Speaker
Vasco Guerra
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.3012.pdf
Energy transfer pathways in CO2-containing DC discharges
V. Guerra1, T. Silva1, P. Ogloblina1, M. Grofulović1, L. Terraz1, H. Rodrigues1,
C. Gonçalves, A. Silva1, N. Pinhão1, C. D. Pintassilgo1,2, A. Tejero-del-Caz1, L. L. Alves1,
A. S. Morillo-Candas3 and O. Guaitella3
1
IPFN, Instituto Superior Técnico, Universidade de Lisboa, Portugal
2
Dep. de Engenharia Física, Faculdade de Engenharia, Universidade do Porto, Portugal
3
LPP, Ecole Polytechnique, UPMC, Université Paris Sud-11, CNRS, Palaiseau, France
CO2-containing plasmas constitute a hot topic nowadays, due to their importance in CO2
reforming and the production of solar fuels [1,2] and in Mars-related studies [3,4]. A key
step seems to reside in the selective excitation of the CO2 asymmetric stretching vibrational
mode, while limiting the losses by gas heating. The subsequent vibration-vibration (V-V)
up-pumping may enhance dissociation and favour CO2 conversion at a low energy cost
[1,2]. This work presents a thorough theoretical, modelling and experimental investigation
of discharges in pure CO2 and in CO2 mixtures with N2, CH4 and Ar and their afterglows,
operating at pressures around 1 Torr, discharge currents of 10s of mA, either in a
continuous or a pulsed regime. The basis of the model was presented in [5]. It comprises a
detailed state-to-state kinetics of CO2 vibrationally excited levels, coupled to the gas phase
chemistry and to the homogeneous electron Boltzmann equation describing the electron
kinetics. The model is validated from the comparison with the measurements of the
populations of several heavy species, e.g. O, CO, CO2(v) and C2Hx. Several phenomena are
presented and discussed, such as the transfer of vibrational energy from N2 to the CO2
asymmetric stretching mode, the efficiency of dry reforming of methane, the influence of
shifting the electron energy distribution function to higher energies due to Ar addition, or
the main routes towards enhanced reactivity.
Acknowledgments: This work was partially supported by the Portuguese FCT, under Projects
UID/FIS/50010/2013, PTDC/ FIS-PLA/1420/2014 (PREMiERE) and 1243/2014 (KIT-PLASMEBA), and
grants PD/BD/ 105884/2014 and 114398/2016 (PD-F APPLAuSE). VG has been supported by LABEX
Plas@par receiving financial aid managed by ANR under the reference ANR-11-IDEX-0004-02.
References
[1] A Bogaerts et al 2017 Plasma Sources Sci. Technol. 26 063001
[2] A. P. H. Goede et al 2014 EPJ Web of Conferences 79 01005
[3] A. Bultel and J. Annaloro 2013 Plasma Sources Sci. Technol. 22 25008
[4] V. Guerra et al 2017 Plasma Sources Sci. Technol 26 1
[5] T. Silva et al 2018 Plasma Sources Sci. Technol 27 015019
