes and aromatics accumulated with increasing height, with larger or mo...