Search

In this paper, the effects of the applied voltage modes on the positive corona discharge morphology and NO removal characteristics from air streams are experimentally investigated. By using a DC superimposed high frequency AC power supply (10-60 kHz), a uniform streamer corona can be generated, which is also less sensitive to electrode mis-arrangements. Hermstein glow can he transferred to streamer corona if the peak-to-peak voltage is larger than 1.0 kV at the voltage change rate of 0.2 kV//spl mu/s. A significant amount of NO removal is observed under streamer corona. For the Hermstein glow, the removal is negligible. Moreover, the basic principle for designing AC/DC energized streamer corona is also presented in this paper.

Transmission line transformers (TLTs) are usually used for impedance match. In this paper, we present a novel circuit topology based on multiple switches and TLTs for both the impedance match and synchronization of multiple switches. In contrast to the Marx pulse generator, our proposed pulsed power systems produce high levels of pulsed power not only at higher voltages but also at higher currents.

Gasification is considered as an efficient way to utilize biomass as an energy source or for fuel production. One of the obstacles for commercial utilization is the production of tars or heavy hydrocarbons along with the producer gas. Tar removal posses a serious challenge. Conventional methods employ catalytic or thermal cracking or scrubbing techniques. The present paper investigates non-thermal plasma as an alternative approach. Experimental results indicate energy requirement to be about 400 J/L for removal of naphthalene from synthetic producer gas at 200°C. The main pathway for tar removal by pulsed corona at the investigated temperatures is dry reforming by CO2. For commercial application, the key issue is related to the energy consumption of the process. In addition, another requirement is that fuel gas cleaning should be done at high temperatures in order to integrate with the downstream process equipments. The paper intends to provide an insight into pulsed corona plasma treatment of fuel gas at high temperatures.