Improvement of deoxidization efficiency of nitric monoxide by shortening pulse width of semiconductor opening switch pulse power generator

Abstract

The deoxidization efficiency of nitric monoxide (NO) was improved by shortening the pulse width of the voltage applied to a corona reactor. The deoxidization efficiency of NO was evaluated as the NO removal efficiency in nitrogen (N 2 ) gas containing 200 ppm NO. The corona reactor had a coaxial geometry and consisted of center high-voltage wire and outer grounded cylinder electrodes. A nanosecond high-voltage pulse was generated using an inductive energy storage pulse power circuit with a semiconductor opening switch and was applied to the center wire electrode in the corona reactor. Fast recovery diodes were utilized as a semiconductor opening switch. The pulse width of the applied voltage was reduced from 21 to 14 ns with the arrester connected in parallel to the reactor. The energy efficiency for NO removal was improved from 8.2 to 35.7 g kW %1 h %1 with the arrester connected. The pulse width was also reduced to 8 ns by optimizing the circuit parameters. It was confirmed from observation with an intensified charge-coupled device (ICCD) camera that the streamer corona discharge transited to a glowlike discharge after the streamer propagated from the center wire electrode to the outer cylinder electrode. The duration of the glowlike phase was reduced with the arrester connected. The energy consumed in the glowlike phase was also reduced from 15.7 to 4.6 mJ with the arrester connected.

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

“…Unfortunately, besides converting NO to other compounds, the plasma also generates NO. Two important reactions that produce new NO with atomic oxygen and (Sub)nanosecond transient plasma for atmospheric plasma processing experiments: application to ozone gene atomic nitrogen are N + O → NO, (14) NO…”

“…According to the results, the concentrations of NO and NO 2 are zero for the 135-ppm results at high energy densities, yet the N O concentrations steadily increases with the energy density, indicating the presence of NO 2 . Therefore, the NO production reaction (14) has to play an important role. The constant production of new NO will result in new NO 2 , which will consequently be converted to N 2 O.…”

“…For the production of NO through reaction (14), atomic nitrogen is required. Therefore, if the production of NO by the plasma is more pronounced for positive pulses, it is likely that more atomic nitrogen is produced for the positive pulses.…”

“…In our work, we use short high voltage pulses to generate transient plasma, because recent research has shown that transient plasmas generated by very short nanosecond high-voltage pulses are very efficient for a variety of applications [9,10,11,12,13,14,15,16]. Some researches have shown that the pulse duration of the applied high-voltage pulse has a significant influence on the radical yield of the transient plasmas generated with these pulses (shorter pulses result in higher yields) [9,15,10,11].…”

Experimental setup for temporally and spatially resolved ICCD imaging of (sub)nanosecond streamer plasma

“…19 Previous research shows that non-thermal plasma generated by very short (nanosecond) high-voltage pulses is very efficient for a variety of applications. [20][21][22][23][24][25][26][27] Overall, researches have noted that the pulse duration of the applied high-voltage pulse has a significant influence on the radical yield of the transient plasmas generated with these pulses; shorter pulses result in higher yields. [20][21][22]26 To study and understand this phenomenon, we developed a nanosecond pulse source that produces even shorter and faster pulses than realized by other research groups.…”