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Co-generation of hydrogen and carbon aerosol from coalbed methane surrogate using rotating gliding arc plasma

Wu, Angjian; Li, Xiaodong; Yan, Jianhua; Yang, Jian; Du, Changming; Zhu, Fengsen and Qian, Jinyuan LU (2017) In Applied Energy 195. p.67-79
Abstract

A novel atmospheric pressure non-thermal plasma, i.e., rotating gliding arc (RGA), is developed to upgrade coal bed methane (CBM) into hydrogen and carbon aerosol simultaneously. CH4 is used as a CBM surrogate. In present work, the V-I characteristics of RGA discharge in CH4 conversion are monitored with different gases (N2, Ar and CO2) as carrier gas, while the active species (such as OH, CH, CN, C2, excited molecules and ions) involved in the plasma reactions are identified by optical emission spectroscopy (OES). According to the sensitivity analysis of specific energy density (SED), the importance of operating conditions on SED sensitivity is in a sequence of CH4... (More)

A novel atmospheric pressure non-thermal plasma, i.e., rotating gliding arc (RGA), is developed to upgrade coal bed methane (CBM) into hydrogen and carbon aerosol simultaneously. CH4 is used as a CBM surrogate. In present work, the V-I characteristics of RGA discharge in CH4 conversion are monitored with different gases (N2, Ar and CO2) as carrier gas, while the active species (such as OH, CH, CN, C2, excited molecules and ions) involved in the plasma reactions are identified by optical emission spectroscopy (OES). According to the sensitivity analysis of specific energy density (SED), the importance of operating conditions on SED sensitivity is in a sequence of CH4 concentration > applied voltage > residence time. The performance of CH4 conversions are comparatively evaluated based on the variation of operating conditions. In general, the enhancement of applied voltage and residence time effectively increases the CH4 conversions, selectivity of hydrogen, as well as the energy efficiency, while the augment of CH4 concentration has a negative effect in contrast. The carbon aerosol obtained in CH4/N2 and CH4/Ar discharge are comparatively investigated. Transparent crumped-like graphene sheets and spherical nanostructure carbon are observed in both obtained carbon aerosol, with relative high ID/IG ratios (∼0.62) indicated in Raman spectroscopy. High C/O ratios (>14) are obtained in the XPS survey spectra, with the intensity ratios of sp2 C[dbnd]C/sp3 C-C occupy about 80%. However, the BET surface area of carbon obtained from CH4/N2 is almost 3 times larger than that from CH4/Ar discharge. In addition, super hydrophobic and oleophilic properties are observed in both carbon samples. The contact angles of water droplets are above 130°, while the contact angle of oil is less than 4°.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Carbon aerosol, Characterization, Co-generation, Coalbed methane, Hydrogen, Rotating gliding arc (RGA)
in
Applied Energy
volume
195
pages
13 pages
publisher
Elsevier
external identifiers
  • scopus:85015650474
  • wos:000400227000006
ISSN
0306-2619
DOI
10.1016/j.apenergy.2017.03.043
language
English
LU publication?
yes
id
c29e8e3d-ecb3-4504-921d-30c8eb04b191
date added to LUP
2017-06-24 01:16:42
date last changed
2018-01-07 12:08:47
@article{c29e8e3d-ecb3-4504-921d-30c8eb04b191,
  abstract     = {<p>A novel atmospheric pressure non-thermal plasma, i.e., rotating gliding arc (RGA), is developed to upgrade coal bed methane (CBM) into hydrogen and carbon aerosol simultaneously. CH<sub>4</sub> is used as a CBM surrogate. In present work, the V-I characteristics of RGA discharge in CH<sub>4</sub> conversion are monitored with different gases (N<sub>2</sub>, Ar and CO<sub>2</sub>) as carrier gas, while the active species (such as OH, CH, CN, C<sub>2</sub>, excited molecules and ions) involved in the plasma reactions are identified by optical emission spectroscopy (OES). According to the sensitivity analysis of specific energy density (SED), the importance of operating conditions on SED sensitivity is in a sequence of CH<sub>4</sub> concentration &gt; applied voltage &gt; residence time. The performance of CH<sub>4</sub> conversions are comparatively evaluated based on the variation of operating conditions. In general, the enhancement of applied voltage and residence time effectively increases the CH<sub>4</sub> conversions, selectivity of hydrogen, as well as the energy efficiency, while the augment of CH<sub>4</sub> concentration has a negative effect in contrast. The carbon aerosol obtained in CH<sub>4</sub>/N<sub>2</sub> and CH<sub>4</sub>/Ar discharge are comparatively investigated. Transparent crumped-like graphene sheets and spherical nanostructure carbon are observed in both obtained carbon aerosol, with relative high I<sub>D</sub>/I<sub>G</sub> ratios (∼0.62) indicated in Raman spectroscopy. High C/O ratios (&gt;14) are obtained in the XPS survey spectra, with the intensity ratios of sp<sup>2</sup> C[dbnd]C/sp<sup>3</sup> C-C occupy about 80%. However, the BET surface area of carbon obtained from CH<sub>4</sub>/N<sub>2</sub> is almost 3 times larger than that from CH<sub>4</sub>/Ar discharge. In addition, super hydrophobic and oleophilic properties are observed in both carbon samples. The contact angles of water droplets are above 130°, while the contact angle of oil is less than 4°.</p>},
  author       = {Wu, Angjian and Li, Xiaodong and Yan, Jianhua and Yang, Jian and Du, Changming and Zhu, Fengsen and Qian, Jinyuan},
  issn         = {0306-2619},
  keyword      = {Carbon aerosol,Characterization,Co-generation,Coalbed methane,Hydrogen,Rotating gliding arc (RGA)},
  language     = {eng},
  month        = {06},
  pages        = {67--79},
  publisher    = {Elsevier},
  series       = {Applied Energy},
  title        = {Co-generation of hydrogen and carbon aerosol from coalbed methane surrogate using rotating gliding arc plasma},
  url          = {http://dx.doi.org/10.1016/j.apenergy.2017.03.043},
  volume       = {195},
  year         = {2017},
}