Abstract
Electrodeless microwave plasmas were produced in nitrogen-oxygen mixtures at atmospheric pressure to investigate the formation of nitrogen oxides (NO x ) from the plasma. The oxygen content in the mixtures is varied in the range of 1%-3%, and the total flowrate is varied in the range of 25-45 slpm while the microwave power is fixed at 2 kW. The rotational and vibrational temperatures of the plasma are measured based on plasma optical emission spectroscopy, and the amount of NO x is measured using a NO x analyzer far downstream from the plasma. The temperatures at the plasma region reach ∼6700 K, and little difference is observed between the rotational and vibrational temperatures as a result of fast vibrational-translational relaxation. Moreover, these temperatures are found to be independent of the flowrate. As the flowrate decreases and the oxygen content in the mixture increases, the level of NO x is increased from 1612 ppm to 9380 ppm. For detailed investigation, plasma kinetic simulations considering trans-rotational, vibrational, and electron temperatures separately are developed and conducted for the plasma region. The level of NO x from the kinetic simulations is found to be considerably smaller than that measured. As the equilibrium mole fraction of NO x is the highest at a temperature of 3120 ± 100 K, with the variation attributable to the composition of species, significant production of NO x is expected to occur at the post-plasma region when the plasma stream is quenched by mixing with the surrounding flow.
| Original language | English |
|---|---|
| Article number | 083303 |
| Journal | Journal of Applied Physics |
| Volume | 122 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2017 Aug 28 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Formation of nitrogen oxides from atmospheric electrodeless microwave plasmas in nitrogen-oxygen mixtures. / Lee, Jungwun; Sun, Hojoong; Im, Seong Kyun; Soo Bak, Moon.
In: Journal of Applied Physics, Vol. 122, No. 8, 083303, 28.08.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Formation of nitrogen oxides from atmospheric electrodeless microwave plasmas in nitrogen-oxygen mixtures
AU - Lee, Jungwun
AU - Sun, Hojoong
AU - Im, Seong Kyun
AU - Soo Bak, Moon
PY - 2017/8/28
Y1 - 2017/8/28
N2 - Electrodeless microwave plasmas were produced in nitrogen-oxygen mixtures at atmospheric pressure to investigate the formation of nitrogen oxides (NO x ) from the plasma. The oxygen content in the mixtures is varied in the range of 1%-3%, and the total flowrate is varied in the range of 25-45 slpm while the microwave power is fixed at 2 kW. The rotational and vibrational temperatures of the plasma are measured based on plasma optical emission spectroscopy, and the amount of NO x is measured using a NO x analyzer far downstream from the plasma. The temperatures at the plasma region reach ∼6700 K, and little difference is observed between the rotational and vibrational temperatures as a result of fast vibrational-translational relaxation. Moreover, these temperatures are found to be independent of the flowrate. As the flowrate decreases and the oxygen content in the mixture increases, the level of NO x is increased from 1612 ppm to 9380 ppm. For detailed investigation, plasma kinetic simulations considering trans-rotational, vibrational, and electron temperatures separately are developed and conducted for the plasma region. The level of NO x from the kinetic simulations is found to be considerably smaller than that measured. As the equilibrium mole fraction of NO x is the highest at a temperature of 3120 ± 100 K, with the variation attributable to the composition of species, significant production of NO x is expected to occur at the post-plasma region when the plasma stream is quenched by mixing with the surrounding flow.
AB - Electrodeless microwave plasmas were produced in nitrogen-oxygen mixtures at atmospheric pressure to investigate the formation of nitrogen oxides (NO x ) from the plasma. The oxygen content in the mixtures is varied in the range of 1%-3%, and the total flowrate is varied in the range of 25-45 slpm while the microwave power is fixed at 2 kW. The rotational and vibrational temperatures of the plasma are measured based on plasma optical emission spectroscopy, and the amount of NO x is measured using a NO x analyzer far downstream from the plasma. The temperatures at the plasma region reach ∼6700 K, and little difference is observed between the rotational and vibrational temperatures as a result of fast vibrational-translational relaxation. Moreover, these temperatures are found to be independent of the flowrate. As the flowrate decreases and the oxygen content in the mixture increases, the level of NO x is increased from 1612 ppm to 9380 ppm. For detailed investigation, plasma kinetic simulations considering trans-rotational, vibrational, and electron temperatures separately are developed and conducted for the plasma region. The level of NO x from the kinetic simulations is found to be considerably smaller than that measured. As the equilibrium mole fraction of NO x is the highest at a temperature of 3120 ± 100 K, with the variation attributable to the composition of species, significant production of NO x is expected to occur at the post-plasma region when the plasma stream is quenched by mixing with the surrounding flow.
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UR - http://www.scopus.com/inward/citedby.url?scp=85028551691&partnerID=8YFLogxK
U2 - 10.1063/1.4996790
DO - 10.1063/1.4996790
M3 - Article
AN - SCOPUS:85028551691
VL - 122
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 8
M1 - 083303
ER -