Characterization of black carbon particles generated by a propane-fueled miniature inverted soot generator

Abstract

The miniature inverted soot generator is a novel soot particle generator, capable of producing black carbon (BC) particles with a wide range of properties. The main advantages of this device are its portability, simplicity, low fuel consumption, and relatively low cost compared to other soot generators. In this study, the performance of the miniature inverted soot generator was evaluated using propane as the fuel over a range of air and fuel flow rates. The stability and repeatability of the soot generator to produce BC particles of controlled size distribution, and number and mass concentration was demonstrated. Furthermore, optical absorption, single scattering albedo (SSA), and elemental carbon (EC) and organic carbon (OC) concentrations of the generated particles were measured. When fueled with propane, the miniature inverted soot generator was capable of repeatedly generating particles with average mode mobility diameter ranging from 140 nm to 200 nm, number concentrations ∼4 × 106–∼2.7 × 107 #/cm3, and mass concentrations ∼8–∼140 mg/m3. For many of the investigated operating conditions, the elemental to total carbon ratio (EC/TC) of the generated soot particles was greater than 90%. The mass absorption cross section of generated particles ranged from 3 to 5 m2/g at a wavelength of 870 nm. The results obtained from this study indicate that the miniature inverted soot generator is ideal for producing BC particles with high EC fraction, which can be used as calibration aerosol for BC diagnostic instruments.