Dielectric-Boosted Gliding Arc Discharge for N2 Fixation into NOx

Abstract

Plasma nitrogen fixation technology is of great significance in solving the problem of nitrogen fertilizer resource shortage, saving energy and reducing carbon emission, promoting sustainable development of agriculture and promoting resource recycling. To enhance the efficiency and treatment capacity of the two-dimensional, blade-type gliding arc nitrogen fixation reaction, a dielectric-boosted gliding arc discharge reactor with a 50-mm-diameter quartz dielectric (DBGAD_Φ50) was used to conduct N₂ fixation into NO_x. The impact of reactor parameters and gas parameters on the nitrogen fixation reaction was systematically investigated in this study. The findings revealed that the DBGAD_Φ50 significantly improved the nitrogen fixation effect. At a specific input energy of 2.7 kJ/L, the concentration of NO_x generated by the dielectric-boosted gliding arc air discharge was 1.12 times that of the conventional gliding arc discharge (GAD). By utilizing the DBGAD_Φ50 reactor, the energy efficiency of 6.83 g/kW h was achieved at a gas flow rate of 5.6 L/min. Appropriately increasing O₂ concentration favors the production of NO_x. In the DBGAD_Φ50, the NO_x concentration was 1.33 times higher than that in the air atmosphere when the added O₂ volume fraction reached 30%. Performance can be further enhanced by adding TiO₂ catalyst particles to the surface of the quartz dielectric to form a catalyst layer approximately 5 mm thick. At an O₂ concentration of 30%, the DBGAD_Φ50 reactor loaded with TiO₂ increased NO_x concentration by 26% and energy efficiency by 49%, respectively, resulting in an efficiency of 14.9 g/kW h compared to the case without catalyst.