The effects of molecular structure on soot formation II. Diffusion flames

Abstract Soot thresholds, in the form of flame heights and fuel mass consumption rates at the smoke points, have been measured in atmospheric pressure, laminar diffusion flames of 42 pure hydrocarbons using a wick-fed burner. The smoke point fuel consumption rates were converted into threshold soot indices, TSIs, and compared with fuel structural parameters and with previous data from the literature. Averaged TSI values are given for 103 fuels. Soot particle emission temperatures and line-of-sight averaged soot volume fractions were measured at half the total smoke point flame heights, the location at which the soot concentration maximizes. All of the soot emission temperatures were between 1450 and 1550K, with aromatic fuels exhibiting the highest temperatures. Maximum soot volume fractions ranged from 2 to 11 × 10−6, with aromatic fuels producing the highest total soot concentrations.