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Sodium and Potassium Released from Burning Particles of Brown Coal and Pine Wood in a Laminar Premixed Methane Flame Using Quantitative Laser-Induced Breakdown Spectroscopy

Hsu, Li-Jen; Alwahabi, Zeyad T.; Nathan, Graham J.; Li, Yu; Li, Zhongshan LU and Aldén, Marcus LU (2011) In Applied Spectroscopy 65(6). p.684-691
Abstract
A quantitative point measurement of total sodium ([Na](total)) and potassium ([K](total)) in the plume of a burning particle of Australian Loy Yang brown coal (23 +/- 3 mg) and of pine wood pellets (63 +/- 3 mg) was performed using laser-induced breakdown spectroscopy (LIBS) in a laminar premixed methane flame at equivalence ratios (Phi) of 1.149 and 1.336. Calibration was performed using atomic sodium or potassium generated by evaporation of droplets of sodium sulfite (Na2SO3) or potassium sulfate (K2SO4) solutions seeded into the flame. The calibration compensated for the absorption by atomic alkalis in the seeded flame, which is significant at high concentrations of solution. This allowed quantitative measurements of sodium (Na) and... (More)
A quantitative point measurement of total sodium ([Na](total)) and potassium ([K](total)) in the plume of a burning particle of Australian Loy Yang brown coal (23 +/- 3 mg) and of pine wood pellets (63 +/- 3 mg) was performed using laser-induced breakdown spectroscopy (LIBS) in a laminar premixed methane flame at equivalence ratios (Phi) of 1.149 and 1.336. Calibration was performed using atomic sodium or potassium generated by evaporation of droplets of sodium sulfite (Na2SO3) or potassium sulfate (K2SO4) solutions seeded into the flame. The calibration compensated for the absorption by atomic alkalis in the seeded flame, which is significant at high concentrations of solution. This allowed quantitative measurements of sodium (Na) and potassium (K) released into the flame during the three phases of combustion, namely devolatilization, char, and ash cooking. The [Na](total) in the plume released from the combustion of pine wood pellets during the devolatilization was found to reach up to 13 ppm. The maximum concentration of total sodium ([Na](total)(max)) and potassium ([K](total)(max)) released during the char phase of burning coal particles for Phi = 1.149 was found to be 9.27 and 5.90 ppm, respectively. The [Na](total)(max) and [K](total)(max) released during the char phase of burning wood particles for Phi = 1.149 was found to be 15.1 and 45.3 ppm, respectively. For the case of Phi = 1.336, the [Na](total)(max) and [K](total)(max) were found to be 13.9 and 6.67 ppm during the char phase from burning coal particles, respectively, and 21.1 and 39.7 ppm, respectively, from burning wood particles. The concentration of alkali species was higher during the ash phase. The limit of detection (LOD) of sodium and potassium with LIBS in the present arrangement was estimated to be 29 and 72 ppb, respectively. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Brown coal, Pine wood, Alkali elements, Laser-induced breakdown, spectroscopy, Quantitative LIBS, Laminar premixed methane flame
in
Applied Spectroscopy
volume
65
issue
6
pages
684 - 691
publisher
Society for Applied Spectroscopy
external identifiers
  • wos:000291232100016
  • scopus:79958694856
ISSN
1943-3530
DOI
10.1366/10-06108
language
English
LU publication?
yes
id
2aea0d17-30c5-490e-9b04-d6e20f16f1c8 (old id 1985630)
date added to LUP
2011-07-06 12:15:25
date last changed
2017-08-13 03:08:21
@article{2aea0d17-30c5-490e-9b04-d6e20f16f1c8,
  abstract     = {A quantitative point measurement of total sodium ([Na](total)) and potassium ([K](total)) in the plume of a burning particle of Australian Loy Yang brown coal (23 +/- 3 mg) and of pine wood pellets (63 +/- 3 mg) was performed using laser-induced breakdown spectroscopy (LIBS) in a laminar premixed methane flame at equivalence ratios (Phi) of 1.149 and 1.336. Calibration was performed using atomic sodium or potassium generated by evaporation of droplets of sodium sulfite (Na2SO3) or potassium sulfate (K2SO4) solutions seeded into the flame. The calibration compensated for the absorption by atomic alkalis in the seeded flame, which is significant at high concentrations of solution. This allowed quantitative measurements of sodium (Na) and potassium (K) released into the flame during the three phases of combustion, namely devolatilization, char, and ash cooking. The [Na](total) in the plume released from the combustion of pine wood pellets during the devolatilization was found to reach up to 13 ppm. The maximum concentration of total sodium ([Na](total)(max)) and potassium ([K](total)(max)) released during the char phase of burning coal particles for Phi = 1.149 was found to be 9.27 and 5.90 ppm, respectively. The [Na](total)(max) and [K](total)(max) released during the char phase of burning wood particles for Phi = 1.149 was found to be 15.1 and 45.3 ppm, respectively. For the case of Phi = 1.336, the [Na](total)(max) and [K](total)(max) were found to be 13.9 and 6.67 ppm during the char phase from burning coal particles, respectively, and 21.1 and 39.7 ppm, respectively, from burning wood particles. The concentration of alkali species was higher during the ash phase. The limit of detection (LOD) of sodium and potassium with LIBS in the present arrangement was estimated to be 29 and 72 ppb, respectively.},
  author       = {Hsu, Li-Jen and Alwahabi, Zeyad T. and Nathan, Graham J. and Li, Yu and Li, Zhongshan and Aldén, Marcus},
  issn         = {1943-3530},
  keyword      = {Brown coal,Pine wood,Alkali elements,Laser-induced breakdown,spectroscopy,Quantitative LIBS,Laminar premixed methane flame},
  language     = {eng},
  number       = {6},
  pages        = {684--691},
  publisher    = {Society for Applied Spectroscopy},
  series       = {Applied Spectroscopy},
  title        = {Sodium and Potassium Released from Burning Particles of Brown Coal and Pine Wood in a Laminar Premixed Methane Flame Using Quantitative Laser-Induced Breakdown Spectroscopy},
  url          = {http://dx.doi.org/10.1366/10-06108},
  volume       = {65},
  year         = {2011},
}