Effect of water adding on kinetics of barrier discharge in air

Abstract

This work presents the results of theoretical and experimental studies on the effect of air humidity on the kinetics of plasma-chemical processes in a plasma-chemical reactor consisting of 16 volume barrier discharges and an 80 L volume working chamber. The component content of active species both in the discharge gap and in the working chamber was calculated under the conditions of the use of dry (RH = 20%) and wet (RH = 80%) ambient air, a specific discharge power of 1.5 W cm−3, a temperature of the gas medium in the discharge of 300–500 K and various residence times of the species in the discharge volume. The calculations were performed for the steady-state effective electric field in the discharge gap equal to 20 kV cm−1. It is found that, in spite of the difference between the rotational temperatures of nitrogen molecules in discharges in dry and wet air (≈400 K and ≈440 K, respectively), the best agreement between the calculations and the experiments for both the RH values is observed for the same calculated temperature of the gas medium in the discharge (≈425 K). In most cases, the calculated concentrations of O3, HNO3, HNO2, N2O5 and NO3 in the discharge gap and in the working chamber are in fairly good agreement with the respective measured data.