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Influence of potassium chloride and other metal salts on soot formation studied using imaging LII and ELS, and TEM techniques

Simonsson, Johan LU ; Olofsson, Nils Erik LU ; Hosseinnia, Ali LU and Bengtsson, Per Erik LU (2018) In Combustion and Flame 190. p.188-200
Abstract

An experimental investigation has been performed where the influence of metal salts on soot formation has been studied. By combining two-dimensional laser-induced incandescence (LII) and elastic light scattering (ELS), two-dimensional information could be obtained on soot properties in the flames. For these studies, seven metal salts (NaCl, MgCl2, AlCl3, KCl, CaCl2, FeCl3 and ZnCl2) were dissolved in water and aspirated into a premixed ethylene/air flame. At lower flame heights, in the soot inception region, the LII signal (representing soot volume fraction) was marginally affected by all additives, whereas the ELS signal strongly decreased with increasing additive concentration for... (More)

An experimental investigation has been performed where the influence of metal salts on soot formation has been studied. By combining two-dimensional laser-induced incandescence (LII) and elastic light scattering (ELS), two-dimensional information could be obtained on soot properties in the flames. For these studies, seven metal salts (NaCl, MgCl2, AlCl3, KCl, CaCl2, FeCl3 and ZnCl2) were dissolved in water and aspirated into a premixed ethylene/air flame. At lower flame heights, in the soot inception region, the LII signal (representing soot volume fraction) was marginally affected by all additives, whereas the ELS signal strongly decreased with increasing additive concentration for the alkali salts. At higher heights, in the soot growth region, the soot volume fractions were lowered for the addition of potassium, calcium and sodium chloride, in order of significance. Some of the salts (MgCl2, AlCl3 and FeCl3) resulted in negligible influence on LII signals and slightly higher ELS signals throughout the flames, and we relate the increased ELS signals to salt particles propagating through the flame. Main focus in our study was on the addition of potassium chloride for which several parameters were investigated. For example, soot primary particle sizes were evaluated using combined LII and ELS, showing decreasing particle sizes for increasing concentrations of potassium, in reasonable agreement with particle sizes evaluated using transmission electron microscopy. Also, CARS thermometry showed slightly higher flame temperature, ∼30 K, for the potassium-seeded flame compared to the reference flame.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Alkali metals, Elastic light scattering, Laser-induced incandescence, Particle size, Potassium, Soot
in
Combustion and Flame
volume
190
pages
188 - 200
publisher
Elsevier
external identifiers
  • scopus:85037651832
ISSN
0010-2180
DOI
10.1016/j.combustflame.2017.11.020
language
English
LU publication?
yes
id
ed10ff22-a658-4359-8cb8-dba66bc2edd8
date added to LUP
2017-12-20 14:13:50
date last changed
2018-04-01 04:30:00
@article{ed10ff22-a658-4359-8cb8-dba66bc2edd8,
  abstract     = {<p>An experimental investigation has been performed where the influence of metal salts on soot formation has been studied. By combining two-dimensional laser-induced incandescence (LII) and elastic light scattering (ELS), two-dimensional information could be obtained on soot properties in the flames. For these studies, seven metal salts (NaCl, MgCl<sub>2</sub>, AlCl<sub>3</sub>, KCl, CaCl<sub>2</sub>, FeCl<sub>3</sub> and ZnCl<sub>2</sub>) were dissolved in water and aspirated into a premixed ethylene/air flame. At lower flame heights, in the soot inception region, the LII signal (representing soot volume fraction) was marginally affected by all additives, whereas the ELS signal strongly decreased with increasing additive concentration for the alkali salts. At higher heights, in the soot growth region, the soot volume fractions were lowered for the addition of potassium, calcium and sodium chloride, in order of significance. Some of the salts (MgCl<sub>2</sub>, AlCl<sub>3</sub> and FeCl<sub>3</sub>) resulted in negligible influence on LII signals and slightly higher ELS signals throughout the flames, and we relate the increased ELS signals to salt particles propagating through the flame. Main focus in our study was on the addition of potassium chloride for which several parameters were investigated. For example, soot primary particle sizes were evaluated using combined LII and ELS, showing decreasing particle sizes for increasing concentrations of potassium, in reasonable agreement with particle sizes evaluated using transmission electron microscopy. Also, CARS thermometry showed slightly higher flame temperature, ∼30 K, for the potassium-seeded flame compared to the reference flame.</p>},
  author       = {Simonsson, Johan and Olofsson, Nils Erik and Hosseinnia, Ali and Bengtsson, Per Erik},
  issn         = {0010-2180},
  keyword      = {Alkali metals,Elastic light scattering,Laser-induced incandescence,Particle size,Potassium,Soot},
  language     = {eng},
  pages        = {188--200},
  publisher    = {Elsevier},
  series       = {Combustion and Flame},
  title        = {Influence of potassium chloride and other metal salts on soot formation studied using imaging LII and ELS, and TEM techniques},
  url          = {http://dx.doi.org/10.1016/j.combustflame.2017.11.020},
  volume       = {190},
  year         = {2018},
}