NUMERICAL MODELING OF OZONE PRODUCTION IN A PULSED HOMOGENEOUS DISCHARGE - A PARAMETER STUDY

The pulsed volume discharge is an alternative for the efficient genera tion of ozone in compact systems, This paper presents a parameter stud y of the reactions in this kind of homogeneous discharge by using a nu merical model which solves plasma chemical kinetic rate and energy equ ations. Simulations are performed for 10(-9)-10(-5) s single pulses an d oxygen gas density in the range 1 < n < 10 amagat, initial gas tempe rature 100 < T-o < 300 K and normalized electric field of 100 < E/n < 200 Td. Results are presented of ozone generation efficiency versus oz one concentration for different parameter combinations. Two parameter regimes are identified and analyzed, In the plasma phase ozone formati on regime, where significant amounts of ozone are produced during the discharge pulse, it is found that higher ozone concentrations can be o btained than in the neutral phase ozone formation regime, where most o f the ozone is formed after the discharge pulse, In the two-step ozone formation process, the rate of conversion of atomic oxygen plays a ke y role, In both regimes the ozone generation efficiency increases as n is increased or T-o decreased, The maximum concentration is 3% at 10 amagat and 100 K. The results on ozone accumulation in multiple pulse discharges are presented, In contrast to the single pulse case, higher efficiency is achieved at lower gas density, This scaling can be expl ained by losses due to ion currents, A tradeoff can be made between oz one generation efficiency and the number of pulses required to reach a certain concentration, Thus, for example, an ozone concentration of 1 0% can be achieved in 15 pulses at 200 gO(3)/kWh, whereas 30 pulses wi th lower energy results in 300 gO(3)/kWh.