Application of Non-Thermal Plasma for NOx Reduction in the Flue Gases

Abstract

Over the years, ever more stringent requirements on the pollutant emissions, especially NO X , from combustion systems burning natural gas are introduced by the European Union (EU). Among all NO X reduction methods, the flue gas treatment by plasma is widely applied and could be used for both small scale and domestic combustion systems. However, the removal efficiency depends on concentrations of oxygen, water vapor, traces of hydrocarbons, and nitrogen oxides in flue gas. In order to analyze the application of the NO X reduction for small-scale or domestic combustion systems, experiments of NO X reduction by non-thermal plasma from real flue gases originating from premixed methane combustion at different equivalence ratio (ER) values were performed. It was determined that the residual oxygen in flue gas plays an important role for improvement of NO to NO 2 oxidation efficiency when O 2 concentrations are equal to or higher than 6%. The power consumption for the plasma oxidation constituted approximately 1% of the burner power. In the case of ozone treatment, the addition of O 3 to flue gas showed even more promising results as NO formed during combustion was fully oxidized to NO 2 at all ER values.

A Review about the Recent Advances in Selected NonThermal Plasma Assisted Solid–Gas Phase Chemical Processes

“…Paulauskas et al [91] investigated the NO x removal via direct plasma treatment from a real flue gas originated by methane combustion, finding that the residual oxygen plays a crucial role in the oxidation of NO to NO 2 when oxygen concentrations are ≥6%. Moreover, when oxygen concentrations are below the 6%, the NO removal efficiency is increased because of other processes.…”

Reduced electric field and gas temperature effects on chemical product dynamics in air surface dielectric barrier discharges: from macro-physical parameters to micro-chemical mechanisms

“…In this regard, it is necessary to reveal the mechanisms of the change in chemical product composition. As can be summarized from prior studies, the detection methods [7][8][9][10][11][12] for chemical products are mostly UV absorption spectroscopy and Fourier infrared spectroscopy (FTIR), and the researches on chemical products change mechanisms have focused on two main topics: power [11][12][13][14][15][16][17] and gas temperature. 18,19 For instance, Shimizu et al 11 measured the temporal development of O 3 concentration in a confined volume using UV absorption spectroscopy at 254 nm.…”

High-Voltage Nanosecond Discharge as a Means of Fast Energy Switching

“…Nanosecond discharges in gases in a sharply inhomogeneous electric fields have attracted the attention of researchers all over the world [1][2][3][4][5][6][7][8][9][10]. The reason for this is the wide range of applications for such discharges.…”