Soot Precursor Formation in Low-Temerature Flat-Burner Flames

Abstract

The formation of polycyclic aromatic hydrocarbons (PAHs) and ion has been studied on the laminar, diethyl-ether/air premixed low-temperature flames under atmospheric pressure and the equivalence ratio ranging from 3.0 to 6.0, to obtain an advanced knowledge of soot formation processes. A flat-burner is enclosed by a concentric quatz tube to prevent infiltration of surrounding air. Ion formation is recognized to be related to soot precursor formation. The ion current has been measured using an ionization gap. A liquid chromatograph with a fluorescence detector was applied to separate and determine PAHs contained in specimens sampled from low-temperature flames. PAHs was obtained by microwave extraction of soluble organic fraction (SOF) on silica glass filters. It is indicated a possibility that the ion is generated from the exited oxygen molecules and acetylene generation due to the interrelation between ion current and light emission. It has also been found that the PAHs first appears during the cool flame period.