Analysis of ozone generation in a planar atmospheric pressure air dielectric barrier discharge reactor

Abstract

This work investigates O3 production in a planar atmospheric pressure air dielectric barrier discharge reactor numerically and experimentally. The surface temperature of the reactor is measured by an infrared (IR) thermal imager, and the O3 densities of cases in the reactive zone are measured by ultraviolet absorption spectroscopy. The 1.5D plasma fluid model (PFM) with transverse convection is employed to capture the average properties of a single microdischarge (MD) generated in the reactor and is integrated with the 3D gas flow model for modeling species densities in the reactor. The simulated temperature distribution of the reactor surface is validated by that measured and the simulated O3 densities agree with those measured at different locations and flow rates. In the 1.5D PFM, the simulated results show that the O3 molecules produced in the case of 4 SLM are much more than those produced in the case of 1 SLM though the O atoms produced in the case of 1 SLM are around 20 % more than those produced in the case of 4 SLM. In the case of 1 SLM, more than 48% of O3 molecular generated are destructed, while only around 14% of O3 molecules are destructed in the case of 4 SLM. The analysis shows that around 73% of O atoms generated in the 1.5D PFM are consumed in the formation of O3 molecules in the case of 4 SLM, while only 18% of O atoms generated in the case of 1 SLM are consumed in the formation of O3 molecules. The overall O3 yield efficiency reaches 97 g/kWh with the O3 concentration increasing to 2700 ppm in the case of 4 SLM, while the O3 yield efficiency decreases to 10 g/kWh and O3 concentration drops to 1400 ppm in the case of 1 SLM.

Kinetic model of grating-like DBD fed with flowing humid air

“…In terms of a higher discharge power when temperature matters, the model should be modified since the rate constants of most chemical reactions are the function of temperature. For the discharge model, the gas temperature in the plasma region can be experimentally measured by methods like N 2 emission band fitting [56,57] or numerically calculated by considering the plasma heating mechanisms (electron elastic collisions, ionic Joule heating, and exothermic reactions) together with the heat transfer processes [31,58]. For the afterglow model, for simplicity, the plasma can be treated as a heating source which can be integrated with the heat transfer equation to obtain the spatial distribution of gas temperature [31].…”

“…For the discharge model, the gas temperature in the plasma region can be experimentally measured by methods like N 2 emission band fitting [56,57] or numerically calculated by considering the plasma heating mechanisms (electron elastic collisions, ionic Joule heating, and exothermic reactions) together with the heat transfer processes [31,58]. For the afterglow model, for simplicity, the plasma can be treated as a heating source which can be integrated with the heat transfer equation to obtain the spatial distribution of gas temperature [31]. It is also noted that the plug flow model of the air DBD in this work is kind of different from that of an APPJ.…”

“…Several reports have applied a coupled model to correlate the chemistry process to the discharge process. For instance, Lin et al coupled a 1.5D plasma fluid model and a 3D gas flow model to study the gas heating properties and mechanisms in a DBD reactor microdischarge [30] or the O 3 generation properties influenced by the gas flow rate [31].…”

Inactivation of SARS CoV-2 on porous and nonporous surfaces by compact portable plasma reactor

“…Two to three repeats were performed for each exposure time to gain statistical confidence and standard deviation observed in those repeats were used to represent error bars in the graph. Variations in ozone concentrations measured at the center of the 3 chambers at different times can be attributed to the difference in test chamber volumes, variations in atmospheric air conditions (Nazaroff and Weschler, 2022) and limitations associated with experimental ozone measurements due to unstable nature of Frontiers in Bioengineering and Biotechnology frontiersin.org ozone that result in decomposition of ozone to oxygen (Choudhury et al, 2022;Lin et al, 2023). Minimum ozone concentrations required to obtain complete inactivation (4-5 log reduction) of SARS-CoV-2/surrogate was found to be 300-550 ppm based on material type and chamber volume.…”

Characterization of OH species in kHz air/H2O atmospheric pressure dielectric barrier discharges

“…The DFM was further integrated with a 3D background gas model (BGM), solving the governing equations of the working gases to model the flow velocity, gas temperature, and distributions of working gases, as a complete model to predict the concentrations of reactive species (i.e. O 3 ) generated in the reactive section at different locations under a wide range of operating conditions with the gas temperature characterized [18,19]. The average species sources produced by the MD were considered in the species equations solved by the BGM through the proposed equivalent reactions to generate the equivalent amounts of related species in the reactor as those generated from MDs in the same volume.…”