Design and Characterization of a Flame Spray Pyrolysis Apparatus to Compare Soot Emissions from Liquid Fuels

Abstract

This study investigates flame spray pyrolysis (FSP) as a simple bench-top tool for comparison of soot emissions from different liquid jet fuels. A sampling assembly is designed for soot collection and particle property analysis. Soot agglomerate size distributions and elemental to total carbon ratios (EC/TC) are measured for three liquid fuels and flame conditions with Reynolds numbers and burner equivalence ratios ranging from 6000 to 9100 and 6.7 to 13.1. Day-to-day variations in the dilution ratio resulted in up to 20% variability in the measured total agglomerate number density and mobility diameters. Geometric mean primary particle (𝑑 𝑝 ̅̅̅ ) and mobility diameter (𝑑 𝑚 ̅̅̅̅ ) values are below 21 and 113 nm, respectively, in excellent agreement with those emitted from jet engines and earlier works using FSP. EC/TC is higher than 0.8 for all flames burning Jet A1, but values as low as 0.55 are measured for soot emitted from SAF burning flames.