NITROGEN OXIDES ABATEMENT FROM FLUE GAS VIA NON-THERMAL PLASMA

Abstract

This research investigated the use of dielectric-barrier-discharge non-thermal plasma (DBD-NTP) for nitrogen oxide (NOx) abatement in flue-gas applications, combining ozone generation and its subsequent utilisation for NO oxidation. A systematic experimental was conducted, comprising verification of the inverted tracer-gas method, evaluation of ozone-generation characteristics under various discharge parameters, up-scaling of multi-cell reactors, and ozone-assisted oxidation of NO in real diesel-flue-gas streams. The inverted tracer-gas technique was validated as a reliable and economical approach for determining volumetric flow rates, maintaining strong linearity (R2 ≈ 0.99) across 25–210 °C. Ozone generation was strongly influenced by discharge voltage, frequency, oxygen concentration, and gas-flow rate. The three-cell reactor achieved 11946 ppm ozone and 0.29 g/min production rate, while the two-cell configuration revealed the highest overall energy efficiency (6.21 µg/J). In real flue-gas experiments, ozone injection effectively converted NO to NO2, achieving up to 50 % conversion with 0.815 µg/J efficiency at optimal conditions (O3/NO ≈ 2.35).These findings demonstrate that DBD-NTP technology provides a low-temperature, modular, and scalable approach for plasma-assisted NOx control. Integration of ozone pre-oxidation with catalytic after-treatment offers a practical pathway toward enhanced DeNOx efficiency and reduced energy consumption in industrial exhaust systems.