Influence of Temperature on Gas-Phase Toluene Decomposition in Plasma-Catalytic System

Abstract

The decomposition of toluene on c-alumina, MnO 2 -alumina and Ag 2 Oalumina catalysts in a plasma-catalytic reactor is tested. A comparison between catalytic, catalyst-after-plasma and catalyst-in-plasma systems is made in 150-400°C temperature range. An Arrhenius plot is made in order to deduce the mechanism of plasma activation. It was found that there is no difference between the measured activation energy for catalytic and catalyst-after-plasma systems. On the other hand it was found that plasma could activate catalyst placed inside of the discharge. Plasma treatment decreases the activation energy for the silver-alumina catalyst but does not increase the number of active centers on the surface of Ag 2 O-alumina. In case of MnO 2 -alumina, the activation mechanism is different: plasma does not change the activation energy and but does increase its efficiency due to formation of additional active centers. The mechanism of catalyst activation in plasma, which includes the structural change of manganese ions, is suggested.

Effects of Temperature on Benzene Oxidation in Dielectric Barrier Discharges

“…A similar result is also obtained with toluene and propane [9]. Demidyuk and Whitehead [10] studied the effect of temperature on the conversion of gas phase toluene. Magureanu et al [11] have studied effects of the temperature on the toluene conversion and the CO 2 yield in a dielectric barrier discharge (DBD) combined with Mnbased phosphate catalysts placed downstream of the plasma reactor, it is found that in the range of 0-400°C, both the conversion and the CO 2 yield increase with the temperature.…”

“…There are a number of publications investigating the effect of gas temperature on the conversion of VOCs [8][9][10][11][12]. It is found that an increase of gas temperature is beneficial to CH 4 decomposition [8].…”

Plasma Reactivity and Plasma-Surface Interactions During Treatment of Toluene by a Dielectric Barrier Discharge

“…Since the first work by Yamamoto et al [11], electron beams as well as several types of discharge such as dielectric barrier (DBD) or corona discharges, capillary discharge, DC glow discharge, multi hollow needle discharge, and also various types of packed-bed reactors, have been studied for the treatment of toluene in air [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Some results were published concerning the efficiency of the nitrogen plasma to remove toluene and about the influence of the oxygen percentage added to N 2 [15,19,23,24,29].…”

Plasma catalysis: A solution for environmental problems

“…Another way in which information about the mechanism of plasma-assisted catalysis can be derived is to use the temperature-dependent data to extract kinetic information via an Arrhenius-type analysis. We have performed such an analysis for the destruction of toluene in an atmospheric-pressure air stream using thermal catalysis and plasma-assisted catalysis in both a one-and two-stage system [17]. The catalysts used were Ag/γ-Al 2 O 3 and Mn 2 O 3 /γ-Al 2 O 3 .…”