A chemical‐kinetic model of DBDs in Ar‐H2O mixtures. Issue 8 (19th March 2020) - Klages, Claus‐Peter
Abstract: A simplified chemical‐kinetic model was applied to Ar‐H2 O dielectric‐barrier discharges (DBDs), presuming that dissociation processes are only due to energy transfer from excited Ar species. Good agreement was obtained between the densities of HO, H2, and O2 and experimental data from the literature, whereas a discrepancy for H2 O2 could not be explained. The model is useful for designing DBD reactors and process development. Steady‐state densities of H atoms increase with decreasing fractions of x H 2 O which should be kept below 0.1% to obtain a large zone of virtually constant and large H‐atom density in the DBD reactor, whereas the HO density is hardly affected by x H 2 O . O2 contaminations must be kept well below 100 ppm in to attain maximum H‐atom densities. Abstract : A dielectric‐barrier discharge (DBD) in an Ar/H2 O mixture is an efficient source of H atoms and HO radicals. The temporal evolution of discharge‐gap‐averaged species densities, including O, O2, O3, HO, HO2, H2 O, and H2 O2, in an Ar/H2 O gas stream passing through the DBD is modeled using the simplifying assumption that dissociation processes are only due to reaction with excited Ar species, summarized in the model as a single "lumped species" Ar*. Results of the calculation, which are in good agreement with several experimental data taken from the literature, may be used to derive guidelines for reactor design and process development.