Title
Modeling plasma-based <tex>$CO_{2}$</tex> conversion : crucial role of the dissociation cross sectionModeling plasma-based <tex>$CO_{2}$</tex> conversion : crucial role of the dissociation cross section
Author
Faculty/Department
Faculty of Sciences. Chemistry
Research group
Plasma, laser ablation and surface modeling - Antwerp (PLASMANT)
Publication type
article
Publication
Bristol :Institute of Physics,
Subject
Physics
Chemistry
Source (journal)
Plasma sources science and technology / Institute of Physics. - Bristol, 1992, currens
Volume/pages
25(2016):5, 15 p.
ISSN
0963-0252
0963-0252
Article Reference
055016
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
Plasma-based CO2 conversion is gaining increasing interest worldwide. A large research effort is devoted to improving the energy efficiency. For this purpose, it is very important to understand the underlying mechanisms of the CO2 conversion. The latter can be obtained by computer modeling, describing in detail the behavior of the various plasma species and all relevant chemical processes. However, the accuracy of the modeling results critically depends on the accuracy of the assumed input data, like cross sections. This is especially true for the cross section of electron impact dissociation, as the latter process is believed to proceed through electron impact excitation, but it is not clear from the literature which excitation channels effectively lead to dissociation. Therefore, the present paper discusses the effect of different electron impact dissociation cross sections reported in the literature on the calculated CO2 conversion, for a dielectric barrier discharge (DBD) and a microwave (MW) plasma. Comparison is made to experimental data for the DBD case, to elucidate which cross section might be the most realistic. This comparison reveals that the cross sections proposed by Itikawa and by Polak and Slovetsky both seem to underestimate the CO2 conversion. The cross sections recommended by Phelps with thresholds of 7 eV and 10.5 eV yield a CO2 conversion only slightly lower than the experimental data, but the sum of both cross sections overestimates the values, indicating that these cross sections represent dissociation, but most probably also include other (pure excitation) channels. Our calculations indicate that the choice of the electron impact dissociation cross section is crucial for the DBD, where this process is the dominant mechanism for CO2 conversion. In the MW plasma, it is only significant at pressures up to 100 mbar, while it is of minor importance for higher pressures, when dissociation proceeds mainly through collisions of CO2 with heavy particles.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/9ea1db/135070.pdf
E-info
https://repository.uantwerpen.be/docman/iruaauth/240735/135070.pdf
Handle