Division of Environmental Physics - User: student
Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava

DC glow discharges in atmospheric air as a source for VOC abatement

Machala Z., Marode E., Morvová M., Lukáč P.
Int. Symp. High Pres. Low Temp. Plasma Chemistry HAKONE IX, article 1O-03, Padova, Italy, August (2004)

download  

Abstract:

We present experimental investigations of a direct-current (DC) discharge in atmospheric pressure air with the aim of producing nonequilibrium plasma applicable for air pollution control. This pulseless continuous discharge occurs between two metal electrodes. Spectroscopic and electrical measurements confirm that the discharge is of the glow type. It operates with currents from 2 mA, voltages of some kV, current densities of 1-10 A/cm2, and gap lengths from a few mm to a few cm. Its voltage–current characteristics is descending. The gas temperature in the discharge is controlled by the current and by the gas flow velocity. The discharge generates highly ionized nonequilibrium air plasma with electron number densities of 10e12-10e13 cm-3 and gas temperatures of 1500-2500 K. We have successfully tested single and multiple discharges of this type in glass and copper tube reactors for the abatement of selected VOCs (cyclohexanone and toluene). Depending on the reactor type, discharge parameters and the injected energy density we obtained removal efficiencies of 30-95 %, with energy costs of 50-800 eV/molecule. In the VOC decomposition process, thermal discharge effects couple with volume reactions induced by radicals and other active species formed in the plasma, and with reactions occurring on electrode surfaces.

Citations:

1.)	R. Morent, C. Leys, J. Dewulf, D. Neirynck, J. Van Durme, H. Van Langenhove: DC-excited non-thermal plasmas for VOC abatement, J. Advanced Oxid.Technol. 10, 1 (2007) 127-136, SCI cit. 43 (2007) -------------
2.)	M. Magureanu, N. B. Mandache, E. Gaigneaux, C. Paun, V. I. Parvulescu: Toluene oxidation in a plasma-catalytic system, J. Appl. Phys. 99, Art. No.123301 (2006) (2006) -------------