Pulsed power production of ozone in O/sub 2//N/sub 2/ in a coaxial reactor without dielectric layer

Abstract

Very short duration pulsed streamer discharges have been used to produce ozone in a gas mixture of nitrogen and oxygen at atmospheric pressure. The ratio of nitrogen to oxygen in the mixture was varied in the range from 2.510.5 to 0.5/2.5, while maintaining a total flow rate of 3 lr'min. The production of ozone was found to be higher for a specific mixture ratio of N2/02 than that in oxygen or in dry air. The production of ozone in 0 2 was higher than that in dry air, The production yield of ozone (gkWh) increased with decreasing nitrogen in the 02/Nz mixture. It has been found that the peak of the streamer discharge current decreased with time after application of the pulsed power. This decrease in the current corresponded with the increase in the ozone production and is attributed to the loss of electrons in the discharge current due to their attachment to ozone to form negative ions.

(Sub)nanosecond transient plasma for atmospheric plasma processing experiments: application to ozone generation and NO removal

“…At first glance, the second observation is in contradiction with the first observation because a higher applied voltage increases the energy density. In some of the studies that we cited the ozone yield indeed decreased with the applied voltage [49,12,60], but in other studies the yields increased with the applied voltage [23,22], just as in some of our experiments. Therefore, the effect that the voltage amplitude has on the ozone yield appears a specific effect for each reactor configuration and the consequent streamer phases (primary, or primary+secondary) at each applied voltage.…”

“…An obvious choice to make is: to which application do we apply our nanosecond pulse technology? Some of the classical air-purification processes are the production of ozone [21,22,23,8,24] and the removal/conversion of nitrogen oxides (NO x ) [25,26,21,27,28,29,16,30], sulfur oxides (SO x ) [27,31,32,33], volatile organic compounds (VOCs) [34,35,36,37], tar [6,38], odour [39,40,41], particulate matter (PM) [27,41] and biological particles [41,42,43,44,45].…”

“…The yields of ozone generation in air that researchers report are generally in the range of 15-150 g•kWh −1 [21,48,7,22,24] for different types of plasmas and reactor configurations. Wang et al report yields as high as 239 g•kWh −1 ‡ with their nanosecond pulse source and show in an extensive map the comparisons between different discharge methods and the very good results of nanosecond pulsed discharges [49].…”

Implementación de la modulación por densidad de pulsos PDM en un sistema de generación de ozono y su efecto en la curva característica de eficiencia

“…Una metodología para incrementar la eficiencia del sistema de generación de ozono, considera el mejoramiento de la eficiencia de, al menos, uno de los dos bloques principales: la fuente de alto voltaje o la celda DBD. Entre las alternativas para mejorar la eficiencia de la fuente se pueden citar los pulsos de corta duración [7][8][9][10]. Sin embargo, actualmente se tienen grandes limitantes técnicas en la implementación de la fuente para generar estos pulsos; también se ha experimentado con el aumento de la frecuencia y la operación bajo resonancia [11][12][13].…”

Industrial Applications of Pulsed Power Technology

“…Nonthermal plasmas have many kinds of chemically activate radicals, such as O, O 3 , N, N * , N 2 + and OH, which are generated by the dissociation and ionization of the ambient gases caused by the impact of energetic electrons. Using pulsed power technology, nonthermal plasmas have been generated by a pulsed electron beam [29] or a pulsed streamer discharge [30], and have been used to treat nitric oxides (NO X ) [31][32][33][34], sulfur dioxide (SO 2 ) [35][36][37], carbon dioxide (CO 2 ) [38] and volatile organic compounds (VOCs) [39,40], and to generate ozone [41][42][43][44][45][46]. Particularly, the treatment of exhaust gases (NO X and SO 2 ) using a pulsed streamer discharge has been studied for the past decade.…”