Humidity effects on surface dielectric barrier discharge for gaseous naphthalene decomposition

Abstract

Experiments are performed using dry and humid air to clarify the effects of water vapour on the characteristics of surface dielectric barrier discharge (SDBD) and investigate its impact on the performance of the SDBD for decomposition of gaseous naphthalene in air stream. The current characteristics, including the discharge and the capacitive currents, are deeply analyzed and the discharge mechanism is explored. The results confirmed that the humidity affected the microdischarge distribution without affecting the discharge mode. Interestingly, it is found that the water vapour had a significant influence on the capacitance of the reactor due to its deposition on the discharge electrode and the dielectric, which, in turn, affects the power loss in the dielectric and the total power consumed in the reactor. Thus, the factor of the humidity effect on the power loss in the dielectric should be considered in addition to its effect on the attachment coefficient. Additionally, there was an optimum level of the humidity for the decomposition of naphthalene in the SDBD, and its value depended on the gas composition, where the maximum naphthalene decomposition efficiency in O2/H2O is achieved at the humidity level ∼10%, which was lower than that obtained in air/H2O (∼28%). The results also revealed that the role of the humidity in the decomposition efficiency was not significant in the humidified O2 at high power level. This was attributed to the significant increase in oxygen-derived species (such as O atoms and O3) at high power, which was enough to overcome the negative effects of the humidity.

Fundamental Properties and Applications of Dielectric Barrier Discharges in Plasma‐Catalytic Processes at Atmospheric Pressure

“…The same setup was used for the gas‐phase decomposition of naphthalene in dry and humid air. The decomposition efficiency again strongly depended on the applied voltage and was derived to be around 90 % for 6 kV and a relative humidity between 0 % and 60 % .…”

Reduction of T‐2 and HT‐2 mycotoxins by atmospheric cold plasma and its impact on quality changes and germination of wheat grains

“…However, RH levels were significantly ( P < 0.05) increased after the ACP treatment using 100% N 2 and 80% N 2 + 20% O 2 for both treatment times (Table 2), which might be due to a minor leak in the ACP‐treatment chamber. In short, the increase of reactive species concentrations observed in this study was due to the presence of oxygen molecules, energy density generated by ACP, and the contribution of RH (Abdelaziz et al., 2018; Abdelaziz et al., 2019; Mastanaiah et al., 2013; Osawa et al., 2017).…”

Plasma-assisted removal of methanol in N2, dry and humidified air using a dielectric barrier discharge (DBD) reactor

“…Here, the radicals H˙ and OH˙ are generated through the electron impact dissociation and excitation reaction of H 2 O molecules as shown in R(15)–R(18). 3,43 H 2 O + e → OH˙ + H˙ + ee + O 2 → e + O( 1 D) + O( 3 P)O( 1 D) + H 2 O → 2OH˙…”