A High-Concentration NOx Production System—Part 2: Optimization of the Nitrogen Oxides Yield

The authors report the results of design and experimental investigation of a high flow and high concentration NO
_x
production system based on a radio frequency (RF) plasma torch for a variety of applications. Unique gas dynamics of the first stage avoids plasma disturbance by feeding quenching gas and enables NO oxidation into NO
₂
with a total NO
_x
yield over 6% by mass. The developed system is tunable for NO
_x
concentration, scalable for higher flow, applicable for various technological processes, flexible for using different plasma gases and quenching media, including gases, liquids, and solids.