Performance evaluation of discharge plasma process for gaseous pollutant removal

Performance evaluation of non-thermal plasma (NTP) process has been carried out using NO as a model gas. The experimental results were evaluated using a simple model, which relates the change of NO concentration with specific input energy (SIE) (kJ/Nm3). The results were also evaluated using the well-known parameters of energy cost, energy yield (EY) and G-value. As the SIE increased, the EY and the G-value decreased while the energy cost increased even under a given reaction condition. Based on these parameters best results were found in the smaller SIE region where the NO removal is poor. An approach has been developed to use the constant (hereafter referred to as energy constant kE (Nm3/kJ)) in a simple model to evaluate the system performance of non-thermal plasma reactor instead of conventional parameters. Unlike the three conventional parameters, the energy constant was not influenced by the SIE level under the range tested in the present work. The effects of various reaction conditions, such as initial concentration of NO, temperature, additive on the energy constant kE have been investigated. The comparison of kE values for different NO concentrations clearly showed that the NTP process is more efficient in treating gaseous pollutant in low concentration. The increase of NO concentration exponentially decreased the energy constant. Gas temperature showed a similar effect. The significance of the influence of the tested parameters on the energy constant kE has been found to be of the order of the gas composition, the initial concentration, and the gas temperature. Among the additives tested in this study, ethylene made the energy constant kE to a maximum value of 242×10−3.