Study On Synergistic Catalytic Oxidation Of NO In Flue Gas With Dielectric Barrier Discharge

Nitrogen oxides（NOx）emitted during fossil fuel combustion and industrial production is one of the main atmospheric pollutants.NOx have devastating effects on ecosystems and human health,so how to control NOx emissions has caused widespread concern.As more than 90%of NOx emitted from coal-fired flue gas is NO,which is difficult to remove by general pollutant control devices,so the removal of NO is a key step in the de-Nox process.Since Non-thermal plasma technology generates a large amount of active materials during the reaction process and can effectively remove most of the pollutants,it has been widely studied in the field of pollutant control.With the development and progress of plasma technology,Plasma catalysis technology has gradually attracted widespread attention in the academic circle.This article mainly focuses on the study of dielectric barrier electric（DBD）plasma to remove NO from flue gas and its synergistic effect with Co-Mn/Ti catalyst.The main work and research results are as bellow:（1）In this experiment,the structure and other parameters in the plasma discharge system are optimized to obtain higher NO removal efficiency,the research shows:By optimizing the reactor structure,electrical and gas parameters,at an energy density of 1218 J/L,the NO removal rate is 77.26%,which can effectively improve the removal effect of NO.Compared to quartz and ceramics,corundum as a dielectric material can enhance the removal rate of NO;the use of copper wires as high-voltage electrodes enhances secondary electron emission,it also improves the removal rate of NO.There exists most optimized spiral diameter and wire diameter,when the spiral diameter is 6 mm and the wire diameter is 1 mm,the optimal NO removal rate is achieved.Increasing the temperature is beneficial for the removal of NO,when the temperature is 85℃,the removal rate of NO can reach 85.57%;If O ₂ exists,it will compete with N₂for High-energy electrons generated during discharge,then reduce the removal rate of NO,the presence of SO₂ and water vapor can inhibit the removal of NO and NOx.In this experiment,we combined dielectri c barrier discharge and a Co-Mn/Ti catalyst were used to oxidize NO in the flue gas,experimental result shows that compared with the DBD process,t he combination of DBD and Co-Mn/Ti catalyst shows excellent oxidation performance.（2）In this experiment,we combined dielectric barrier discharge and a Co-Mn/Ti catalyst were used to oxidize NO in the flue gas,experimental result shows that compared with the DBD process,the combination of DBD and Co-Mn/Ti catalyst shows excellent oxid ation performance.Approximately 91.3%of the NO was obtained when the 0.1 Co-Mn/Ti catalyst was placed downstream the discharge reactor at 45.2 W.A minimum NO concentration was found with a change in the reaction temperature at 100℃.H₂O significantly inhibited the NO oxidation,but NO oxidation efficiency could recover to the initial level after removing H₂O.SO₂not only restrained the NO oxidation,but resulted in the irreversible deactivation as well.The interaction of Co and Mn in a certain proportion on the catalyst leaded to the formation of more surface oxygen species,which favored the deep oxidation of existing NO to N ₂O₅.