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Optical investigation of gas-phase KCl/KOH sulfation in post flame conditions

Weng, Wubin LU ; Chen, Shuang LU ; Wu, Hao; Glarborg, Peter and Li, Zhongshan LU (2018) In Fuel 224. p.461-468
Abstract

A counter-flow reactor setup was designed to investigate the gas-phase sulfation and homogeneous nucleation of potassium salts. Gaseous KOH and KCl were introduced into the post-flame zone of a laminar flat flame. The hot flame products mixed in the counter-flow with cold N2, with or without addition of SO2. The aerosols formed in the flow were detected through Mie scattering of a 355 nm laser beam. The temperature distribution of the flow was measured by molecular Rayleigh scattering thermometry. From the temperature where nucleation occurred, it was possible to identify the aerosols formed. Depending on the potassium speciation in the inlet and the presence of SO2, they consisted of... (More)

A counter-flow reactor setup was designed to investigate the gas-phase sulfation and homogeneous nucleation of potassium salts. Gaseous KOH and KCl were introduced into the post-flame zone of a laminar flat flame. The hot flame products mixed in the counter-flow with cold N2, with or without addition of SO2. The aerosols formed in the flow were detected through Mie scattering of a 355 nm laser beam. The temperature distribution of the flow was measured by molecular Rayleigh scattering thermometry. From the temperature where nucleation occurred, it was possible to identify the aerosols formed. Depending on the potassium speciation in the inlet and the presence of SO2, they consisted of K2SO4, KCl, or K2CO3, respectively. The experiments showed that KOH was sulphated more readily than KCl, resulting in larger quantities of aerosols. The sulfation process in the counter-flow setup was simulated using a chemical kinetic model including a detailed subset for the Cl/S/K chemistry. Similar to the experimental results, much more potassium sulfate was predicted when seeding KOH compared to seeding KCl. For both KOH and KCl, sulfation was predicted to occur primarily through the reactions among atomic K, O2 and SO2, forming KHSO4 and K2SO4. The higher propensity for sulfation of KOH compared to KCl was mostly attributed to the lower thermal stability of KOH, facilitating formation of atomic K. According to the model, sulfation also happened through SO3, especially for KCl (KCl → KSO3Cl → K2SO4).

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aerosol, Counter-flow, Potassium chloride, Potassium hydroxide, Sulfation
in
Fuel
volume
224
pages
8 pages
publisher
Elsevier
external identifiers
  • scopus:85044166410
ISSN
0016-2361
DOI
10.1016/j.fuel.2018.03.095
language
English
LU publication?
yes
id
d7b0b581-0f9f-40fc-9d45-d5a4f9c78cc4
date added to LUP
2018-04-03 12:23:46
date last changed
2019-04-21 05:13:04
@article{d7b0b581-0f9f-40fc-9d45-d5a4f9c78cc4,
  abstract     = {<p>A counter-flow reactor setup was designed to investigate the gas-phase sulfation and homogeneous nucleation of potassium salts. Gaseous KOH and KCl were introduced into the post-flame zone of a laminar flat flame. The hot flame products mixed in the counter-flow with cold N<sub>2</sub>, with or without addition of SO<sub>2</sub>. The aerosols formed in the flow were detected through Mie scattering of a 355 nm laser beam. The temperature distribution of the flow was measured by molecular Rayleigh scattering thermometry. From the temperature where nucleation occurred, it was possible to identify the aerosols formed. Depending on the potassium speciation in the inlet and the presence of SO<sub>2</sub>, they consisted of K<sub>2</sub>SO<sub>4</sub>, KCl, or K<sub>2</sub>CO<sub>3</sub>, respectively. The experiments showed that KOH was sulphated more readily than KCl, resulting in larger quantities of aerosols. The sulfation process in the counter-flow setup was simulated using a chemical kinetic model including a detailed subset for the Cl/S/K chemistry. Similar to the experimental results, much more potassium sulfate was predicted when seeding KOH compared to seeding KCl. For both KOH and KCl, sulfation was predicted to occur primarily through the reactions among atomic K, O<sub>2</sub> and SO<sub>2</sub>, forming KHSO<sub>4</sub> and K<sub>2</sub>SO<sub>4</sub>. The higher propensity for sulfation of KOH compared to KCl was mostly attributed to the lower thermal stability of KOH, facilitating formation of atomic K. According to the model, sulfation also happened through SO<sub>3</sub>, especially for KCl (KCl → KSO<sub>3</sub>Cl → K<sub>2</sub>SO<sub>4</sub>).</p>},
  author       = {Weng, Wubin and Chen, Shuang and Wu, Hao and Glarborg, Peter and Li, Zhongshan},
  issn         = {0016-2361},
  keyword      = {Aerosol,Counter-flow,Potassium chloride,Potassium hydroxide,Sulfation},
  language     = {eng},
  month        = {07},
  pages        = {461--468},
  publisher    = {Elsevier},
  series       = {Fuel},
  title        = {Optical investigation of gas-phase KCl/KOH sulfation in post flame conditions},
  url          = {http://dx.doi.org/10.1016/j.fuel.2018.03.095},
  volume       = {224},
  year         = {2018},
}